Displacement material order bug

[Under-J]

Issue

Displacement isn't working as expected when using multiple materials, each with its own displacement, on an object.

Steps to Reproduce

1. Put a material with displacement on one face of an object.
2. Put another material with a different displacement on another face.
3. Activate Displacement in the Material tab.
4. See the render.

System Setup (Environment)

RTX 3060 12GB, i5-10400, Windows 11, Blender 3.5.

Detailed Description

Make it match Cycles.

Cycles, expected results:

RPR results show that the first displacement item in the Active Material overrides all other displacements. If you rearrange the order of the materials, it affects the displacement of the entire object, including faces without material or with blank material:

When the Checkerboard texture displacement is first in the Active Material Index, every face is rendered with checkerboard displacement:

When the Diagonal texture displacement is first in the Active Material Index, every face is rendered with diagonal displacement:

When the Dots texture displacement is first in the Active Material Index, every face is rendered with dots displacement:

Disp Bug.zip

[ARozghon]

thank you for the request, will investigate it

[odil24]

@ARozghon @bsavery I accepted that does not working as expected also in latest v3.6.7