Working on a Blender (collada) export, need some help

[Roland Melkert]

Well I've been tweaking on the glTF export this week and discovered why textures didn't work.

A glTF export from LDCad 1.7 Alpha 2 into Belender gives this:

  alpha2.jpg (Size: 28.29 KB / Downloads: 46)


An improvement over the Alpha 1 version but not what I wanted.

The problem is textures in LDraw are basically stickers you put on a part of the mesh.

glTF does not support that it basically assumes textures are wallpapers. Pre blending the images isn't good ether as it will give you this:
   


Next I decided to try and fix the issue inside Blender to see what a export to glTF would generate.

The texture material from the LDCad export generates this for the blender material.
   


The only way to get what I want is to manually change the shader into something like this:
   

edit: Bit shorter by avoiding the extra shaders (still not preserved in a export)
   

But when you export this to glTF in blender it will loose the background color again 

I'm not sure this is a blender (export plugin) thing or a general glTF issue.

Anyone know of a way to get the above result using valid glTF2 ?

Or should I just abandon the idea and maybe try another format. USD seems promising, but I'm not very motivated to start writing a (4th) exporter from scratch