Add support for multiple diffuse textures.

[ttvd]

We only extract the first diffuse texture ogl_tex# . We would like to add support for multiple diffuse textures with blending between them.

• Support multiple diffuse textures, blending.
  • Support retrieving number of textures through (ogl_numtex, int)
  • Retrieving individual diffuse textures through ogl_tex# to retrieve.

Filed as RFE: #74207 : Unreal: Add support for multiple diffuse textures.

[ttvd]

Related to #6