Max2Babylon 1.4.2 Multi/Sub-Object transparency bug?

Possible order-of-operations bug?

Transparent parts need to be assigned a separate material from non-transparent parts, otherwise the whole model is assigned alpha blend, which causes sorting errors in the supposedly-opaque parts.

Thus I must use a Multi/Sub-Object material, which assigns the two materials to different sets of triangles in the same model.

If the transparent material uses the first ID in the Multi/Sub-Object material, then the glass is transparent as expected.

However if the non-transparent material uses the first ID, then the glass is not transparent.

I am using one set of textures for my model, because I want both materials to re-use the same albedo+transparency PNG. The transparent material should use RGB for albedo and Alpha for transparency, while the non-transparent material should use the RGB alone only for albedo.

3ds Max 2018.4
Max2Babylon 1.4.2

transp-first_Max (3.2 MB)
albedo-first_Max (2.9 MB) (2.6 MB)

pinging @Drigax to have a look

Thanks for the ping and the repro scenes. I’ll have to take a closer look to figure out what may be causing this, but this definitely seems like a bug.

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