View Full Version : modelled vs. painted detail

02 February 2002, 05:18 AM
hi there, i've got some ideas on 3d modelling techniques, & after noticing all the great character modellers that are posting here, i though this'd be a good place to ask for opinions.

i've seen how efficiently renderman renderers like PRman & entropy (& BMRT even) handle subpixel displacemant, & thought that this could be used as a modelling technique in tandem with poly subdivs. An ideal workflow would be thus:

model general forms as a polygon subdiv control mesh > paint displacement alpha-map in a 3d paint app (deeppaint 3d...) > subdivide & displace at render time...

this means you'd have a light model to rig (with morph displacements for bone rotations ideally) & pose when animating. it could probably be little more than the kind of realtime models used in videogames. you could also bypass the 3d paint bit & use the lo-res nature of the control mesh to ease the unwrapping into a 'paint-shape' for uv-mapping (then just paint the disp. map in p/shop). you wouldn't have the fuss of wrestling with edge loops & other topological headaches when you build a detailed subdiv because you just paint on the detail! folds in cloth, muscle detail, geometry hair...

has anyone got any thoughts on this, perhaps some of you do this already. & if not, why isn't anyone doing this?!

also, i use 3dsmax's polys for modelling, & am trying to get some interconnection with the Entropy demo via Maxman1.7 (eval. licence) with no luck. has anyone tried this combo?

Black Mariah
02 February 2002, 05:02 PM
This is already used to some extent. I remember seeing some pics of the cave troll in LotR where it didn't have the big cracks in it's back because they were a displacement map and it wasn't turned on at the time. It's used a lot more than you think. Using it for major parts of something isn't a good idea because you might not get the deformations exactly as needed. Sure, it would be easier to paint on wrinkles rather than model them, but what about when you need to move them around? The deformations and stretching wouldn't work right. It might be possible in the future for someone to dedicate some time to getting it to work on things like that, but not at the moment.

02 February 2002, 11:28 PM
good point, & another thing would be that the secondary detail can only bump outwards/inwards, so you'd end up with something like an injection-moulded action figure. i know that 3d studio has a thing where you can morph between texture maps as well as geometry- maybe that could be applied to displacements? anyway, i've got some experimentation to do...

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