pub const UV_CHANNEL: &str = "uv";Expand description
Name of the UV channel: a source channel of 2 values per vertex slot, in
the file’s own convention (glTF’s has v pointing down), interpolated for
new vertices. Read it with crate::Mesh::uvs.
A mesh without it pays nothing. The name lives in the channel namespace;
the plane (u, v) coordinates of a section are plain result fields and do
not meet it.