Tutorial: Transitional Meshes for Real-Time Faces

Vadim Sorici has shared a new guide to working with transitional meshes with the help of ZBrush, Substance Painter and Toolbag. The guide is great for artists working with eyes and teeth. 

Transitional meshes are quite important to glue together/blend two separate objects. For example — eyeballs to eyelids, teeth to gums. In this tutorial, I’ll show the workflow that will be applicable to the eyes and teeth.

1.Combine face/eye mesh, place geometry that connects the eye and eyelids. Make sure the mesh is floating above a little bit, and there are no overlaps with eyes and eyelids. This would be our low-poly mesh that we’ll use later for baking and rendering in Marmoset. Make sure to UV it.

2.Let’s analyze the eyes – aside of the blur and occlusion between the eyes and eyelids, there’s also a thin strip of tear fluid – upper and lower tear menisci, these fluids create subtle highlights, that really sell the eyes and add to the realism.

3.As you can see, since the mesh we use is concave, the highlight is weak and wrong. We need to bake normal map of convex geometry on the concave transitional mesh to get proper highlights.

4.You can model a tube in Maya, or any other software. In my case, I like to combine all the geometry and dynamesh it in ZBrush, which might be an overkill, since just having a tube should be enough for a good result. The goal is basically to model/sculpt the fluid. You’re free to experiment and see what works best for you! Export it, this will be the high-poly that will be baked on the transitional mesh.

5.Bake the highpoly to lowpoly. It should look like this. You can see the normal map giving proper highlight now.

6.Now let’s place the eyes and face only as our highpoly, and transitional mesh as lowpoly. Import the base textures, bake the color map and AO. We will need these maps in the future.

7.Once all the maps are baked – let’s jump in Substance Painter. In Substance Painter, we’ll be able to paint the mask, and blur the textures manually and in an iterative manner. The mask is essentially dictating what area is going to be blurred and dithered.

8.Once in substance, begin with mask painting in the opacity channel. Then play around with the blur amount and a desired amount of AO between the eye and eyelids. Export the textures. Jump into Marmoset.

9.Add meshes to Marmoset, apply NM, go to Transparency tab, choose Refraction/Dither, use setting as shown on the screenshot. Latest Marmoset has dithering added to the Refraction, this way we can blur an area, but also mask the dithering. Be mindful that Gloss slider controls the blurriness. Previous versions of Marmoset don’t have Dithering for Refraction. In this case, using Texture Blur+Dither is better and cheaper.

10.Side to side comparison

Vadim Sorici

Make sure to check out the artist’s portfolio here.