Displacement Mapping inside Vray Blend Base Material - Broken in 2.20+

[jdrouse]

A VRay Material with displacement as the base material of a VRay Blend Mat correctly displaces in 2.10. However, displacement does not occur in 2.20+.

Repo:
0.) Use Vray 2.20/2.30 for broken disp.
1.) Create VrayMat + Noise displacement in slot
2.) Render with working displacement.
3.) Create VrayBlendMtl and add original mat to Base Mat slot.
4.) Render with broken displacement.

Try again in Vray 2.10. correctly working.

-John

[Zdravko]

We tested a simple scene, with that set-up, with both V-Ray 2.20 and V-Ray 2.30 versions. But we couldn't reproduce the issue in here.
Which exact V-Ray version are you using (official or nightly)?
Could you attach a simple scene?

[vlado]

Actually I can reproduce this here; will fix it, but in the meantime, you can add a VRayDisplacementMod modifier to the object; turn on "Use object mtl" and turn on "Relative to bbox" if needed.

Best regards,
Vlado

[jdrouse]

Thank you! This work around will take care of our immediate problem. Happy to have identify the bug.
-John