There are 2 main ways to do stylised wood, a material that could go on a plane or sculpting individual planks and baking it onto a low poly mesh. For this exercise I'm doing the latter.
A big difference I've noticed between modelling for games and modelling for film is, for games you have to optimise so much more - optimisation is king. Because games are played in real time, the engines have to be able to calculate the scene every moment otherwise you get lagging.
So here's the wood I sculpted! I figured style-wise less is more with these planks and didn't do loads of sculpting.
I figured now I zremesh to reduce topology and export it into Maya to UV map, ready for baking. However, I came across a few obstacles and had to decide what was a better workflow and how to optimise most.
1. It doesn't give you nice topology to work with when UV mapping by hand. Edge selection is a lot more complicated and lines drift into one another like a spiral rather than a loop. Also edges don't tend to meet corner to corner like as if you had modelled or hand retopoed it.
Solution: Retopologising by hand is the best solution. But if you really don’t want too, I found ZBrush's auto unwrap to give better results than Maya's auto, it's not perfect but you can easily use Maya's UV tools to improve where the cut lines are and straighten UVs.
2. ZRemeshing softens hard edges.
Problem solving: I thought about creating a displacement map, but that would be completely unnecessary and complicate things if anything, not to mention it would give the engine more to calculate, not less.
* Something new I've learned about optimising textures is that you can pack 3 texture maps into 1 using the RGB channels in Photoshop. I've come across a few names this goes by: ORM (Occlusion in Red, Roughness in Green and Metal in Blue) or occlusion maps or RGB maps or texture channel packing.
Solution: I returned to the block mesh in Maya with the high poly sculpt as a reference and tweaked the low poly by adding in some of the edge cuts I put in when high poly sculpting. This way I could keep the poly count very low AND have the edge cuts actually there (not faked in a normal map). It's a tiny detail but I feel it's important to have to give the planks some sort of character instead of looking all the same. Also this saves time retopologising from scratch.
3. You can't decimate and remesh. For a plank of wood you would only want topology mainly on the edges and not in the middle which decimation would do with messy topology. Zremeshing puts topology all over, not only where it's needed. For a rock or a character's head, zremeshing is perfect because you would want topology all over to hold its form.
Solution to problem 3 was same as problem 2.
Problem Solving: Initially I brought the baked normal map into photoshop to paint. This was very difficult as I couldn't see how exactly this would look on the model. The process of painting, exporting, updating felt very long and tedious.
Solution: I baked the normal map in substance painter but then remove it from the Mesh Maps window where it automatically places it (under Texture Set Settings). Instead create a fill layer and add a mask, turn off all the channels except normal, and plug in the normal map you baked there instead. Now you can mask out the undesired areas of the normal map.
So that's the journey I had learning stylised wood!
To summarise the process:
Step 1: Low poly block mesh in Maya.
Step 2: Sculpt high poly details in ZBrush
Step 3: Add details if necessary to the block mesh edges depending on sculpt.
Step 4: UV map and add ID colours if necessary.
Step 5: Bake the normal and ID map in substance painter.
Step 7: Texture in substance.
If I were doing something like a rock, I would go straight in with the high poly and then retopologise it to create the low poly.
Here's a simple video explaining ID maps and how you use them: https://www.youtube.com/watch?v=kP0pG2PJIqI&t=373s&ab_channel=MichaelWilde
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