Displacement Maps from ZBrush to Blender
I’m just writing this down here because this is something I hadn’t realized you could do to improve your sculpt renders in Blender and maybe someone will find it useful. There are still many many things I need to learn. Keeping an open mind to learning and improving is something I try to do.
My usual workflow has been to sculpt high detail things in ZBrush, make a copy and then retopologize it using ZRemesher. Then I project the details from the high detail mesh onto this mesh using subdivision levels until it looks the same. After that I export the lowest subdivision level as an .obj file and the highest subdivision level as another .obj file from ZBrush. I then UV map the lowest subdivided model using 3D Coat and bake the details of the highest subdivided model into a normal map. I paint the textures in the paint room and eventually export the UV mapped object with its textures.
After that I can render an image of the completed sculpt in Blender and use the normal map to make the low resolution mesh look like the high resolution mesh. I usually add a subdivision modifier to make it look nice in the render as well.
What I had not realized until last week was that you can also bake out a displacement map for the high detail geometry using ZBrush which can then be applied in a displace modifier in Blender.
Because I had UV mapped my model in 3D Coat I had to re-import that into ZBrush and then project the original high res sculpt detail onto a higher subdivision level of this UV mapped mesh before baking the displacement map so that it would work properly for me. I used multi-map export to make a displacement map exr file and then added this texture in a displace modifier in Blender.
To bake the displacement map this I followed the instructions in this video by Flipped Normals.
The result on the model I tried this with was subtle but noticeable. For this Triceratops model I had sculpted it without going crazy with details anyway because I wanted to add bumpy skin textures using paint effects in 3D Coat.
The details showed up great on the left just with the normal map, however if you look closely you will see the edges of the model on the left are more jagged and not as defined as the one on the right.
The bumps around the head frill look much better on the right with the displace modifier added and the skin creases are more defined. This effect would probably be better if I used a more complicated / detailed model as an example. The effect is more noticeable when textures are not visible.
What I still have to figure out however is how to make the sub surface scattering illusion I briefly talked about show up in my Blender render without having to export it from Sketchfab and re-import it which seems to magically work it out somehow but is now only available to do if I become a Pro subscriber. If I figure that one out I will let you know.
Figured it out here.