alpha clipping Topic is solved

[slapin]

Hi all! For details in one of my glb models I see that alpha clipping does not work, i.e. I see black or white color where should be nothing. In Blender everything looks fine. I don't want to enable transparency for performance reasons. Is there some way to fix alpha clipping on glb model from code? Thanks a lot for any suggestions.

[sercero]

Hello, what ogre version are you using?

Can you provide screenshots and material definitions?

[paroj]

in meshviewer you can hover the submeshes to highlight them and find the according material name:

you can also play around with the assimp API to find a way to determine the presence of alpha testing.

[slapin]

The above screenshot by @paroj is exactly the one I'd provide as he has my model.
I'd appreciate the example with meddling with materials inside glb. When I export it to Godot it shows ok so glb itself should be fine. With gltf+bin export the result is the same. I need to somehow make the alpha scissoring work with this model as it heavily depends on it.

[slapin]

in meshviewer you can hover the submeshes to highlight them and find the according material name:

you can also play around with the assimp API to find a way to determine the presence of alpha testing.

At current stage of affairs' I'd go with
hardcoding the scissoring but for some reason I was unable to find how yet
Also I don't quite understand at which stage I can meddle with mesh materials so to be sure it uses modified materials and not original ones.

[paroj]

The above screenshot by @paroj is exactly the one I'd provide as he has my model.
I'd appreciate the example with meddling with materials inside glb. When I export it to Godot it shows ok so glb itself should be fine. With gltf+bin export the result is the same. I need to somehow make the alpha scissoring work with this model as it heavily depends on it.

DeepSeek tells me to check for AI_MATKEY_GLTF_ALPHACUTOFF around here:
https://github.com/OGRECave/ogre/blob/e ... r.cpp#L975

[slapin]

Alas, found nothing like that. Also I found no texture transparency even. Only color transparency...

[slapin]

here https://github.com/assimp/assimp/blob/4 ... r.cpp#L284 is code in assimp direct importer and it works (sets material property).

[slapin]

I even bundled custom static version of assimp (the one with debugging added) into OGRE_DIR and it works there,
but the images are still not clipped. So I guess I need to manually change materials at run time, for which I need help how to get material from glb, modify it and put back so Orge will pick it up instead of original material...

[paroj]

what I meant is that the bits on the Ogre side are missing. This should do the job:
https://github.com/OGRECave/ogre/pull/3353

[slapin]

Aw, thanks a lot for this!