Question about animation

Pimpek5555

Hey, I'm new in CG world and there is lots of things for me to learn. I have one question: After animating the base mesh how to project a high poly sculpted detailed model to it? I assume it can be seen only after rendering, yes? 

Mark Dygert

First, it helps to mention what software you are using so people can get specific with details and terms. Otherwise we have to guess, speak generally or list all of the ways you can do things in all of the apps...

Usually the projection is done before the mesh reaches the animation phase, because that could require tweaks to the geometry and proportions of the model and those types of changes can cause a lot of headaches, but it can be dealt with.

Normally the baking would be done on a copy of the model, it doesn't need to be done on the rigged model. You don't want to be doing these operations on the rigged version because it could cause a really dirty history/transforms on the model that will affect animation, so copy it and operate on that copy. This frees you up to not worry about the rigging so you can to take the mesh into other apps and bake textures, paint details, whatever.

If the UV's haven't changed on the low poly then you simply apply the new materials, done!

If UV's changed but topology and geometry didn't change, you can save the UV's from the copied version and load them onto your rigged model.

If the geometry changed a little but didn't cause a significant proportional change that causes you to move the skeleton around, then you can transfer maps (maya) / Render To Texture (max) from one low poly to the other.
OR... 
You can import your new low poly, bind it to the skeleton and transfer/copy the skin weights from the old low poly to the new.

If the proportions of the model changed significantly to the point that you need to move joints around, then you can try to salvage as much as you can using a combination of the above methods but this is a worst case scenario and indicates a failure in the pipeline. It's time to go yell at people and make sure things don't go like this in the future.

Pimpek5555

Thank you for your rich answer. Detailed high poly model I do in Zbrush then retopo it in Maya and continue everything in Maya. You said the projection is done before animation but on every video i've seen people rig and fully animate only base mesh and then they show the rendered results with magicaly projected high poly details sculpted previously on Zbrush (around 10mil polygons). Do you know any tutorials that covers this part? I'm a complete beginner in animation and what seems to be obvious is not obvious for me. 

Mark Dygert

Ahh... I see. Yes generally the baking process take place before rigging and animation. However, animators generally animate with materials set to low quality or off to improve viewport performance. Often Maya and Max don't have the right shader configuration and it's just not important to the motion of the character. Applying the shader and materials is usually done in whatever render engine the person is working in, in the case of games, that is usually a game engine that has a very different shader system than what you are animating in.

TLDR: Bake textures, build the shader/material in the rendering engine.

Here is a tutorial about baking textures inside of zBrush.
https://www.youtube.com/watch?v=Jv9Sz5iQxNU
However you'll need to take those maps that zBrush makes (normal, roughness, color) and build a material in whatever app you choose to do your final rendering. Maya, Max, Blender, Marmoset, Unreal, Unity ect... they all have different ways of setting up materials, do you know which one you plan to use for your render?

Pimpek5555

It seems like complicated stuff. For rendering I plan to use Maya. But I don't want to render with textures and materials. I want a raw render in gray but with my Zbrush high poly model. Sorry for didn't make that clear from the beginning. However, your knowledge is precious and I'll definitely take some notes.