GPU No Ground Shadow with OpenGL (Bug?)

Serengeti (Rhino WIP)
1

Hi,

It seems that ground shadow does not appear using OpenGL in ‘Show shadows only’ mode However, it does work in ‘Use a material’ mode and works for both modes using the Direct3D technology.

Thanks

Rhino 9 SR0 2026-2-3 (Rhino WIP, 9.0.26034.12305, Git hash:master @ f10eb7a75f4fc041d932b4ee5c7a6367183ae4eb)
License type: Commercial, build 2026-02-03
License details: Cloud Zoo
Expires on: 2026-03-20

Windows 11 (10.0.26200 SR0.0) or greater (Physical RAM: 32GB)
.NET 9.0.12

Computer platform: LAPTOP - Unplugged [47% battery remaining]

Hybrid graphics configuration using OpenGL
Primary display: Intel(R) Iris(R) Xe Graphics (Intel) Memory: 2GB, Driver date: 12-1-2025 (M-D-Y).

Integrated graphics device with 4 adapter port(s)

  • Windows Main Display is laptop’s integrated screen or built-in port
    Primary OpenGL: NVIDIA RTX A1000 Laptop GPU (NVidia) Memory: 4GB, Driver date: 10-29-2025 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 581.80

Integrated accelerated graphics device (shares primary device ports)

  • Laptop’s primary display device

OpenGL Settings
Safe mode: Off
Use accelerated hardware modes: On
GPU Tessellation is: On
Redraw scene when viewports are exposed: On
Graphics level being used: OpenGL 4.6 (primary GPU’s maximum)

Anti-alias mode: 8x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: High

Vendor Name: NVIDIA Corporation
Render version: 4.6
Shading Language: 4.60 NVIDIA
Driver Date: 10-29-2025
Driver Version: 32.0.15.8180
Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24 bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 4 GB

OpenBLAS: OpenBLAS 0.3.30 DYNAMIC_ARCH NO_AFFINITY Haswell MAX_THREADS=64.

Rhino plugins that do not ship with Rhino
C:\Program Files\Common Files\McNeel\Rhinoceros\7.0\Plug-ins\KeyShotRhinoPlugin (78243fe3-17a0-4865-b713-88b4c224c48c)\1.5.0.0\KeyShotRhinoPlugin\KeyShotRhinoPlugin.rhp “KeyShotRhinoPlugin” 1.0.0.0

Rhino plugins that ship with Rhino
C:\Program Files\Rhino 9 WIP\Plug-ins\Commands.rhp “Commands” 9.0.26034.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\WebBrowser.rhp “WebBrowser”
C:\Program Files\Rhino 9 WIP\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoScript.rhp “RhinoScript”
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoBonusTools.rhp “Rhino Bonus Tools”
C:\Program Files\Rhino 9 WIP\Plug-ins\IdleProcessor.rhp “IdleProcessor”
C:\Program Files\Rhino 9 WIP\Plug-ins\UpdatesAndStatistics\UpdatesAndStatistics.rhp “UpdatesAndStatistics” 9.0.26034.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 9.0.26034.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 9.0.26034.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 9 WIP\Plug-ins\MeshCommands.rhp “MeshCommands” 9.0.26034.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\RhinoCycles.rhp “RhinoCycles” 9.0.26034.12305
C:\Program Files\Rhino 9 WIP\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 9 WIP\Plug-ins\Displacement.rhp “Displacement”
C:\Program Files\Rhino 9 WIP\Plug-ins\Calc.rhp “Calc”
C:\Program Files\Rhino 9 WIP\Plug-ins\SectionTools.rhp “SectionTools”

Display issue.3dm (2.9 MB)

2

Hi Sach -

This is what I see when I open your file:

image
image764×444 27.2 KB

I take it you are seeing something else?
-wim

3

The ground shadow doesn’t show at my end with OpenGL in WIP
The same model in R8 works as expected – with the shadow.

OpenGL
OpenGL2765×1525 84.8 KB

Direct3D
Direct3D1920×1069 51.2 KB

4

Hi Sach -

I would start by updating the GPU drivers using the “clean install” option.
-wim

5

I’ll try that. Any idea why it’s working in R8 though? Thanks

6

Every version of Rhino leans on OpenGL more, so more to go wrong with drivers.

Also OpenGL is just about dead so V9 is switching to DirectX, that’s probably what you’re actually running, so that’s a whole new set of bugs.

7

@wim It’s the same after updating the both graphics drivers…

8

@JimCarruthers thanks.

I switched to OpenGL is because I thought the model was a bit zipper to spin around the viewport. I’ll just keep it set to Direct3D.

1 Like
9

It may be a bit zippier for now. The current focus for Direct3D is to make sure everything looks correct. Once that is done we will focus on areas where we can try to improve the speed.

10

Okay, thanks