Is it feasible to make 3D graphics look like claymation?

This is definitely an area I've given some thought to (as I actually enjoy doing claymation/stop-motion animation in the offline world).

I see two major factors that influence the claymation look (on a technical level):

1) The "clay" texture. To reproduce this you'll need to use a shader that has a strong diffusion component. Clay has really no specularity (about as matte as it gets). Just from observation, I've found that rendering using a global illumination technique (like PRT or spherical harmonics or ambient occlusion) seems to give the most "claymation"-like look.

2) The animation. A subtle (and sometimes not so subtle) aspect of claymation (and any stop motion) is that each frame is hand-animated. That means that using all of that nice bone interpolation, etc., that artists take advantage of for most 3D work should be tossed to the side. The ideal scenario would be to have the animator hand animate each frame, and then only use those hand-animated frames (no interpolation). This will likely mean having animation at 10, 12 or 24 frames per second. A way to avoid this would be to take the standard interpolated 3D animation and "perturb" the results of each interpolation a bit.

I seem to remember a paper/video from SIGGRAPH (sometime between 1998-2000) which appeared to be a traditional claymation film (a knight going through a forest and down a river, or something like that), but the "SIGGRAPH" part of it was that it was all CG (I think). If anyone can track that down I'd love to see it again.

I looked into some of this a while back - I'd also like to be able to render 'claymation models.'

One thing to note is that clay models are always very organic - very few flat surfaces. That's obviously not great for your average poly mesh, which is a collection of flat surfaces.

I think you'd be able to achieve something like this with ambient occlusion, like Simagery said. It'd be really cool to see this kind of thing running in realtime on a GPU.

i'd suggest implimenting the M. Oren and S.K. Nayar reflection model. a microfacet diffuse model. it's good for stuff like this. stuff like this could possibly be done with a nice reflection model and some low freuency bump mapping.

check out some of this guys clay stuff. he's got some good stuff.
http://www.3dluvr.com/marcosss/morearni/index.html

Tim

Don't forget the random fingerprints and other clay depressions and movements that happen when the animators get all touchy-feely with the models between frames.

I've also been thinking a little bit about claymation CG recently and I just have one comment (I said I've been thinking a little bit about it, I mean a very little bit [grin]) in response to this...

Quote:

Original post by Simagery 2) The animation. A subtle (and sometimes not so subtle) aspect of claymation (and any stop motion) is that each frame is hand-animated. That means that using all of that nice bone interpolation, etc., that artists take advantage of for most 3D work should be tossed to the side. The ideal scenario would be to have the animator hand animate each frame, and then only use those hand-animated frames (no interpolation). This will likely mean having animation at 10, 12 or 24 frames per second. A way to avoid this would be to take the standard interpolated 3D animation and "perturb" the results of each interpolation a bit.

I wouldn't recommend tossing out interpolation and using set frames in an animation because then the animation will only have those few frames and it would always look exactly the same on every loop of it. What I would do is treat animation exactly the same as usual except only update the model's vertices (or bone matrices in the shader if you're using hardware skinning) at set intervals. That way you aren't seeing the same animation frames over and over and instead it looks more like the animator has moved the model into a new position and that frame's picture taken. Also in tying it all together you would need to update all the model positions at the same time otherwise one model may be updated while another one is staying still and that would take away from the "claymation animator moving everything to it's correct position and snapping the next frame's picture" feel.

Hmm, maybe you meant something similar to that by the "perturbing" interpolation results... I'm not sure.

Anyway, that was from a very brief brain storming and I haven't thought about it too deeply so there may be some problems in there that I'm not aware of. I also don't know too much about claymation techniques so it might be totally wrong. [grin]

Perhaps you could try out some procedural textures to get the "handcrafted" look of those claymation models. With procedural textures you could change the bump-map every interpolation step, so that you get the changing texture of claymation because the animator has to touch those models. Combined with less interpolation steps than usual and a bit of randomness in it (perturberance?), and a good shader for the clay could really look (a bit?) like claymation, I guess.

This guy does some really cool (non-realtime) clay sort of looking art:

http://www.boring3d.com

sam.

Speaking of perturbing vertices... a 'feature' ;) of the MD2 model format is wobbly verticies :)

I'm trying, and failing to find screenshots of Clayfighter 63 1/3 for N64. They may have pulled it off.

Clayfighter, if memory serves, was not 3D... it worked liver Neverhood in that it was all scanned photographs of claymation figures.

It did look cool, though! ;)

Quote:

Original post by izzo This guy does some really cool (non-realtime) clay sort of looking art: http://www.boring3d.com sam.

Wow! This looks so good and inspiring!

Would it not be a good idea to split the whole model down into small hierarchies and replace things rather than animate them?

So rather than have eyebrows move you could replace it totally (like from surprised to sad) or replace the entire mouth with a completely different model. This idea is just a continuation of the other ideas but taking it even further. This way the process would be more like actual claymation.

I've been hearing good things about the Wallace and Gromit game coming out. It's supposed to look pretty good and like the films. It probably won't be as good a representation than the one we're talking about because it is in real-time and they'll need to cheat, but I think they got the material and the lighting right.

I personnally think it is very feasible. However I don't think audience prefers cg art to appear like clay anymore since it is becoming a thing of past projects(chicken run and W&G). Their is alot of technical resources out their that can show you how it is done. Also some User's has already posted some reads about cg clayanimation here.