Order independent transparency Bugs with bump texture and rendering pipeline

Hi There,

we are having two issues with Order independent transparency in Babylon 5.1.0.
Both happen when OIT is set to true.

  1. When a rendering pipeline is created with the hdr flag set to true, the sorting of the transparent objects break (the front side disappears).

  2. When a material with a bump texture is rendered, wireframe like artifacts appear on the material.

We created this playground for reproduction:

Every help, hint or fix is appreciated :slight_smile:

Best regards,
Phil

cc @CraigFeldspar

Bump bump @CraigFeldspar

There is indeed a bug with bump + OIT that comes from shader derivatives (dfdx and dfdy) being equal to 0, probably because some code paths from OIT don’t reach the derivative calculation. I’m still looking for a proper way to fix it, as safeguarding dfdx values has proven to be breaking bump.
In the meantime, I would advise to either disable bump or disable OIT, whichever is less important visually in your case

Keep you in touch,
Ben

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