 The background of the scenes in the jungle (a miniature set) were also painted on several layers of glass to convey the illusion of deep and dense jungle foliage.The most difficult task for the special effects crew to achieve was to make live-action footage interact with separately filmed stop-motion animation – to make the interaction between the humans and the creatures of the island seem believable.The most simple of these effects were accomplished by exposing part of the frame, then running the same piece of the film through the camera again by exposing the other part of the frame with a different image.