In advance, I just started to learn TS and Babylon JS, also my English is not good that mean I can only read by translation, so this may be my mistake (Because this problem seems easy to be discovered by other people).
When I use “Mesh.material.emissiveColor” in TS, I got a message that material had no emissiveColor.
So I tried to use this API with native JS, and I found that using this API was completely feasible.
Next, I tried to edit “babylon.module.d.ts” to add emissiveColor property to Meterila. And, compile TS. There were no any problems.
It seems that “babylon.module.d.ts” does not completely contain APIs?