Rendering Latest WIP/Windows

Hi McNeel:

A couple of things I found rendering using the latest WIP for Windows which may already be known.

A) Using a custom environment for reflections, should reflections be handled differently between “Rendered” display and “Raytraced” display?

B) Should I be seeing these times for CPU vs. GPU when using Rhino Render to render scenes. It seems that in a previous build the times were flipped, GPU showed a substantially faster render time than CPU.

C) I’m still getting, when I have selected GPU in Cycles settings and I select Raytrace for a display rendering, a rendering hangup and it will not complete renderings. When I go back into cycles settings and change back to CPU, it renders the display correctly.

System Info:

Rhino 7 SR0 2020-3-11 (Public Build, 7.0.20071.05245, Git hash:master @ 9de0cf84238aa0c334831df29d24be49fa879000)
License type: Commercial, build 2020-03-11
License details: Cloud Zoo. In use by: -jvm ()
Expires on: 2020-04-25

Windows 10.0 SR0.0 or greater (Physical RAM: 64Gb)
Machine name: MSI

Non-hybrid graphics.
Primary display and OpenGL: NVIDIA GeForce GTX 1070 (NVidia) Memory: 8GB, Driver date: 1-29-2020 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 442.19

Secondary graphics devices.
NVIDIA GeForce GTX 1070 (NVidia) Memory: 8GB, Driver date: 1-29-2020 (M-D-Y).

OpenGL Settings
Safe mode: Off
Use accelerated hardware modes: On
Redraw scene when viewports are exposed: On

Anti-alias mode: 4x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: Height

Vendor Name: NVIDIA Corporation
Render version: 4.6
Shading Language: 4.60 NVIDIA
Driver Date: 1-29-2020
Driver Version:
Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24 bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 8 GB

Rhino plugins
C:\Program Files\Rhino 7 WIP\Plug-ins\Commands.rhp “Commands” 7.0.20071.5245
C:\Program Files\Rhino 7 WIP\Plug-ins\WebBrowser.rhp “WebBrowser”
C:\Program Files\Rhino 7 WIP\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 7 WIP\Plug-ins\RhinoScript.rhp “RhinoScript”
C:\Program Files\Rhino 7 WIP\Plug-ins\IdleProcessor.rhp “IdleProcessor”
C:\Program Files\Rhino 7 WIP\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 7.0.20071.5245
C:\Program Files\Rhino 7 WIP\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 7.0.20071.5245
C:\Program Files\Rhino 7 WIP\Plug-ins\rdk_ui.rhp “Renderer Development Kit UI”
C:\Program Files\Rhino 7 WIP\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 7 WIP\Plug-ins\Alerter.rhp “Alerter”
C:\Program Files\Rhino 7 WIP\Plug-ins\RhinoCycles.rhp “RhinoCycles” 7.0.20071.5245
C:\Program Files\Rhino 7 WIP\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 7.0.20071.5245
C:\Program Files\Rhino 7 WIP\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 7 WIP\Plug-ins\Displacement.rhp “Displacement”

Hi Jim -

should reflections be handled differently between “Rendered” display and “Raytraced” display?

Yes. rendered display is a cheap but fast openGL display - it does not calculate reflections like a raytrcer.
I’d expect the GPU to be faster for the same resolution, yes. But there may be all kinds of whys and wherefores … @nathanletwory will know better…

I gather from the images in B that your symptom in C is intermittent, correct?
Does the Render command work?


As @pascal already mentioned reflections are handled differently. In Rendered mode you get only environment reflection. In Raytraced you get proper reflection, including inter-object

If you could do the timings again such that once you’ve selected your render device and started a Raytraced viewport you click on the name Raytraced (Cycles). You should see in the HUD on what device the rendering is happening.

Remember to always restart the Raytraced viewport after changing render device (toggle to other display mode, then back to Raytraced).

If you get the unexpected GPU being slower than CPU then maybe you could share the file with me at

Hopefully next week we’ll have some improvements on that. Last week some rather big behind-the-scene change was made, it may be causing some trouble here. Other than that, same request as in answer to B). A file to test with would be useful.

Hi Cal-

Correct, C is intermittent. I’ll send a file to Nathan. The render command does work correctly, I think.



Hi Nathan,

I sent you a file. I also just ran the file I sent you which was a saved version of a much larger scene and it seems to render correctly – CPU time (is slower) vs GPU time (faster) which is what I had expected to see. I’m not sure why I was seeing those reversed.