As suggested in #15105 (comment).
I have never seen a toon shader that supports hotspots, environment maps, or even maps for that matter… Or multiple lights.
A toon shader can be written in a few lines of code, and should not have extended Phong, which is way too flexible. I would have implemented it like MeshMatcapMaterial
.
Alternative opinions, welcome.
As #19609 I am going to implement MMD specific material in
MMDLoader
, so we no longer need to take care MMD for refactoring Toon material.