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City, Territory and Architecture
An interdisciplinary debate on project perspectives
Rethinking waste as a resource: insights from a low-income community in Accra, Ghana
Martin Oteng-Ababio1
City, Territory and Architecture volume 1, Article number: 10 (2014) Cite this article
Conventional solid waste management protocols and thinking generally tend to assume that waste already exits and therefore needs to be managed. Consequently, most models of solid waste management, especially in the developing countries including Ghana, are simply reactions to the presence of something that needs to be disposed of or discarded. This paper sees this conventional solid waste management philosophy as a potential barrier to an efficient and sustainable management and argues that adopting an integrated systemic approach will both help to control the processes that generate waste (including waste handling and utilization) and enable city managers to minimize waste generation in the first place. This paper uses a project initiated by a community-based organization in Ga Mashie (Accra) to explore the potential of converting household waste into a resource. Adopting a multiple research methodology, the study analyzes the characteristic and composition of waste generated within communities in Accra. The results show that a greater part of the 'waste' is recyclable or potentially recyclable and that a well-coordinated recycling programme will not only ensure a huge reduction of waste volume, but can equally lengthen the life of existing dumpsites and possibly, create wealth and reduce poverty. The paper argues that scaling up the project offers the local authority an opportunity to tap into the innovative strengths embedded in the project, particularly its physical and economic synergies, which may bolster community sustainable development.
"To waste, to destroy our natural resources, to skin and exhaust the land instead of using it so as to increase its usefulness, will result in undermining in the days of our children the very prosperity which we ought by right to hand down to them amplified and developed."
Theodore Roosevelt, Seventh Annual Message, December 3, 1907
The admonition from Roosevelt is an indication of society's long cherished dream of living in an environment of resourcefulness rather than wastefulness. Yet, as the world hurtles towards its urban future with the world's urban population increasing by two new people every second, and with 95 per cent of such increases taking place in cities of developing countries, nowhere is the impact more obvious than in society's "detritus," or solid waste (Hoorneweg and Bhada-Tata 2012). Studies show that currently, cities cover only 2% of the world's surface but generate 70% of the world's waste (Zaaman and Lehman 2011). In Ghana, Accra produces conservatively 2,200 tonnes of solid waste daily, and is expected to reach 4,419 tonnes by 2030 (Oteng-Ababio 2010). The relationship between waste and cities is particularly threatening the future, in situation where practically everything is based on a throwaway mentality, which pays little regard to sustainability.
In countries where efficient solid waste management (SWM) policies have been instituted, including effective waste collection, segregation, transportation, storing, treatment and disposal, 'waste' is economically re-circulated (Medina 2005; Sternberg 2013). In such situations, SWM is not only seen as a necessary process to promote health and environmental safety, but also as presenting an opportunity to mine the largely untapped resources embedded in waste. The dilemma in Ghana is how to develop systems that can best utilize these inherent resources, even though the paper believes that the inability of city authorities to develop appropriate SWM policies cannot be wholly attributed to technical or economic reasons (see Grant and Oteng-Ababio 2012). It also has much to do with how waste is conceptualized and operationalized in the first place. Ojeda-Benitez et al. (2000) re-emphasizes the point when she opines that to appreciate the value of 'waste', it must be differentiated from refuse. To her, refuse refers to a situation where different kinds of waste are disposed of or mixed together in the same container, causing unpleasant odour and pollution, making it impossible for re-use. However, when kept separately with a minimum of order and care, such materials become waste to the original owner but may have some value for other persons.
In recent times, it appears that people's socio-cultural practices or throwaway mentality, where activities are designed to take 'resources,' make products and turn them into waste ('take-make-waste' attitude) are impacting negatively on the ecosystems, particularly with increasing population, improved technology and increased consumption. At the same time, waste is also becoming so diverse in its origin and forms, and so pervasive in its impacts, through terrestrial, aquatic, and atmospheric ecosystems that it has the potential to adversely affect both the inhabited and uninhabited parts of the world. The penchant of state officials also to unilaterally accept foreign SWM prescriptions during their international conferences, regardless of local technical or socio-economic circumstances and expecting overnight transformations, has worsened matters (see Ali 2010). The inherent uncertainty about 'local therapies' is part of an age-long debate but such tendency stifles local innovative resourcefulness. It also brings UN Sustainability City Program into question as per the present 'take-make-waste' attitude, neither industry nor the consumer has any incentive to use resources frugally. This creates chronic environmental concerns and pushes cities to grow in a disorderly manner, causing an accumulation of urban problems.
It is beyond the scope of this paper to venture into the debate on "the limits to growth" vis-à-vis resource consumption or the negative environmental impacts that will occur from wastes generated by an increasingly consumerist urban population. That said, the fear about these effects is warranted, particularly since nearly 95% of environmental damage occurs before a product is discarded as solid waste (Hoorneweg and Bhada-Tata 2012). This paper intends to shift the current emphasis from the "end-of-the-pipe approach", where waste is collected and disposed of (without any incentive to recycle), towards encouraging consumption within the waste stream. It is believed that most waste materials can cascade through a series of uses that can enhance job creation, decrease the need for 'natural resources' and eventually, the overall waste flows.
In what follows, the paper discusses the notion of waste and its value chain, highlighting on its implications for urban livelihoods and sustainable environmental management. Particular reference is given to the activities of a local non-governmental organization (NGO), Great Thinkers' Club, which has pioneered a youth enterprise from recycling of solid waste generated in James Town, a low-income community in Accra. The paper draws on the value chain thinking, demonstrating how the project has been designed synergistically to produce employment for the youth, through a range of valuable by-products of waste while, at the same time ensuring efficient SWM. Finally, the paper proposes a paradigm shift, which is intended to help all project stakeholders to appreciate waste as a resource.
The notion of waste and the value chain
Waste is waste?
Waste, otherwise termed rubbish, trash, junk or garbage depending on the type of material, or the region in question, is a complex, subjective and perhaps controversial issue. Though waste is generally seen as an unwanted or undesired material and a bothersome problem and sometimes, a health threat if improperly treated, it can in some cases, generate good business for some, when properly handled. The complexity of waste manifests in the difficulty and multiplicity of its definition and description, which is also contingent on who is looking at the subject matter: ordinary citizens, technicians, businessmen, politicians, activists (Progracz 2002). Since different approaches have been used in defining waste, it is notably a challenge to gather comparable data for example, between waste in rich and poor countries. Table 1 presents some definitions of waste.
Table 1 List of definitions of waste
These definitions do not resolve the uncertainties surrounding what waste is. What runs through them, however, is the fact that waste is something that its holder has disposed of or discarded. This creates the problem of distinguishing between 'dispose of' and discard, as both principally mean getting rid of. Cheyne and Purdue (1995), however, suggest that disposal is a deliberate and thoughtful act to put something in a suitable place (either for sales, transfer of ownership, etc), while discard implies outright rejection, with or without interest in its final destination, since that thing is seen as useless or undesirable.
Other studies (CEFIC 1995) also argue that it is not the nature of the material that determines whether it is a 'waste', but the actions or intentions of the holder. Therefore, only those materials for which the holder has no further use and which he discards or intends to discard are waste. Lox (1994) also see waste as "either an output with (a negative market) no economic value from an industrial system or any substance or object that has been used for its intended purpose (or served its intended function) by the consumer and will not be reused". This definition also appears deficient, since the last part of it creates an impression that a product is designed for a single purpose and therefore, as soon as the purpose is fulfilled, it turns to waste.
Gourlay (1992) exemplifies this deficiency using a dollop of mustard left on a plate, which he argues is neither useless nor lost its properties and queries if such a material only became waste just because the owner failed to use it. In his contribution to unravel the puzzle, Gourlay proposes a working definition for waste as "what we do not want or fail to use". However, his definition also appears more human-related and fails to properly account for the concept of production wastes, especially the issue of by-products that are not necessarily created from carelessness but unavoidably emanating from the production process itself.
Contributing to the debate, Stanbury (2005) attribute the complexity of the term waste to its genesis, which they traced to the Latin word uastus and which evinces several meanings; to ravage, to leave desolate or cultivate. To them, waste connotes inefficiency and mirrors situations where managers of entities fail to minimize cost or maximize output because they are not using the best technology available. Elwood and Patashik (1993) add another dimension when they blithely asserted that waste, like beauty, is in the eye of the beholder. It can thus be argued that since there is no such thing as waste in nature, then waste is a human concept. Within the ecosystem, recycling is rife, hence production and decomposition are well balanced and ensure stability and sustainability in natural systems.
Human engagement with the ecosystem, however, places much emphasis on its economic value, resulting in situations where production and consumption become the dominant activities. Such a system tends to be highly destructive, consuming massive natural capital and energy, which return into the environment as waste, requiring even more natural capital to be consumed in order to feed the system (Pongracz 2002). The presence of waste is therefore an indication of overconsumption and inefficient use of resources, since the capacity of the natural environment to absorb and process these materials is finite and the improper waste disposal results in the loss of valuable resources. From all indications, the main problem confronting most developing countries is the sheer volume of waste being produced and how 'waste' is conceptualized.
Re-defining solid waste management
Significantly, the goal of any legislation on waste is to protect the environment and public health. Consequently, the conventional SWM hierarchy adopted by most local authorities and their donor agencies includes a 5-staged process, involving waste reduction, re-use, recycle, incinerate, and safe disposal of the residual at landfills (Forbes et al. 2001). From that perspective, this paper re-affirms that waste and its management involves multi-faceted activities and processes, yet opines that an efficient SWM should include the supervision of such operations and maintenance of disposal sites, which the current hierarchy appears silent. The present models implicitly assume that waste already exists "in space" and needs to be managed and that, SWM is simply a reaction to the presence of something that needs to be eliminated.
Seeing waste with that lens may create a barrier to an efficient and sustainable SWM system and may negatively affect the overall decision related to the transport, reuse, and sale of materials. Conversely, this paper believes that preventing the accumulation of waste from the beginning maximizes resource efficiency and sustainable management. An optimal approach to SWM would be an integrative system-based approach that provides control over processes that generate waste, waste handling, and waste utilisation (IPCC 2007). Thus, the key to any effective SWM involves waste minimization that helps the reduction of the amount of things to be disposed of, and this includes:
Preventing and/or reducing the generation of waste at source;
Improving the quality of waste generated, such as reducing the hazard, and,
Encouraging re-use, recycling and recovery.
It is important to stress that minimizing the amount of things intended for disposal is only one of the options of waste minimization, which then reinforces the perception that 'the wasted thing' is already there to be disposed of. This contravenes the principal meaning of waste minimization, which is to avoid waste generation in the first place (Pongracz 2002). By inference, waste can be seen as a value concept, culturally construed, very subjective and may implicitly have a remote economic value.
Most developed countries have adopted the philosophy of waste minimization as the menu for their SWM systems, but scarcely has this informed policies in developing countries, where pressures of urbanization, land space for waste disposal and wanton destruction of natural resources are creating a bigger challenge (Baud et al. 2001). In Ghana, the individual local authorities (assemblies) are charged with the responsibility to manage waste in their respective jurisdiction and must do so in the most economically, socially and environmentally optimal manner possible (MLGRD 1999). Prior studies (Post and Obirih-Opareh 2002; Oteng-Ababio et al. 2013) have shown that waste management remains the single largest item on the assemblies' budget yet the most pernicious local pollutant (uncollected waste remains the leading contributor to local flooding and pollution). Equally important challenge confronting most authorities relates to their inability to appreciate waste as a resource as to date, and, as a consequence, waste separation remains alien or not properly address due to lack of finances. Even the National Environment and Sanitation Policy of 1996, and revised in 2010, remains loudly silent on waste minimization, creating a waste industry that is vague, dysfunctional and disjointed.
Earlier studies (see Hetherington 2004; Gregson et al. 2007; Adama 2012; Thieme 2013) highlight the fact that urban poverty and waste picking are inextricably linked with the urban poor engaging in scavenging as a survivalist strategy while at the same time, filling the vacuum created by the public sector-led SWM operations. There are also enough evidence showing that historically, communities have been resourceful to use waste as food for animals, fertilizer and as materials for second life products (Wilson et al. 2006). These studies point to a vibrant waste enterprise, devoid of policy or legislative, often tedious, unhygienic, unrecognized and potentially hazardous, whose contributions are rarely documented or quantified. These activities rank lowest in the waste recycling rung and participants are mostly the urban poor, especially women and children (Ahmed and Ali 2006). This paper is hopeful that more lessons can be gleaned from such informal operations in our quest for economically and environmentally cost effective SWM. Figure 1 establishes tractable pathways of making waste a resource through waste segregation at source, based on the value chain concept.
Pathways for managing waste as a resource (ISWM). Source: Author's construct.
On a broader scale, waste segregation reduces the burden of waste collection and disposal, minimizing loads of waste that need to be transported to dump sites. At the household level, there is need for capacity building on ways to reduce the amount of generated waste and these include recycling and re-using products. 'Re-use' involves using the product more than once for the same or a different purpose. Composting is also a good way of disposing of biodegradable waste materials, especially in residential areas and can provide compost for urban agriculture and create more local jobs. This paper believes that if municipal waste is to be harnessed to improve livelihoods, then government and its agencies must necessarily develop efficient markets and build a knowledge base around "what works".
Research location and methodology
The study area
To achieve the set goals, the study adopted multiple survey methods including key informant's interviews, participant observation and a comprehensive review of official and other documents to generate empirical data. The research was conducted in Accra, the political capital of Ghana, which also serves as its administrative, socio-economic and cultural hub, harbouring about 70% of all manufacturing activities (Grant 2009; Owusu et al. 2008). The research location is Ga Mashie (also called old Accra), the spiritual home of the Ga people, with a youthful population of about 100,000, mainly engaged in fishing (CHF International 2010). Living off fishing and trading, Ga Mashie (see Figure 2) is sub-divided into James Town or British Accra and Ussher Town or Dutch Accra. The community is one of the poorest in Accra, with the highest education level of majority being senior high school or its equivalent (UN-Habitat 2010). This is reflected in the area's poverty levels, recording an average monthly income of GH¢ 126.13 or USD 78.83a, against a regional (Greater Accra) average of GH¢ 544.00 or USD 340.00 (GSS Ghana Statistical Service 2008). The average number of people per house stands at 48, or 7 people per room, against 5.1 at the regional level (CHF International 2010).
Map of the study area. Source: Author's construct.
Waste generation in Accra
Waste is the most visible by-product of a resource-intensive, consumer-based economic lifestyle. Its generation rate is a function of population and affluence (Hoornweg and Bhoda-Tata 2012) with richer societies characterized by higher rates of waste generation per capita, while less affluent societies generate less waste and tend to practice informal recycling and/or re-use initiatives that reduce the waste per capita to be collected at the municipal level. In Sub-Saharan Africa, about 62 million tonnes of waste is generated annually with an average rate of 0.65 kg/capita/day (Hoornweg and Thomas 1999). In Accra, the correct waste generation rates and its characteristics are non-existent or questionable at best since there has not been any comprehensive waste audit since 1993. Consequently, various sources give conflicting figures: 0.51 kg/day, (MLGRD 1999), 0.41 kg/day (WRI 2007) and 0.81 kg/day (CHF International 2010). Such discrepancies in figures serve as potential impediment to proper planning and this must be taken into consideration in interpreting. Table 2 presents projected municipal waste scenario by 2030.
Table 2 Estimated waste generation of Accra (2000-2030)
The data show increasing waste generation so is the backlog and by inference, unsightly environment. According to Post and Obirih-Opareh (2002), there is a direct relationship between the method of waste collection and environmental sanitation, with residents using the container system clearly disadvantaged, dissatisfied and disappointed. Meanwhile studies have shown that for health reasons, the organic nature of waste in tropical regions like Ghana makes it imperative that it is actually collected daily. This makes the challenges and costs of SWM even more daunting. In Accra, it is generally the city center and the wealthier neighbourhoods that receive service when it is available (see Oteng-Ababio 2010). In poorer areas, uncollected wastes accumulate at roadsides, are burned by residents, or are disposed of in illegal dumps, which blight neighborhoods and harm public health (Huober 2010).
In neighbourhood like James Town, roadside accumulation "has reached levels resembling those that spawned epidemics in European cities 500 years ago" (see EGSSAA 2009: 2; Melara, et al 2013), with its impacts not routinely monitored or virtually ignored. On few occasions where attempts have been made to improve dumpsites management, these often tend to be in reaction to threats of their imminent closure by nearby communities. Unless more effective urban SWM programs and public water supply systems are put in place, outbreaks of cholera, typhoid and plague may become increasingly common.
Waste characterization
Waste composition of any community is influenced by its geographic location, level of economic development, cultural norms, energy sources, and climate, among others. As countries urbanize and population becomes wealthier, consumption of inorganic materials (plastics, paper, aluminum) increases, while the organic fraction decreases. The study examined a number of baseline surveys (see Table 3) to compute the waste composition, since no official data exists. In all instances, proper permission was sought, including appropriate ethical clearance (No ECH 061/13-14) approved by Institute for Statistical, Social and Economic Research (ISSER), University of Ghana, Legon. The findings yielded an average organic component of 67.68%, but the high rate of illegal disposal in drainages, river channels and open spaces raises lots of concern (Oteng-Ababio 2010).
Table 3 Waste characteristics/ Waste stream analysis
Be that as it may, the findings show that with efficient institutional arrangements, political will and appropriate infrastructure investment and human resource, most of the household waste can receive value addition. Unfortunately, until the advent of the project of the Great Thinkers' Club in James Town, separation and treatment of organic waste was very rare. While the recovery and reuse of materials was generally for personal use, there were many 'professional' waste pickers – popularly called 'Kaya bola' in the local parlance, whose activities were seriously threatened by disease organisms, sharp objects and other hazards in the waste. They generally lacked protective equipment – a situation that is a clear manifestation of the extent of poverty in the neighbourhood.
Overview of Great Thinkers' Club activities
Studies (Medina 2005; Sternberg 2013) have noted that the adverse impacts of SWM are best addressed by establishing integrated programs where all types of waste and all facets of the waste management process are considered together. Though desirable, limited resources normally prevent these programs from being implemented, and only a piecemeal solution tend to be possible. The "Great Thinkers' Club" changed this dynamics in the study area by initiating and developing an integrated SWM system and building of the technical, financial, and administrative capacity of the community to manage and sustain it. Suffice to add that whether pursued holistically or in a piecemeal faction, waste managers must ensure that the program is appropriately tailored to local conditions and that the practical environmental, social, economic, and political needs and realities are balanced.
As the waste audit indicated, a large part of household waste in Accra is potentially recyclable as organic waste accounts for about 60%, while paper and other inorganic recyclables (glass, tin) are fairly represented. Yet, this opportunity remains poorly unexplored. Indeed, within the city, a compost plant built in 1976 at Teshie (another suburb of Accra), with a processing capacity of 200 tonnes a day was decommissioned in 2002 due to operational difficulties (see Oteng-Ababio et al. 2013). In particular, lack of source separation of waste greatly affected its operations. Thus, the NGO's activities demonstrate a bold attempt to both tap into the untapped potential embedded in waste and help advance that scholarship in the area of environmental sustainability.
Broadly, the NGO is a youth community-based organisation established in 1999 in Ga Mashie, a suburb with poor sanitation and rising youth unemployment (UN-Habitat 2011). Its mission includes increasing opportunities to enrich and address youth community needs. With a membership of 100, the club's activities span from maintaining efficient environmental sanitation to a recently instituted youth employment through SWM. The funds for the current project, dubbed Youth Engagement in Service delivery (YES) was secured through Co-operative Housing Foundation (CHF) International under the Bill and Melinda Gates Foundation. The project involves a 4-value chain process of municipal waste (biodegradable organic fractions; metals; plastics; electronic waste or e-waste).
The project was initiated with a dual dividend strategy: to engage the beleaguered youth in gainful employment through the provision of environmental services. As part of the project, a house-to-house waste collection, which hitherto was the preserve of only rich neighbourhoods in the city, was introduced at Ga-Mashie in place of the poorly managed container collection system (Kumashie 2011). Using local resources, teams from the local NGO were selected, trained and equipped to provide house-to-house waste collection services to households who willingly agreed to register with the group. Each youth was equipped with a tricycle, nose masks, safety boots, safety overall, and hand gloves (see Figure 3) provided with sponsorship from CHF international (see CHF International 2010). With the exception of the tricycle, all other equipment and training were provided at no cost to participants. The tricycle however was given to participants on a hire-purchase scheme under which each waste collector was to pay cumulatively GH¢600, (US$310), which beneficiaries unanimously agreed to pay in nine months (i.e. GH¢ 63 [US$ 32.57] a month).
Youth team with their tricycles on the house-to-house waste collection operation. Source: Field work, 2013.
The project, which also had a plastic recycling enterprise (Trashy Bags) and a community compost plant, incorporates two rational SWM principles: it encourages source separation of waste and embodies the polluter-pay-principles. At the time of the research, a total of 770 households or 33% of total households in the study area were covered under the project. Each registered household is given two waste bins with which to separate organic and inorganic waste. Each household is also encouraged to separate plastics, waste electrical and electronic equipment (WEEE) and metals. The bins are given for free as a way of motivating participants to undertake source separation of waste (minimise waste), which is seen as the bedrock of any sustainable SWM system. The waste collectors have the responsibility to collect the segregated organic waste daily for onward transfer to the community compost plant.
It is important to add that the quality of compost produced by the YES project was scientifically certified by Ghana Standards Board and has been successfully piloted by some vegetable farmers in Accra (CHF International 2010). Accordingly, the waste behaviour (composition) and the subsequent certification of end-product give a glimmer of hope; the possibility of converting the huge organic waste into compost and thereby, ensuring safer, liveable environment. Its actualization however needs commitment and participation of all stakeholders - government, local authorities, service providers and beneficiaries. Currently, a private company, Zoomlion Ghana Limited, has initiated a waste recycling project; Accra Compost and Recycling Plant Limited. However, the lack of source separation has compelled the company to be very selective in where to pick waste for recycling, (i.e. only high-income areas), where there is little likelihood of waste contamination with fecal matter, which could be as high as 10% (see Kumashie I 2011).
The collection and analysis
The fieldwork involves qualitative data collection that took place between August and November 2012. It consisted of personal observation, focus group discussions (FGDs), and semi-structured interviews with 25 key informants, including the executives of the local NGO, service beneficiaries and participants, 5 community opinion leaders including the assembly man and the leaders of 2 prominent women groups. Some public officials from the Municipal Assembly, Ministries of Local Government and Rural Development, and Gender, Children and Social Welfare as well as a representative of project sponsors were also interviewed. Specifically, the key informants were interrogated on the structure, prospects and challenges of the project, how the transformation of perceived waste into some value and the marketability of the products occurs, and present a more nuanced account of the value chain than the over-simplified end-of-pipe approach. Answers were also sought for the role of the NGO as well as the relationship among the local authorities, the NGO and the local community.
To assess the modus operandi of the NGO, participant observation was employed to learn at first-hand, how the club engages with the community and how it strategizes to outwit the authority's most "preferred" players – formal waste collectors. Two separate FGDs were organized between the beneficiaries and the NGO; and secondly, between the NGO and the representatives of the local authority with the sole aim of gathering in-depth understanding of the structure, processes and human behaviour and the reason governing such behaviour. The FGDs were held in the community, had nine participants each and explored issues bothering on efficiency, power relations and affordability of the services.
Participants discussed the project's challenges, proffered solutions and the possibility of scaling up the project. All submissions were recorded, later transcribed and thematically analyzed. To ensure unrestricted access to the NGO's project sites, their commitment was secured through the well-respected Assemblyman, re-enforced by the intervention of a local sub-chief who happens to be an "environmentalist" and has great passion for a good environment. The study benefitted immensely from earlier works, which engage with the challenges of managing waste in low-income communities (Huober 2010; Matter et al. 2013).
Discussion and evaluation
Tapping the untapped potentials in waste: reflections from James Town
The YES Project waste flow is depicted in Figure 4 and falls in tandem with the government's 'privatization' agenda which, in principle, involves gradually disassociating state-owned enterprises or state-provided services from government control and subsidies, and replacing them with market-driven entities (Grant 2009). In the context of municipal services, the process generally implies reducing local government activity within a given sector by: involving participation from the private sector including NGOS; or reducing government ownership, through divestiture of enterprises to unregulated private ownership, and commercialization of local government agencies.
Schematic Overview of the YES Waste Management System. Source: Author's construct.
In the case of the YES project, which is an example of community participation in SWM, the study shows that each participating household is encouraged to separate both recyclables (either organic, plastics, metals) and non-recyclables. Generally, some of the recyclables (plastics, WEEE, and metals) are sold directly at the household level to prospective itinerant waste buyers who roam the community on daily basis, while the mixed waste and organic materials are collected by the trained community waste pickers for a fee. These service providers haul waste from registered household sources to the composting facility. This is effectively carried out by pre-collection services using the tricycles acquired through the YES project.
According to the system set up by the project and agreed upon by all stakeholders, a household pays between 10p (US$0.05) and GHC 1 (US$0.50) upon a visit by a waste picker depending on the volume of waste available at the time. The waste collector collects (isolates) the organic materials for onward delivery to the compost plant. The waste picker sends collected mixed waste to the transfer stations (mainly communal skips at sanitary sites), where a disposal fee of between GHC1 (US$ 0.50) – GHC2 (US$ 1.00) is paid. During the FGDs, beneficiaries most of whom work in the informal economy, lauded the project's affordability and flexibility "pay-as-you-go" billing system against the formal system which operates a monthly billing option. The NGO has the responsibility of providing a training environment to participants (capacity building) and explain repeatedly the basic concepts and principles upon which the project is founded to the community at large.
The waste value chain: plastics recyclables and compost facility
Results from the waste audit show that since 1993, there have been a gradual reduction in the proportion of organic materials, but a corresponding increase in plastics, increasing from 1.3% in 1993 to 3.5% in 2010 (Oteng-Ababio 2012). The increasing presence of plastics is attributed to the upsurge in the use of polythene bags for take-away food orders and water sachet bags (see Fobil et al. 2005). It is in recognition of this increase that the NGO established a plastic recycling enterprise (Trashy Bags) and trained some of its members to use thin films collected from the community as feedstock to produce handbags, traveling bags, raincoats, jackets, etc (see Figure 5). The study reveals that 'waste' plastics are bought from members at GH¢ 0. 05 for 500 pieces of clean ice cream sachets (250 ml) and GH¢ 0.30p per kilo for empty water sachets (500 ml).
Recycling of thin plastics. Source: Field work, 2013.
Personal observations during the fieldwork confirmed increased presence of plastic waste and how it has been indiscriminately disposed in the drains and other open places. Thus, the move by the project presents positive indicators or economic incentives inherent in thin plastic recycling that the city authority can capitalize on to encourage source separation and minimize the current waste menace. This position was reinforced when it was revealed during the study that 7 new plastic waste purchasing outlets have emerged within the community since the commencement of the project. Indeed, Post and Obirih-Opareh (2002) intimate that most plastic industries operating in the city struggle to get feedstock to meet their installed capacity.
Similarly, the NGO has constructed a community compost plant in the community at the cost of US$22,000 (CHF International 2010). The plant feeds into the employment motivation agenda of the project and creates a synergy between waste collection and disposal. The compost plant operators have also been trained on compost method and facility management as well as occupational safety and health procedures. The facility uses organic waste from the community and the processing of compost normally takes four (4) months (Figure 6).
A compost facility showing the processing of waste into manure. Source: Field work, 2013.
In terms of profitability analysis, waste picking is an informal activity organized on an individual basis and therefore quantifying the actual labour costs incurred to enable one perform proper cost-benefit analysis is quite daunting, if not impossible. However, during the FGDs, participants in the plastic waste chain claim they earn between GH¢ 0.20 and GH¢ 0.35 per kilo or between GH¢ 8.20 and GH¢ 10.20 daily depending on the level of foreign materials (contaminants), which at the upper end, is 95% higher than the national minimum daily wage of GH¢ 5.24. By inference, each participant collects on average in excess of 20 kilos of plastic waste daily, emphasizing the project's potential not only to generate income but more importantly, contributing to a cleaner and healthier environment.
Concerning the compost facility, the challenge participants identified during the study relates to lack of sustained market for the end product. Prior scholarship had identified potential market to include i) real estate developers – using compost as soil conditioner in landscaping; ii) vegetable farmers – for nursing vegetables, and iii) Waste Management Department (WMD) for disposal operations – as capping material to reduce malodors. Meanwhile, at the time the Teshie plant was decommissioned in 2002, the price of a tonne of compost was just GH¢2 (US$1.43)b. After almost a decade, the market price at a private facility (Zoomlion, Ghana Limited) is GH¢30 (US$ 15.5), indicating an increasing opportunity should the question of marketability be resolved (Matter et al. 2013).
On the part of the local government authorities, all respondents from the public service alluded to the fact that the project is a microcosm of what government stands to gain by encouraging community participation in service delivery. They opine that such a process leaves municipal resources available for other equally important urban infrastructure and equipment. The Head of WMD of the assembly asserted, "privatization of such urban services reduces the cost of public services to consumers; relieves the financial and administrative burden on the assembly; increases productivity and efficiency by promoting competition; stimulates the adoption of innovation and new technology; improves the maintenance of equipment; and creates greater responsiveness to cost control measures".
A representative of the local government ministry reveals that community management of service provision as demonstrated by the YES project, is the highest level of community participation, and gives the community authority and control over operation, management and/or maintenance services benefiting its members. He however maintains that such partnership requires institutional support and recognition in order to be successful, which in this case both the Accra Metropolitan Assembly (AMA) and the local government ministry have shown and demonstrated enough commitment.
At the community level, a participant alluded to how the project has ensured a clean environment, as according to him, they could easily identify those who clandestinely litter the environment by the type of waste. An opinion leader also described the project as "important and innovative" emphasizing, "the use of community members to execute community service provides jobs, minimizes crime, poverty, rowdyism and also improves community communication and fosters social acceptability and participation". He called on the local authorities to 'dream' of scaling-up the project into a citywide system than creating new, parallel structures.
Sustainability of YES Project: Is the Youth In Agriculture Project the answer?
The Youth in Agriculture Programme (YIAP), which is a public sector commercial entity, initiated by Ghana government in 2006, seeks to motivate the youth into farming. As part of the incentives, the government provides certain services – land preparation, provision of seedlings, fertilizers, market opportunities, etc. In the 2010 national budget statement, the government declared financial commitment of GH¢2 million (US$1.034 m) mainly for procuring seedlings and fertilizers (MOFA 2012). Given the huge debt the assembly incurs (accumulates) in disposing waste and equally huge funds government commits into procuring organic fertilizers, strategically scaling-up the YES project perhaps, provides an opportunity to address the marketability problem facing the YES compost industry. This is imperative not only because of the paucity of locations for dumpsites, but the possibility of building an engineered landfill anytime soon appears economically a remote possibility. Even in cases where donor support has been secured for such construction, poor planning results in community protestations and resistances (Oteng-Ababio 2010; Owusu et al. 2011).
Meanwhile, critical spatial analysis of the YES chain of activities shows that the city can take advantage of its physical and economic synergies and scale it up, particularly in low-income communities within the metropolis where majority remains severely underserved when it comes to waste management services. Currently, the assembly remains heavily indebted to private service providers, standing at GH¢100 million (US$ 51.7 m) by the end of 2011. Additionally, the disposal chargec of GH¢12 (US$ 6.2) per tonne is an indication of potential cost savings that can accrue to the city if alternative options for value-addition are identified. The YES project has demonstrated that a sizable portion of what is thrown away as "waste" contains valuable resources such as metals, glass, paper and plastics which can be reprocessed as raw materials. Constrained by mounting national debts in the face of many competing needs and tepid economic growth rates, the assembly will continue to bear more responsibility in managing its public affairs with limited resources. Thus, building greater cooperation will not only help manage the 'waste' sustainability but also provide an avenue for job creation and by extension, poverty reduction.
Assuming that the national economic realities are not going to change in the short-term, then it becomes necessary to adopt consumption and waste management practices that reduce the amount of waste destined for disposal or to be discarded. In other words, envisioning waste as a resource will extend the current dump's life, reduce the pressure on areas needed for new dumpsites while at the same time, creates employment. The role of local authorities in this direction is critical and indeed indispensable. Even interventions at household levels also benefit from involving the local authorities, who are the overall entity that have the responsibility for municipal SWM and represent public interest, to enhance legitimacy, support and acceptance or for up-scaling the initiative.
In summation, the study has demonstrated that establishing an integrated SWM system including waste separation at source, resource recovery and composting of organic waste, at least at the local level such as the YES project, requires representation of waste pickers (Kaya bola) and integration of the community to work with all stakeholders, including representatives of waste pickers. It also shows that in such community-led service delivery, local leaders are often active in management or maintain close contact with the municipality or community management body. Additionally, women and teens can play crucial roles, such as initiators, managers, operators, educators, and watchdogs for the community. In other words, encouraging community-based management of service delivery may help address certain social and management problems in SWM – low participation of household, management and operational problems, financial difficulties, and lack of municipal cooperation and capacity building.
The study re-affirms the position that a global depletion of natural resources leads to a global competition for resources and therefore the future competitiveness and vulnerability of cities are dictated by cities' ability to shift to a less resource-intensive production and way of life, with less waste generation and increased recycling (EU 2011). Clearly, there is a compelling need to reduce the volume of waste destined for dumpsites in Accra. The city authorities' apparent addiction to 'landfilling' is damaging for the environment and a manifestation of our failure to see waste as a potential resource. The situation in Accra may not be an isolated case, as most cities countrywide lag behind in terms of policy and practice. The religious enforcement of some 'by-laws' such as the "pay-as-you-dump" policy, which were seemingly enacted without reference to local knowledge, is tantamount to punishing the public. Rather, attempts should be made to give residents incentives to do the right thing and the YES project is a microcosm of such a model.
The project has amply demonstrated that awareness creation amongst all key stakeholder groups, including local government officials, NGOs and the public, is imperative for effective and sustainable SWM services, and that there is a wide range of methods used to raise awareness. It is however, important to choose the communication channels and materials that are appropriate for each target audience and for the specific situation of the municipality. It also building the capacity and adequately equipping participants as waste management, especially landfill operations, is highly technical and normally requires people with specific technical skills and sound scientific background. Bench-marking SWM functions and knowing what expertise is required to perform these functions will assist in drafting appropriate job descriptions and specifications.
By investing and cultivating the interest, enthusiasm and willingness of residents, and adopting acceptable socio-economic initiative-based models that sustainably increase volumes of waste separated at source and recycled, the project has been extremely successful. It demonstrates that putting in place appropriate mechanisms to ensure a reliable and timely waste collection regime and an easy, stress-free, accessible and economical market for recyclables is critical for sustainable SWM system. This is of great importance in Accra, where municipal SWM poses a considerable environmental risk because waste is merely collected and buried with no engineered landfills.
Admittedly, such programmes will not be effective without concurrent community campaigns on the collection and sale of recyclables. Again, the negative preconceptions of city managers and planners about the informal economy in general, play an important inhibiting role in attaining integrated SWM system and this situation needs to be addressed. Seeing informality as a symptom rather than a victim of poor policies and programmes crowds out its inherent potentials, which can be gleaned to ensure sustainable environmental development. Appreciating the waste value chain means that all stakeholders ought to be made part of the governance structure.
Municipal SWM requires planning, foresight and reflexive governance to ensure that sustainable systems are adding value and/or complementary to each other (see Oteng-Ababio 2013). The current situation, where some urban residents are often prevented from participating and benefiting from the development processes and services because of their perceived lack of knowledge, or due to others' lack of knowledge about their situation, conditions and development needs, must be abated. Once knowledge and information is cultivated at the local level, accessed and shared, such tendency can place the community on an equal footing (Veeravatnanond et al. 2012). Such knowledge can be usefully shared between cities, improving prospects for pro-poor investments and development.
Efforts directed towards empirical research must continue, especially regarding waste audits since these will greatly support any future decision by city authorities. It is important to sample other areas to ascertain the possibility of replicating the YES project. In addition, waste separation programme must be accompanied by proper education to create deeper understanding in each community regarding separation, re-using and recycling activities so that the exercise is not simply regarded as tedious one imposed by 'bureaucratic, profit-making government authorities'. Rather, the process will be seen as a new approach that encourages residents to regard waste as a potential resource. The findings resonate with earlier studies (UN-Habitat 2011) that have shown that urbanization of poverty would increase unless the governance structure improve urban planning and management, and recognize the right of urban poor to improve their conditions and participate in the distribution of the benefits that the urbanization process has to offer.
aIn 2012, the exchange rate of a cedi to dollar stood at US$ 0.517.
bIn year 2000, the exchange rate of a cedi to dollar was US$ 0.715.
cThe private contractors charge a disposal fee of GH¢12 per tonne and with no weighing bridges installed at these sites, city authorities are at the mercy of both haulers and managers of the sites.
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Department of Geography and Resource Development, University of Ghana, Legon, Accra, 00233, Ghana
Martin Oteng-Ababio
Correspondence to Martin Oteng-Ababio.
Open Access This article is distributed under the terms of the Creative Commons Attribution 2.0 International License (https://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Oteng-Ababio, M. Rethinking waste as a resource: insights from a low-income community in Accra, Ghana. City Territ Archit 1, 10 (2014). https://doi.org/10.1186/2195-2701-1-10
Environmental sanitation
Waste segregation
Poverty alleviation
Ga- Mashie


ARKit 2 makes it easy to develop vivid augmented reality experiences and enable apps to interact with the real world in entirely new ways. Discover how multiple iOS devices can simultaneously view an AR scene or play multiplayer AR games. Learn about new capabilities for tracking 2D images, and see how to detect known 3D objects like sculptures, toys, and furniture.
Welcome to our session on What's New in ARKit 2. My name is Arsalan, and I am an engineer from ARKit team. Last year, we were really excited to give ARKit in your hands as part of iOS 11 update. ARKit has been deployed to hundreds of millions of devices, making iOS the biggest and most advanced AR platform. ARKit gives you simple to use interface for powerful set of features. We have been truly amazed by what you have created with ARKit so far. So let's see some examples from App Store. Civilisations is an AR app that brings historical artifacts in front of you. You can view them from every angle.
You can also enable x-ray modes to have mode interaction. You can bring them in your backyard, and you can even bring them to life exactly they look like hundreds of years ago.
So this is a great tool to browse historical artifacts. Boulevard AR is an all right app that lets you browse the work of arts in a way that's never been possible before.
You can put them on ground or wall, and you can really go close to them, and you can see all the details. It's just a great way to tell you story of arts.
ARKit is a fun way to educate everyone. Free reverse is an app that places immersive landscape in front of you. You can follow a flow of a river going through landscape and see communities and wild life. You can see how human activity impacts those communities and wildlife by constructions. So it's a great way to educate everyone about keeping the environment green and through sustainable development.
So those were some of the examples. Do check a lot more examples from App Store. So some of you are new to ARKit, so let me give you a quick overview of what ARKit is. Tracking is the core component of ARKit.
It gives you position and orientation of your device in physical world.
It can also track objects such as human faces. Scene understanding enhances tracking by learning more attributes about the environment.
So we can detect horizontal planes such as ground planes or tabletops.
We can also detect vertical planes. So this lets you place your virtual objects in the scene. Scene understanding also learns about lighting conditions in the environment. So you can use lighting to accurately reflect the real environment in your virtual scene. So your objects don't look too bright or too dark. Rendering is what actually a user sees on the device and interacts with the augmented reality scene. So ARKit makes it very easy for you to integrate any rendering engine of your choice. ARKit offers built-in views for SceneKit and SpriteKit. In Xcode, we also have a [inaudible] template for you to quickly get started with your own augmented reality experience.
Note also that Unity and Unreal have integrated full feature set of ARKit into their popular gaming engines. So you have all these rendering technologies available to you to get started with ARKit. So let's see, what is new this year in ARKit 2.
Okay. So we have saving and loading maps that enables powerful new features of persistence and multiuser experiences. We are also giving you environment texturing so you can realistically render your augmented reality scene.
ARKit can now track 2D images in real-time. We are not limited to 2D.
We can also detect 3D objects in a scene. And last, we have some fun enhancements for face tracking. So let's start with saving and loading maps.
Saving and loading maps is part of world tracking. World tracking gives you position and orientation of your device as our six degrees of freedom pose in real world.
This lets you place objects in the scene such as this table and chair you can see in this video.
World tracking also gives you accurate physical scale so you can place your objects up to the correct scale. So your objects don't look too big or too small.
This can also be used to implement accurate measurements, such as the Measure app we saw yesterday. World tracking also gives you 3D feature points so you can, you can, you know some physical structure of the environment, and this can be used to perform [inaudible] to place objects in the scene. In iOS 11.3, we introduced relocalization. This feature lets you restore your tracking state after AR session was interrupted. So this could happen, for example, your app is backgrounded or you're using picture in picture mode on iPad. So relocalization works with a map that is continuously built by world tracking. So the more we move around the environment, the more it is able to extend and learn about different features of the environment. So this map was only available as long as your AR session was alive, but not we are giving this map available to you. In ARKit API, this map is given to you as ARWorldMap object. ARWorldMap represents mapping of physical 3D space, similar to what we see in this, on the visual, on the right. We also know that anchors are important points in physical space. So these are the places where you want to place your virtual objects. So we have also included plain anchors by default in ARWorldMap. Moreover, you can also add your custom anchors to this list since it is mutable list. So you can create your custom anchors in the scene and add them to World Map. For your visualization and debugging, World Map also give you raw feature points and extend, so you know the real physical space you just scanned. More importantly, World Map is a serializable object, so it can be serialized to any data stream of your choice, such as file on local system or to a shared network place. So this ARWorldMap object enable two powerful set of new experiences in ARKit. The first is persistence. So just to show you an example how it works, we have a user starting world tracking, and he places an object in the scene through ARKit hit testing. And before leaves the scene, he will save World Map on the device. So some point, sometime later, the user comes back, and he is able to load the same World Map, and he will find the same augmented reality experience.
So he can repeat this experience as many times he wants, and he will find these objects on the table every time he will start his experience. So this is persistence in world tracking [applause]. Thank you.
[applause] ARWorldMap also enables multiuser experiences.
Now your augmented reality experience is not limited to a single device or single user.
It can be shared with many users. One user can create World Map and share with one or more users. Note that World Map represents a single coordinate system in real world. So what it means that every user will share the same working space. They are able to experience the same augmented reality experience from different point of view.
So this is a great new feature. You can use World Map to enable multiuser games, such as the one we saw yesterday. We can also use ARWorldMap to create multiuser shared educational experiences. Note that we are giving ARWorldMap object in your hands, so you are free to choose any technology to share with every user.
For example, for sharing you can use air drop or multipeer connectivity that relies on local Bluetooth or WiFi connection. So it means that you don't really need an internet connection for this feature to work.
:15 So let's see how ARKit API makes it very easy for you to retrieve and load World Map.
On your AR session object, you will need to call get current world map at any point in time.
This method comes with a completion handler in which it will return you and ARWorldMap object. Note also that it can also return and other in case World Map is not available. So it's important to handle this error in your application code.
So once you have ARWorldMap, you can simply set initial World Map property in world tracking configuration and run your session. Note that this can be dynamically changed as well, so you can also reconfigure AR session by running a new configuration. So once AR session is started with ARWorldMap, it will follow the exact same behavior of relocalization that we introduced in iOS 11.3.
It is important for your experience that relocalization works reliably.
So it is good to, it is important to acquire good World Maps.
Note that you can call get a current world map at any point in time.
So, it's important to scan your physical space from multiple point of views.
So tracking system can really learn about physical structure of the environment.
The environment should be static and well textured so we can learn, extract more features of it and learn more about the environment. And also, it's important to have dense feature points on the map, so it can reliably relocalize. But you don't have to worry about all those points. In ARKit, API really makes things easier for you by giving you WorldMappingStatus on ARFrame. WorldMappingStatus is updated in every ARFrame and can be retrieved by WorldMappingStatus property.
So let's see how this works. So when we start world tracking, WorldMappingStatus will be not available. As soon as we start scanning the physical space, it will be limited. The more we move in the physical world, world tracking will continue to extend the map. And if we have scanned enough physical world from current point of view, WorldMappingStatus will be mapped.
So note that if you point away from a map physical space, WorldMappingStatus may go back to limited. So it will start to learn more about the new environment that we are starting to see. So how you can use WorldMappingStatus in your application code. Let's say you have an app that lets you share your World Map with another user, and you have a shared map button on your user interface.
It's a good practice to disable this button when WorldMappingStatus is not available or limited. And when WorldMappingStatus is extending, you may want to show an activity indicator on UI. So this encourages your end user to continue moving in the physical world and continue scanning it and extending the map, because you need that for relocalization. Once WorldMappingStatus is fully mapped, you may enable your share map button and hide your activity indicator. So this will let your user to share the map. So let's see a demo of saving and loading World Map.
Okay. So can we switch to AR 1. Okay. So for this demo, I have two apps. In one app I will retrieve and save World Map to a local file, and in my second app, I will load the same World Map to restore the same augmented reality experience. So let's start. So as you can see, WorldMappingStatus on top right corner. It was not available.
As soon as I start to move in the environment, it is now extending my World Map.
So if I continue to map and move in this environment, the WorldMappingStatus will go mapped. So it means that it has seen enough features from this point of view for relocalization to work. So it is a good time to retrieve and serialize World Map object. But let's make this augmented reality scene more interesting by placing a custom anchor. So through hit testing, I have created a custom anchor, and I am overlaying this object, basically it's a old TV. I think most of you may have seen in the past. So of course I can still continue mapping the world, and let's save the World Map. So when I saved my World Map, I could also show raw feature points that belongs to this World Map. So those blue dots that you see, they are all part of my World Map. And also as a good practice, I saved a screen shot of my point of view where I saved World Map. So now we have serialized World Map to our file. We can now restore the same augmented reality experience in another app. So let's try that. I will start this app from a different position, and you can see this is my world origin. It is defined on this side of the table, and my world tracking is now in relocalizing state. So this is the same opening relocalization behavior that we introduced in iOS 11.3. So let me point my device to the physical place where I created World Map. So as soon as I point to that same space, it restored my world origin back to where it was, and at the same time it also restored my custom anchor. So I have the exact same AR experience.
Thank you. So now note that I can start this app as many times I want, and it will show me the same experience every time I start.
So this is persistence. And of course, this can be shared with another device.
So back to slides. So this was saving and loading map.
It's a powerful new feature in ARKit 2 that enables persistence and multiuser shared experiences. In ARKit 2, we have faster initialization and plane detection. World tracking is now more robust, and we can detect planes in more difficult environments. Both horizontal and vertical planes have more accurate extent and boundaries, so it means that you can accurately place your objects in the scene.
In iOS 11.3, we introduced continuous autofocus for your augmented reality experiences.
IOS 12 comes with even more optimizations specifically for augmented reality experiences.
We are also introducing 4 by 3 video formats in ARKit. Four by three is a -angle video format that greatly enhances your visualization on iPad because iPad also have 4 by 3 display aspect ratios. Note that 4 by 3 video format will be the default video format in ARKit 2. So all of these enhancements, they will be applied to all existing apps in the App Store except 4 by 3 video format. For that, you will have to build your app with the new STK. So coming back to improving end-user experience, we are introducing environment texturing. So this greatly enhances your rendering for end-user experiences. So let's say your designer have worked really hard to create these virtual objects for you, for your augmented reality scene. This looks really great, but you need to do more for your augmented reality scene. You need to have position and orientation correct in your AR scene so that object really looks like it is placed in the real world.
It is also important to get the scale right so your object is not too big or not too small.
So ARKit helps you by giving you the correct transform in world tracking.
For realistic rendering, it is important to also consider lighting in the environment.
ARKit gives you ambient light estimator that you can use in your rendering to correct the brightness of your objects. So your objects don't look too bright or too dark.
They just blend into the environment. If you are placing your objects on physical surfaces such as horizontal planes, it is also important to add a shadow for the object. So this greatly improves human visual perception.
They can really perceive that objection is on the surface. And last, in case of reflective objects, humans wants to see reflection of the environment from the surface of the virtual objects. So this is what environment texturing enables.
So let's see how this object looks like in an augmented reality scene.
So I created this scene yesterday evening when I was preparing for this presentation.
So while eating those fruits, I also wanted to place this virtual object.
And you can see, it is correct to scale, and you can see more importantly you can see a reflection of the environment in the object. On your right side of this object, you can see this yellow and orange reflection of those fruits on the right, and on the left, you can notice the green texture from the leaves. And in the middle, you can also see reflection of the surface of the bench. So this is enabled by environment texturing in ARKit 2. Thank you.
So environment texturing gathers scene texture information.
Usually it is represented as a cube map, but there are other representations as well.
Environment texture or this cube map can be used as a reflection probe in your rendering engines.
This reflection probe can apply this as texture information onto virtual objects, such as the one we saw in the last slide. So it greatly improves visualization of reflective objects. So let's see how this works in this short video clip.
So ARKit, while running world tracking and scene understanding, continues to learn more about the environment. Using computer vision, it can extract textured information and start to fill this cube map. And this cube map is accurately placed in the scene. Note that this cube map is partially filled, and to set up reflection probes, we need to have a fully completed cube map. To have a fully completed cube map, you will need to scan your full physical space, something like a 360-degree scan you do with your panoramas. But this is not practical for end-users.
So ARKit makes it very easy for you by automatically completing this cube map using advanced machine learning algorithms. Note also that all of this processing happens locally on your device in real-time. So once we have a cube map, we can set up reflection probe and as soon as we place virtual objects in the scene, they start to reflect the real environment. So this was a quick overview of how this environment texturing process works. Let's see how ARKit API makes it very easy for you to enable this feature. So all you have to do in your world tracking configuration to set environment texturing property to automatic and run the session.
So this is as simple as this. AR session will automatically run this environment texturing process in the background and will give you environment texture as an environment probe anchor. AREnvironmentProbeAnchor is an extension of AR anchor, so it means it has a six degrees of freedom position and orientation transform. Moreover, it has a cube map in the form of metal texture.
ARKit also gives you physical extent of the cube map. So this is area of the influence of the reflection probe, and it can be used by rendering agents to correct for parallels.
So such as in case your object is moving in the scene, it will automatically adapt to new position and new texture will be reflected in the environment. Note that this follows same lifecycle as every other anchor such as AR plane anchor or AR image anchor.
Furthermore, it is fully integrated into ARSCNView. So in case you are using SceneKit as your rendering technology, you just need to enable this feature in world tracking configuration. The rest is done automatically by ARSCNView.
Note that for advanced use cases, you may want to place environment probe anchors manually in the scene. So for this, you will need to set environment texturing mode to manual, and then you can create environment probe anchors at your desired position and orientation and add them to AR session object. Note that this only enables you to place the probe anchors in the scene. AR session will automatically update its texture as soon as it gets more information about the environment.
So you may use this mode in case your augmented reality scene has a single object.
You don't want to overload system with too many environment probe anchors.
So let's see a quick demo of environment texturing and see how we can realistically render augmented reality scene. So we can switch to AR 1.
Okay. So for this demo, I am running world tracking configuration without environment texturing feature enabled. So as you can see on the bottom switch controller, it's just using ambient light estimate. And let's place the same object that we have seen before. And you can see it is, it looks okay.
I mean you can see this on the table. You can see the shadow of it, and it looks like a really good AR scene. But what we are missing is that it does not reflect wooden surface of the table. So moreover, if I place something in the scene such as real fruit, we don't see a reflection of it in the virtual object. So let's enable environment texturing and see how it can realistically represent this texture. So as you can see, as soon as I enable environment texturing, the object started to reflect the wooden surface of the table as well as the texture from this banana. Thank you. So this greatly enhances you augmented reality scene.
So it looks as real as possible, as if it is really on the table. Okay. Back to slides.
So this was environment texturing. It's a powerful new feature in ARKit 2 that lets you create your augmented reality scene as realistic as possible.
Now, to continue with the rest of the great new features, I will invite Reinhard on stage.
It's working? Oh, okay, great.
Good morning. My name is Reinhard, and I'm an engineer on the ARKit team.
So next let's talk about image tracking. In iOS 11.3, we introduced image detection as part of world tracking. Image detection searches for known 2D images in the scene. The term detection here implies that these images are static and are therefore not supposed to move. Great examples for such images could be movie posters or paintings in a museum. ARKit will estimate the position and orientation of such an image in six degrees of freedom once an image has been detected.
This pose can be used to trigger content in your rendered scene. As I mentioned earlier, all this is fully integrated world tracking. So all you need to do is set once in your property to set it up. In order to load images to be used for image detection, you made load them from file or use Xcode's asset catalog, which also gives you the detection quality for an image. So image detection is already great, but now in iOS 12, we can do better. So let's talk about image tracking. Image tracking is an extension to image detection with a big advantage that images no longer need to be static and may move. ARKit will now estimate the position and orientation for every frame at 60 frames per second.
This allows you to accurately augment 2D images, say magazines, board games, or pretty much anything that features a real image. And ARKit can also track multiple images simultaneously. By default it only selects 1, but in cases, for example, the cover of a magazine, you may want to keep this set to 1, or in case of a double-page magazine inside a magazine, you want to set this to 2. And in ARKit 2 on iOS 12, we have a brand-new configuration called the AR Image Tracking Configuration that lets you do stand-alone image tracking. So let's see how to set it up. We start by loading a set of reference images, either from file or from the asset catalog. Once I'm done loading such a set of reference images, I use this to set up my session that can be of type world tracking by specifying its detection images property or of type ARImageTrackingConfiguration by specifying the tracking images one. Once I'm done setting up my configuration, I use this to run my session. And just as usual, once the session is running, I'll get an ARFrame at every update. And such and ARFrame will continue an object of type ARImageAnchor, once an image has been detected.
Such an ARImageAnchor is now a trackable object. I can see this by conforming to the AR trackable protocol. This means it [inaudible] is tracked, which informs you about the tracking state of the image. It's true if it's tracked and false otherwise.
It also informs about which image has been detected and where it is by giving me it's position and orientation as a 4 by 4 matrix. So in order to get such image anchors, it all starts by loading images. So that's good.
Let's have a look at what good images could be. This image here could be found in a book for children, and in fact, it works great for image tracking.
It has a lot of distinct visual features. It's we'll textured and shows really good contrast. On the other hand, an image like this, which could also be found in a textbook for kids, is not recommended. It has a lot of repetitive structures, uniform color regions, and a pretty narrow histogram once converted to gray scale. But you don't have to identify these statistics yourself as Xcode is here to help. So if I import these two images to Xcode, I see the sea life one without any warning, which means it's recommended, and the one about the three kids reading showing a warning icon, meaning it's not recommended. If I click this icon, I get a precise description why this image is not recommended to use image tracking.
I get information about the histogram, uniform color regions, as well as the histogram. So once I'm done loading images, I'm left with two choices of configurations. First one is ARWorldTrackingConfiguration.
So let's talk about that. When we use image tracking with world tracking, image anchors are represented in a world coordinates system. This means that image anchors optionally plane anchors. The camera and the world origin itself all appear in the same coordinate system. This makes their interaction very easy and intuitive, and what's new in iOS 12 now images that could previously only be detected can now be tracked.
And we have a new configuration, the ARImageTrackingConfiguration, which performs stand-alone image tracking. This means it's independent from world tracking and does not rely on the motion sensor to perform the tracking.
This means this configuration is not to initialize before it starts to identify images and could also succeed in scenarios in which world tracking fails, such as moving platform like an elevator or a train. I think in this case ARKit would estimate the position and orientation for every frame at 60 frames per second. And implementing this can be done in four simple lines of code. So all you need to do, I create a configuration type ARImageTrackingConfiguration and specify a set of images I'd like to track. In this case, I specified a photo of a cat, a dog, and a bird. I tell the configuration how many images I'd like to track.
In this case, I specified this to be 2. In my use case, I imagined only 2 images will interact but not 3 at the same time. Note that if I'm tracking 2 images and a third comes into its view, it won't be tracked, but it will still get a detection update. And then I use this configuration to run my session.
And as I mentioned earlier, you can also do this using world tracking by simply switching out these two lines. The only difference between image detection and tracking is the maximum number of tracking images. So if you have an app that uses image detection, you could simply add this, recompile, and your app may use tracking.
So in order to show you how easy this really is, let's do a demo in Xcode.
Can we go to AR 2? Yes. So for this demo I'd like to build a AR photo frame, and for this, I brought a photo of my cat from home.
So let's build this using Xcode. So I started by creating a iOS app template using Xcode.
As you can see by now it's pretty empty. Next, I need to specify which image I'd like to attach. For this I imported the photo of my cat, Daisy.
Let's open her up here. That's my cat. I need to specify a name.
I give it the name Daisy, which is the name of my cat, and I specify here the physical width of the image found in the real world, which is my photo frame. I also loaded a movie of my cat.
So let's bring this all together. First, I will create a configuration, which will be a configuration of type ARImageTrackingConfiguration.
I load a set of tracking images from the asset catalog by using the group name photos.
This will contain only one image, which is the photo of my cat, Daisy.
Next, I set up the configuration image tracking by specifying the tracking images property here, and I specify the max number of tracked images that we want. At this point, the app will already start an AR session and provide you with image anchors once an image has been detected.
But let's add some content. I will load the video [inaudible] a AV player from the video by loading it from the resource panel. Now let's add it on top of the real image. So for this, I'm checking whether the anchor is of type image anchor, and I create an SCN plane having the same physical dimension as the image found in the scene. I assign the video player as the texture to my plane, and I start playing my video player. I create an SCN note from geometry, and I counter rotate to match the anchor's coordinate system. So that's it.
This will run. Let's see it live. So once I bring the frame of my cat into the camera's view, the video starts playing, and I can see my cat interact.
Since ARKit estimates position in real-time, I can move my device freely, or I can move the object. So I can really see that there's an update at every frame. Oh, oh, she just left. I guess it's the end of the demo, let's go back to the slides. So as you can see, it's really easy to use image tracking in ARKit.
In fact, it's much harder to make a video of your cat. So image tracking is great at interacting with 2D objects, but we're not limited to plainer 2D objects, so let's talk next about object detection. Object detection can be used to detect known 3D objects in the scene. Just like image detection here, the term detection means that this object needs to be static and can therefore, or should therefore not move.
Great examples of such objects could be exhibits in a museum, certain toys, or household items. And like image detection, objects need to be scanned first using an iOS app running ARKit. For this we offered the full source code of a full-featured iOS app that allows you to scan your own 3D objects. Such objects have a few properties such that they need to be well textured, rigid, and nonreflective.
And they need to have roughly the size of a tabletop. ARKit can be used to estimate the position and orientation of such objects in six degrees of freedom.
And all of this is fully integrated into world tracking. So all you need to do is set one single property to get started with object detection. So let's have a look how it can be set up. I load a set of AR reference images from file or from Xcode asset catalog. I will talk about the reference objects in a second.
Once I'm done loading these reference objects, I used them to set up my configuration of type ARWorldTrackingConfiguration by specifying the detection objects property. When I'm done setting up my configuration, again I run my session with it. And just as image detection, once the AR session is running, I get an ARFrame with every update, and in this case, once an object has been detected in the scene, I will find an AR object anchor as part of my AR frame.
Such an AR object is a simple subclass of AR anchor. So it comes with a transform, which represents its position and orientation and six degrees of freedom as well as it tells me which objects has been detected by giving me a reference to the AR reference object. And implementing this can be done with three simple lines of code. I create a configuration of type ARWorldTrackingConfiguration and specify a set of objects I'd like to detect. In this case, I envision to build a simple AR museum app by detecting an ancient bust and a clay pot.
And I use this to run my session. So in fact, at the office, we build a very simple AR museum app, so let's have a look. So once this bust gets into view of my iOS app, I get a six degrees of freedom pose and can use this to show the scene, very simple infographics floating about the statue. In this case, we have simply added date of birth, the name of this Egyptian queen, which was Nefertiti, but you could add any content that your rendering engine allows you to use. In order to build this app, I had to scan the object first. So let's talk about object scanning.
Object scanning extracts accumulated scene information from the world.
This is very much related to plane estimation in which we use accumulated scene information to estimate the position of a horizontal or vertical plane. In this case, we use this information to gather information about the 3D object. In order to specify which area to look for the object, I just specify a transform and extend in the center.
This is essentially a bounding box around the object just to define where it is in the scene.
Extracted objects are fully supported by Xcode's asset catalog, so it makes it really easy to [inaudible] a new app and reuse them as many times as you want.
And for scanning, we added a new configuration, the ARObjectScanningConfiguration.
But you do not need to go ahead and implement your own scanning app as the full sample code is available for full-featured scanning app called Scanning and Detecting 3D Objects.
So let's have a look how this app works. I start by creating a bounding box around the object of interest, in this case, the statue of Nefertiti.
Note that the bounding box does not need to be really strict around the object.
All we care is that the most important feature points are within its bounds.
When I'm satisfied with the bounding box, I can click press scan, and we start scanning the object. I can see the progress going up and [inaudible] representation indicating how much of the object has been scanned in a spatial manner.
Note that you do not have to scan the object from all sides. For example, if you know that a statue will be facing a wall in a museum, and there is no way that you could detect it from one specific viewpoint, you do not need to scan it from that side.
Once you're satisfied with the scan, you can adjust the center of the extent which corresponds to the origin of the object. The only requirement here is that the center stays within the object's extent. And lastly, the scanning app lets you perform detection tests. So in this case, detection was successful from various viewpoints, which means it's a good scan. And our recommendation here is also to move the object to different location to test whether detection works with different texture and under different lighting conditions. Once you're done scanning, you will obtain an object of type ARReferenceObject, which we have seen earlier in the diagram.
This object can be serialized to usually and AR object file extension type.
It has a name, which will also be visible in your asset catalog as well as the center and the extent used for scanning it. And you will also get all the raw feature points found within the area when you performed your scan. So this was object detection.
Keep in mind, before detection object, you need to scan them, but there is the full source code available for you to download it right now. So let's talk next about face tracking. When we released the iPhone X last year, we added robust face detection and tracking to ARKit. Here, ARKit estimates the position and orientation of a face for every frame at 60 frames per second. Here we can use the, this pose can be used to augment a user's face by adding masks, hats, or replace the full texture of a face. ARKit also provides you with a fitted triangle mesh coming to form of the ARFaceGeometry. This type, the ARFaceGeometry, contains all the information needed to render this facial mesh, and it comes in the form of all vertices, triangles, as well as detection coordinates. The main anchor type of face tracking is ARFaceAnchor, which contains all information needed to perform face tracking. And in order to render such geometry realistically, we added a directional light estimate. Here, ARKit uses your light as a light probe and estimates this ARDirectionLightEstimate, which consists of the light intensity, direction, as well as the color temperature. This estimate will be sufficient to make most apps already look great, but if your app has more sophisticated needs, we also provide the second-degree spherical harmonics coefficients that gather lighting conditions throughout the entire scene for you to make your content even look better.
And ARKit can also track expressions in real-time. These expressions are so-called blend shapes, and there's 50 or more of them. Such a blend shape assume a value between 0 and 1. One means there's full activation.
Zero means there is none. For example, the [inaudible] open coefficient will assume a value close to 1 if I open my mouth and a value close to 0 if I close it.
And this is great to animate your own virtual character. This example here, I've used the jaw open and eye blink left and eye blink right to animate this really simple box face character. But it can do better than that. In fact, when we built an emoji, we used a handful more of such blend shapes. So all the blue bars you see moving here were used to get over the head post to map my facial expressions on the panda bear. Note that ARKit offers everything needed for you to animate your own character just like we did with an emoji. Thank you.
So let's see what's new for face tracking in ARKit 2.
We added gaze tracking that will track the left and the right eye both in six degrees of freedom.
You will find these properties as members of ARFaceAnchor as well as a look-at point, this corresponds to reintersection of the two gaze directions.
You may use this information to animate again your own character or of any other form of input to your app. And there's more. We added support for tongue, which comes in the form of a new blend shape. This blend shape will assume a value of 1 if my tongue is out 0 if not. Again, you could use this to animate your own character or use this as a form of input to your app.
Thank you. So seeing myself sticking my tongue out over and over is a good time for summary. So, what's new in ARKit 2.
Let's have a look. We've seen saving and loading maps, which are powerful new features for persistence and multiuser collaboration. World tracking enhancements simply shows better and fasting plane detection as well as new video formats.
And with environment texturing, we can make the content really look as if it was really in the scene by gathering texture of the scene and applying it as a textured object.
And with image tracking, with image tracking, we are now able to track 2D objects in the form of images. But ARKit can also detect 3D objects.
And for face tracking, we have gaze and tongue. All of this is made available for you in the form of the building blocks of ARKit. In iOS 12, ARKit features five different configurations with two new additions, the ARImageTrackingConfiguration for stand-alone image tracking and the ARObjectScanningConfiguration.
And there's a series of supplementary types used to interact with the AR session.
The ARFrame, the ARCamera, for example. And this got two new additions, the ARReferenceObject for object detection and the ARWorldMap for persistence and multiuser.
And the AR anchors, which represent positions in the real world, the anchor types.
Got two new additions, the ARObjectAnchor and the AREnvironmentProbeAnchor.
I'm really excited to see what you guys will build with all these building blocks in the ARKit available in iOS 12 as of today. There's another real cool session about integrating ARQuickLook into your own application to make your content look simply great. With this, thanks a lot, and enjoy the rest of the conference.


text:
module ApplicationHelper

 def is_active?(link_path)
  if current_page?(link_path)
    "active"
  else
    ""
  end
 end

 def flash_class(type)
   case type
     when :alert
       "alert-danger"
     when :notice
       "alert-success"
     else
       ""
   end
 end

end

redpajama_set_name: RedPajamaGithub