Bug Rh9 Raytraced ignores "By Parent" material, uses layer instead

[AlanMattano (Soaring Stars lab)]

AM57-58

AM 24 06 57-58 2 Rh9 RaytracedMaterial.3dm (3.0 MB)

Hello,

While creating this glider vario, I discovered several issues that I’ve isolated in the attached Rhino file. I believe there are two related bugs in Rh9 WIP (9.0.25343.14055, 2025-12-09) with material assignment inconsistencies between Raytraced and Rendered viewports.

Bug 1: Inconsistency between Raytraced and Rendered viewports.
A polysurface shows different materials in Raytraced (uses layer material) versus Rendered (shows manually assigned materials correctly).

Bug 2: Raytraced ignores “By Parent” material assignment.
Object Properties set to Material > By Parent, but Raytraced uses layer material instead. This suggests a missing integration between object-assigned materials and Properties settings.

Video demonstration for Rhino Team: https://youtu.be/bAi0ry0SLV0

Thanks for investigating.

[Japhy]

Hi Alan, Thanks for reporting and providing the example.

RH-91045 Inconsistency between Raytraced and Rendered viewports

RH-91046 Raytraced ignores “By Parent” material assignment.

[Gijs (Gijs de Zwart)]

not sure if the latter is a bug. AFAIK by parent is only for block instances. Here’s an example what happens:

materials-blockinstances.3dm (3.1 MB)