Baking the Textures
After I'd laid out the UVs for all the low poly pieces I started to bake the textures. I use Xnormal for baking, like a lot of people, and not without reason. I can export my highest level ZBrush sculpt into Xnormal with poly paint data and without any decimation. This way the normal map has all the high poly details as sharp and detailed as they were in ZBrush.
It has a ray distance calculator too so I don't really have to worry about setting up a cage, only for the really complex stuff. So I baked a diffuse map, a normal map and an ambient occlusion map for all my parts.
Texturing Part 2: Texturing After the Bake
I made two PSD files, one for the armor and one for the face, and grouped all my maps inside these. It's easier for me to keep things organized this way. After cleaning up small errors from parts that projected onto each other I started to refine the diffuse map. Xnormal renders out alphas for each piece and they come in very useful when setting up masks in Photoshop. To enhance the diffuse map I baked out a convexity and an ambient occlusion map and applied these on top using different blend modes. I used the red channel from the convexity map; this made the details more noticeable and the AO helped the wrinkles look deeper. On the face I had to color correct the AO because black is not good for skin.
I also created a cavity map in Xnormal with the Generate Cavity From Normal tool. I overlayed this map too, trying different blend modes to get the most detail out of it.
I started to create the other maps necessary. For the specular I desaturated the diffuse and started manipulating it with Curves. I couldn't do the whole specular with only one Curves layer since every material in the map needed to be different, so I used masks to separate everything. The alphas created by Xnormal came in handy for this. I used the Dodge and Burn tool to pop out some parts even more. I also created a gloss map in a similar way to the specular to define the highlights of the materials. I created a translucency map to define where I wanted the subsurface effect to show up on the skin. Lastly I created an emissive map for the glowing parts and an alpha map for the papyrus parts. After all maps were done (Fig.10), I overlayed a grayscale noisy texture with low opacity on top of them to break up the surface.
Rendering in Marmoset Engine
The textures can change according to the lighting so I had to create that first. To get good lighting in Marmoset is actually pretty easy. First I set up a lighting environment. I chose the "Night" preset. This already gave me a good base for my lighting. I wanted the mood to feel underground, inside a cellar or something like that. I adjusted my textures appropriately for the lighting, switching back and forth between Marmoset and Photoshop. I was able to continuously see the changes I was making because I only had to hit Refresh to see the effect.
I added a spotlight with shadows turned on and positioned it to put half of the face in shadow. This helped to make the glowing parts of the armor and face more noticeable. I turned on volumetric fog for the spotlight and added a very simple texture to it. This created the impression that the model is inside a dusty cellar. You can see my lighting setup in Fig.11. After the lighting was done I started to set up the materials.
I find that the two main things that define a skin material are the scatter depth/color and subdermis depth sliders. I desaturated my diffuse map and played with these sliders and colors until I got the look I wanted for the skin. The scatter smoothing setting also helps a lot to make believable skin as it smoothes the hardness out. I applied the translucency map to control the subsurface effect, so it became more visible around the nose and mouth area. I adjusted the specular fresnel too.
The diffuse map was desaturated on this material too; the color comes from the lighting and the specular color. I find the specular sharpness slider is important when setting up a metal material. You can see my material setup in Fig.12.
The only thing left to do was to add post effects. I added ambient occlusion, bloom and adjusted the blue contrast so the whole image became bluer. I also added sharpen to the whole thing.
I didn't do much with the images I got out of Marmoset; just added subtle dust effects with a few brushes in Photoshop (Fig.13).
Thanks for reading this Making Of, I hope you liked it. If you have any questions drop me an email me or leave a comment.