Custom Normals Addon
This addon is a set of tools to help author Custom Vertex Normals for clean Toon/Cel Shading. The focus of this toolset is to help author Normals for 3D Anime characters, but can help improve Normals for any application. Typical realistic asset workflows tend to use a high poly mesh and then bake Normals from it to a low poly version. This method is good for preserving surface detail and is well supported by many toolsets. But in anime and other stylized rendering, the goal is generally to reduce and smooth surface detail instead. And the typical method relies on having a high poly version in the first place, which is often not the case for stylized character workflows.
These tools help make it possible to author high quality Normals with a game quality mesh as the starting point. They can be used directly as Custom Vertex Normals if there is sufficient vertex density, or the mesh can be subdivided and the Normals baked to a Normal map following the usual methods.
This page will summarize what problems are being addressed by the tools conceptually. Usage and Technical Details are described on the pages for each component.
Components
Laplacian Smooth Normals Modifier
The purpose of this Modifier is to make triangles and topology spacing not matter for shading. It has the option to Invert typical Face Area Weights and thus compensate for differences in face sizes. And the Laplacian Smoothing is topology independent, allowing proper Normal Smoothing to reduce detail and complexity even if the mesh is uneven. In short, you get the same results as a clean quad mesh even if your mesh is a mess, and you can smooth it! No more worrying about triangles messing up the shading!
This is a Modifier built with Geometry Nodes. The addon allows for a live preview of the Custom Normals without having to set up Geometry Nodes Attributes in the materials. And the option to set them on the mesh without actually applying the modifier, which is convenient for meshes with shape keys.
Adjustable Anime Face Proxy Mesh (coming soon)
Stylized characters don’t just need their shading to be clean, they need it to be the right stylistic shape. This often means that the shading shapes you need are not actually those your geometry will produce. In places like anime character faces, the shading needs to be that of a much simpler surface. The solution is to use a separate proxy mesh that is the correct shape and transfer Normals from it. This works well but introduces many new problems, like getting a good transfer without gaps between the meshes causing artifacts. If you fit the proxy to the face cleanly enough to avoid these problems, then it won’t be the right shape. If it is the right shape, you won’t get a good transfer. So you actually need a copy of the proxy mesh in the correct shape, and another with the correct fit, and it all quickly gets complicated.
This is an optimized, adjustable proxy mesh. It comes with a rig to conveniently fit it to your character’s face (line up a few points like chin, ears, and brow.) And then Geometry Nodes takes care of all the transfer issues and other complexity under the hood. There are also options to customize the shape, transfer a UV map, and more.
More info coming soon.