Need help understanding colors in manifold.

[briansturgill]

1. Am I correct in believing there is not 2d color support?

2. You appear to be putting colors in the second 3 floats in vert_properties. (The first three being vertices).
   This appears to be coloring vertices.
   I would have though one would color faces.
   What is the color of a face that has 3 different colored vertices?
   Clearly I've got something wrong here, I'd appreciate help understanding how it works.

[elalish]

Manifold doesn't support colors, it supports arbitrary vertex properties. CrossSection does not yet support properties.

We use vertex properties because they are a lot more general than face properties: vertex colors, vertex normals, UV coordinates, bone weights, etc. It is standard practice in graphics to interpolate all of these properties across triangles, and these properties are defined for most commonly-used triangle formats like glTF. ManifoldCAD.org is designed to make glTF/3MF authoring easy, so it is more opinionated about what properties go where.