Face Proxy Tips & FAQs

Frequently Asked Questions

Can I use the Laplacian Smooth on the Proxy Normals?

Yes. This is the default behavior. The addon will create a Laplacian Smooth modifier after the Proxy Normals modifier. This can smooth things out, and also help blur the Proxy and regular mesh Normals together at the boundary.

What happens below and above the curves? They only go from the chin to the brow.

The setup actually creates another curve profile above and below to help define the transfer space. These curves have Normals pointing straight up and down, which means that they are effectively spherical Normals. But this area is actually hidden because the Auto Boundary Mask mixes to the actual mesh Normals in the same area, overwriting them. For now there is no option within the setup to set arbitrary Normals for those curves, but you can disable the Auto Boundary Mask, or use the Radial Normals mask to paint those in. In future versions there will be more options to choose the number of Curves and their placement.

I can't get the area around the jaw line to look good. How do I get a smooth shape without jaggedness in the shading?

The Proxy Normals don't actually define the jawline curve. They blend into the actual mesh Normals by default. This area is very difficult to get right because the amount of curvature amplifies problems related to vertex density, face shape, and triangulation (see explanation in the introduction at the top.) Generally, it can be improved by adding more loops along the jawline (like a bevel) to support the curvature. Make sure triangles are crossing quad faces in the correct direction: towards the center and down, matching the likely angle of the shading terminator. Laplacian Smooth also helps. Or remove the jawline curvature entirely by masking to Radial Normals or making your own Boundary Mask. The Jawline is such a difficult area that we are planning a whole section of the tool just to help get it right.

The shading looks good, but it does not match up with shading on the rest of the character. The shading terminator on the hair doesn't line up with the face.

There are many ways for the Proxy Normals to look good, but be creating a shape that is too different from the actual face shape. Generally this will not happen as long as the handles are roughly the same length, as that gives cylindrical shading across the face. If you are having this problem, first check the base shading of the face and see how it lines up with the Proxy shading. Then adjust the proxy handle lengths to move it over until it lines up better.

I can get the shading to look good from the front, but the side seems wrong. If I fix that, then the front looks wrong.

This is a fundamental problem with 3D anime shading. 2D anime and manga draws front and profile shading in a way that is visually pleasing but usually physically inaccurate. General speaking, you cannot get both the front and side to match these styles with the same surface shape. And there are similar problems with how eyes and mouths are drawn from different angles. The correct solution is camera view angle based automatic correction, which is an intended feature (but will not export to game engines unless built there too of course). Until that is implemented, posing or shape keys can be used to correct the shading for different angles.

My character uses game-style hollow anime eyes. The toon shading does not look good in the eye sockets.

This is because of the difference in depth of the eye sockets. If the character is viewed directly from the front, and if the projection space was straight forward instead of radial, then it would work correctly, but be even more wrong from side angles. This is another problem that needs correction based on the camera angle. We will attempt to solve it in future versions. For now, correct for different camera angles with posing or shape keys, or just keep the eye socket shadeless like on our demo character pictured in these docs (did you notice?)

How do I add details like a nose shadow or rembrandt triangle?

These are not currently supported, but can still be added the same way you would to other setups. Some details can be restored from the base mesh with masking. Or details can be added with Bump or Normal Map textures. Supporting a detail decal system is planned for the future.

My character has a more complex face with more detail and planar features like ArcSystems or JoJo. Will this setup work for those faces?

Not yet, as there are not enough curves or controls to define more complex faces, especially chiseled male faces. That requires more curves, more points, and per-point control of things like influence, radius, falloff, and interpolation shape. These things are all technically possible, and we hope to develop this tool to that point that it can handle such advanced subjects.

How do I mix these with existing Custom Vertex Normals, or other Attribute Normals from a different Geometry Nodes modifier.

Geometry Nodes has no way to input existing Custom Vertex Normals until 4.5, so that cannot be done at this time, but soon. Mixing with other Attribute Normals created in Geometry Nodes can be easily done by inserting a modifier after the Face Proxy Normals but before the Laplacian Modifier if you want to change them before Smoothing, or after the Laplacian Modifier if you want to mix or alter the smoothed version. The Addon and Debug material use the attribute named _GN_Custom_Normals, so as long as your setup still writes to that in the end, everything should work fine.