Loss of Something on conversion

[yunze89]

We had a some issues on conversion. (see below images and descriptions)

1. It seems that the surface of button is somehow partially gone.
(The number of triangles is not changed, while the number of vertecies is decreased 1,088,424 to 264,382 on conversion)

obj-original

gltf

2. It seems that the unnecessary plane has added.
(the number of vertecies is decreased too)

obj-original

gltf

I don't know if these 2 problems are related to issue #235, #212 or #204. still occured in v3.1.0

**3. The RGB color applied on grey scale texture image is missing on conversion. See below the material definitions in .mtl and the texture image.

newmtl PT_FABRIC_FRONT_1322893
Ka 0.230915 0.199538 0.173866
Kd 0.898039 0.776013 0.676173
Ks 0.025778 0.025778 0.025778
Ns 5.000000
illum 2
d 1.000000
map_Ka 2.3mm_3_Edit.png
map_Kd 2.3mm_3_Edit.png

2.3mm_3_Edit.png

left obj-original / right gltf

If You need these obj files, I can email it to You! : ) Thanks!