Cos its hard, thats why.<p>You&#x27;re assuming that CCDs are perfect image sensors that don&#x27;t have noise to cause feature trackers to jitter.<p>You&#x27;re also assuming that sparsely featured objects only need simple back&#x2F;belief propagation to make a good model, finally doing it in less than ten hours on an iphone at anything other than &lt;320voxels^3 is pretty impossible.<p>Even decent commercial laser scanners only have limited resolution at this scale. Your best bet is either lightfield capture or <a href="http:&#x2F;&#x2F;web.media.mit.edu&#x2F;~achoo&#x2F;polar3D&#x2F;camready&#x2F;manuscript_iccv.pdf" rel="nofollow">http:&#x2F;&#x2F;web.media.mit.edu&#x2F;~achoo&#x2F;polar3D&#x2F;camready&#x2F;manuscript_...</a> (which I&#x27;ve not read fully yet, however looks pretty sexy, even if its not very general.)