The rhino8 ray trace view runs very slowly.
I am having trouble changing materials easily because it is so slow, including the UI.
Running it with a small number of samples does not solve the problem.
The rendering itself completes in an instant.
In blender, which is the same cycles, I can see the rendered image in real time very comfortably.
Is this a specification of Rhino8? Or am I missing some critical setting?
Hi @rhinoman_666
Welcome to the forum 
The first thing to do is to run the SystemInfo command in Rhino and copy/paste the resulting text in its entirety here on discourse for people to look at - thatâll probably give an idea of what might be going on
HTH, Jakob
Thanks for the reply.
It looks like the following. I have hidden the username.
Rhino 8 SR17 2025-3-7 (Rhino 8, 8.17.25066.07001, Git hash:master @ b14fcd901289f8715631debb308bc919a4988e07)
License type: Commercialăăă«ă 2025-03-07
License details: Cloud Zoo
Windows 11 (10.0.26100 SR0.0) or greater (Physical RAM: 64GB)
.NET 7.0.0
Computer platform: LAPTOP - Plugged in [89% battery remaining]
Hybrid graphics configuration.
Primary display: Intel(R) Iris(R) Xe Graphics (Intel) Memory: 2GB, Driver date: 2-4-2025 (M-D-Y).
> Integrated graphics device with 4 adapter port(s)
- Secondary monitor is laptopâs integrated screen or built-in port
- Windows Main Display attached to adapter port #1
Primary OpenGL: NVIDIA RTX 4000 Ada Generation Laptop GPU (NVidia) Memory: 12GB, Driver date: 2-25-2025 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 572.60
> Integrated accelerated graphics device with 4 adapter port(s)
- Video pass-through to 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 GPUâs maximum)
Anti-alias mode: 4x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: High
Vendor Name: NVIDIA Corporation
Render version: 4.6
Shading Language: 4.60 NVIDIA
Driver Date: 2-25-2025
Driver Version: 32.0.15.7260
Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24 bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 12282 MB
Rhino plugins that do not ship with Rhino
C:\Users\myname\AppData\Roaming\McNeel\Rhinoceros\packages\8.0\FlatCap\0.0.4-alpha\FlatCap.Rhino.rhp âFlatCap.Rhinoâ 1.0.0.0
Rhino plugins that ship with Rhino
C:\Program Files\Rhino 8\Plug-ins\Commands.rhp âCommandsâ 8.17.25066.7001
C:\Program Files\Rhino 8\Plug-ins\rdk.rhp âRenderer Development Kitâ
C:\Program Files\Rhino 8\Plug-ins\RhinoRenderCycles.rhp âRhinoăŹăłăăŒâ 8.17.25066.7001
C:\Program Files\Rhino 8\Plug-ins\rdk_etoui.rhp âRDK_EtoUIâ 8.17.25066.7001
C:\Program Files\Rhino 8\Plug-ins\NamedSnapshots.rhp âSnapshotsâ
C:\Program Files\Rhino 8\Plug-ins\MeshCommands.rhp âMeshCommandsâ 8.17.25066.7001
C:\Program Files\Rhino 8\Plug-ins\RhinoCycles.rhp âRhinoCyclesâ 8.17.25066.7001
C:\Program Files\Rhino 8\Plug-ins\Grasshopper\GrasshopperPlugin.rhp âGrasshopperâ 8.17.25066.7001
C:\Program Files\Rhino 8\Plug-ins\Toolbars\Toolbars.rhp âToolbarsâ 8.17.25066.7001
C:\Program Files\Rhino 8\Plug-ins\3dxrhino.rhp â3Dconnexion 3D Mouseâ
C:\Program Files\Rhino 8\Plug-ins\Displacement.rhp âDisplacementâ
C:\Program Files\Rhino 8\Plug-ins\Calc.rhp âé»ćâ
C:\Program Files\Rhino 8\Plug-ins\SectionTools.rhp âSectionToolsâ
Hi @rhinoman_666
Hmmm, so nothing looks out of the ordinary and drivers are up-to-date 
What do you mean by
And then adding
Does that mean that the Raytraced viewport is slow, but if you use the Render command, to render in a separate window, itâll complete faster?
Also, is even a simple scene (eg. a box with a simple plastic material) slow, or is it only when complexity is added?
Iâm sure @nathanletwory will have additional questions
-Jakob
Sorry, my information was wrong.
There is not much difference in the increase in the number of samples when using the raytrace viewport and the render command.
However, I am having trouble with the slowness when re-rendering when changing angles in the ray trace viewport. Also, even without changing the camera angle, there is slowness in object selection and the operation of each UI.
The situation is not much different with simple objects.
And the number of objects I am dealing with originally itself is also small.
Which version of the Material panel are you using? If you have it as full preview mode, then try to set it to âtree viewâ.
Thank you for your suggestion! Unfortunately, the situation did not change.
Alright, next step is to see if you can make a minimum working example, such as a box and a plane to demonstrate the issue, then post the file here.
Maybe it is because of specific textures, or a block that youn have? But first is to see the failure in something transferrable. Screen recordings can also be useful.
I am not sure if this is an appropriate video, but here is the screen recording and the 3dm used.
test_box.3dm (136.0 KB)
have you turned on âOPTIXâ in your render settings?
It was actually off during screen recording. However, I just tried turning it on and nothing changed.
well, then something is wrong, your GPU (A4000 Ada, Laptop) should perform much better.
According to the task manager, the CPU usage was at 100% during the ray tracing viewport. I hope this is a hint to a solution.
and your throttle is set to zero?
High CPU usage? That is normal - even when you let the GPU do the rendering. I just checked, my CPU is also fully utilized when rendering with the GPU/OPTIX. In the taskmanager you can also check if your GPU is utilized. Is it?
It was 100.
I tried setting it to 0, but nothing seems to have changed.
Maybe it is better if cycles was a standalone software
Rhino needs itâs resources then cycles needs its resources
Just a hungry bunch
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I really donât know why this âthrottleâ setting even exists and even worse why its default value is turned on/100%. Adding to this nonsens is the lack of any information next to the setting that would explain to the user what this does. I bet the majority of users have it turned on and will never know that their rendering could be many times faster.
Doesnât seem to fix your problem though.
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Rhino or its viewport donât use OPTIX, so other than maybe VRAM and bandwidth there isnât much shared resources. That isnât an issue. The benefit of having the renderer integrated is huge for most workflows. You can quickly change the scene, hit render, change again, render and so on. With a standalone renderer you would typically need to export first, then you render.
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I donât know about rhinoceros in other environments as all the computers in my company are similar, but is there something wrong with my situation?
If this is normal operation of rhinoceros, I would consider an external renderer.
