Thoughts on workflow 9-9-08

So I've been teaching myself Zbrush the past few weeks.... its been going ok and I've done some tests with it and Cinema 4d....here's some of my observations...

Zbrush is really good at sculpting fine detail and creating organic forms that would be impossible to replicate in a non 3d sculpting app... Zbrush and Mudbox are the only two I know of...

On the other hand to create the fine detail the Zbrush object get really high poly like 3 million polys+

Its not practical for me to use such a high poly model inside Cinema 4d for animation....

I really love painting my models in Bodypaint... Bodypaint DIES when trying to work with these mega million Zbrush models even on my mega machine...

Zbrush can be used to output a low poly model and a displacement map so that all the fine detail from the millionpoly model can be added at render time... So far I haven't gotten this to work correctly.... BUT even if it did work I would have to paint on the displaced model which can be done with Bodypaints Raybrush mode... but with such a fine SPD map the process lags...

To do facial animation you either need to use bones or morphs or a combination of both.... To create morphs you need to push around a models points... again... with millions of polys/points this is almost impossible.... So you saw lets use the low poly model from Zbrush to do it... that would work as long as the displacement map only contains fine detail... if there's any larger displacement your going to have no way to preview what the morph it doing other than rendering a frame every time you can to see it.... If read about some plugins that show displacement in the Cinema 4d viewport but again...I need to go for speed and stability....

It seems the popular way to do facial morphs in Cinema 4d is to manipulate the points of your model while it is inside a hypernurbs object so that you can work with a low poly geometry and see the higher res results in the viewport in realtime...

So at this point it seems the best way for me to integrate Zbrush into my workflow is to....

Sculpt non-animated organic content to be integrated into C4d scenes...
Sculpt high poly non-animated organic content for use in Close-up/Extreme close-up shots in Cinema 4d scenes...
Add fine detail to low poly characters with SPD via displacement maps...
There are A LOT of kinks in geting Zbrush--->Cinema 4d and back when using low poly models and DP maps for char animation....

Sub-polygon displacement is the key though.... I need to utilize it to the MAX.... It relies heavily on the CPU and available RAM... So my plan is to use as low poly models as possible to capture the form I'm going for with speedy animation and push SPD as far as it can go with my available memory (8gb) .....

back to the computers....

Comments

  1. hiya, spanish fan here ;) try softimage, zbrush integration, bodypaint, face robot...

    ReplyDelete
  2. ...sounds rather complicated to me...you sure you want to slow down your workflow like that?

    If going this high poly destroys the M dot Machine, maybe thats a sign that you should keep ZBrush intergration minimal, or at least tone down the levels a bit before exporting.

    I dunno...Im just doing stick figures... xD

    ReplyDelete
  3. Gnarly problem, mdot. Zbrush integration sounds like a pain. I hope it doesn't distract you too much. Suggestion for low-rent facial animation: Crazy Talk by Reallusion. You can green screen everything but the face, animate in real-time in CT, then composite and motion track the face over the original. It actually looks pretty good. Save you a hella time.

    Thanks for sharing all of your problems and thoughts about your work. One of the reasons I tune in every day.

    ReplyDelete
  4. I've played around a bit with ZBrush myself. I'd expect the real problems with displacement come when you have a low-poly and high-poly model that are very different -- meaning that you need to use high displacements. If you have high- and low-res models that are fairly close together, the effects of displacement should be reasonably predictable while animating.

    I've noticed that ZBrush encourages you to simply subdivide when the part of the model you are working on is too coarse to hold the details you are sculpting, which leads to a model that is subdivided in places that don't need it. It's hard to pick any particular subdivision level as your exported coarse mesh, then, because one part of the model needs it coarse for animating while another needs it fine to minimize the amount of displacement.

    ZBrush 3 added a retopologization function that lets you create a new polygon topology on top of the high-res mesh... effectively giving you a decent low-res mesh like you would have gotten in a low-poly modeler, so you can get the appropriate amount of detail into different parts of your model. It seems like a lot of extra work, though, and I'm not totally sold on the interface, yet.

    Have you tried painting the model directly in ZBrush? It's quite good at painting high-res meshes, once you get past the somewhat unintuitive interface. You'll probably want to do your UVs in another program, though.

    ReplyDelete
  5. I looked into FAcerobot and Crazytalk... thanks for mentioning them!

    JCL

    Yeh I think i was trying to push the meshes too far when using the DP map exports... i tried some smaller detail DP maps and it worked pretty good BUT yeh your right it kinda sucks that you can't control where the displacement will occur... cause yeh you have to subdivide a couple times to sculpt the detail but then you export the map the whole model is affected... I tried painting textures in Zbrush the other night and your right it was kind cool... I looked into retopologizing...seems interesting but might be a bit too much work for me to do on all the models I have to create... I'm giving myself till the end of the month to up my Zbrush skills then I'll figure out how it will work best in my workflow... thanks for the insight.

    ReplyDelete

Post a Comment