from the image on the page you linked, it looks like mapping your videos to a light would be what you want. yes, in real world you'd need a lens, but in 3d, if you want a light to appear that it's coming from behind a cookie, you map an image to its color output (or sometimes its intensity, depending). it's relatively easy to do as far as 'things you can do in maya'... it's just that people don't play with lighting as much as they do modeling so it usually seems 'out of reach' or whatever.
as for why output to image sequence... since i'm working with a PC version of maya i can't speak for quicktime (since it's not one of my render output options) but when rendering out to a .avi file you can experience problems that rendering out to an image sequence can avoid or significantly reduce.
I gather theres no common format that supports video in virtual reality, so that I could share it on my website for instance. However, I have to believe that there must be some kind of format somewhere that I could export those to for my own viewing.
i don't understand what you mean there. i guess i'm asking for a better description of what you want. you showed me a site with an image that appears to be a an art studio/gallery with images projected on the wall.
for a still, honestly, in 3d you would make a box (for polys invert the normals - for nurbs just put the camera inside), then make 3 lights and connect a separate video to each light, point them towards the wall and you're pretty much done.
if you want something interactive i'd recommend making a flash site which uses pre-rendered images you created in 3d or just in flash. using vrml with programs like cortona is kinda iffy, unless you have prior experience with it.
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