(This question is still unanswered, though I got some helpful information about how Sketchfab thinks. Any answers would be greatly appreciated!)
I struggled for much of the weekend with trying to give Sketchfab what it expects in its Blender exporter with regards to alpha clipping/transparency, but seemingly exhausted all of my options without luck. First, here's the effect I'm trying to achieve:
As you can see, the image in the background is transparent around the characters, and importantly, the shadow below them is partially transparent. This image billboard was just a simplistic test before I attempted to do something similar on my characters, but I haven't found a solution.
To achieve this effect I need to do the following settings in Sketchfab itself:
As you can see, it uses "Alpha Blending", points to the alpha texture, and bases the alpha on luminance. Unfortunately, this must all be done manually every time I upload. Now, here's the Blender setup that I thought would be closest to Sketchfab's exporter expectations, though I tried many other things:
The alpha texture affects the alpha channel of the texture. The color texture only affects the color channel. Things look great in Blender's GLSL real-time rendering, and Sketchfab's docs say it should support most GLSL features.
Am I going about this in the wrong way? What exactly does Sketchfab's exporter in Blender expect for alpha?
- How do I set things up in Blender so that it exports using "Alpha Blending"?
- How do I get it to base it on luminance?
- How do I get it to know to set my alpha texture to the one I set in Blender?
- How do I get it to use "Alpha Masking" if I wish to do that? Is there a way to differentiate between the two?
Thanks so much for your help.
On a side note, I cannot tag this with Blender or Alpha? I cannot add any tags at all. Weird.