In Rhino 8, up-to-date, having problem with a simple solid extrusion appearing transparent in render mode. Any ideas of why?
Could this be related to a sudden “out of GPU memory” issue when doing render preview? The model is only 55 MB.
Usually when an object is unexpectedly transparent, it means the render mesh is bad, and you are seeing the backside of the mesh - it is inside-out. That also usually means your object has a problem, often bad trims. What does the command What say about your object?
This transparency issue is also affecting the render preview operation. With the transparent solids (2) present, I get the out of GPU memory error msg. When they are removed, it renders fine.
I recall that the solid was created by forming a surface from two planar curves and then extruding them. They are part of a block.
polysurface
ID: 41bdff49-3a8b-41fc-b389-5aff9562b561 (782)
Object name: New CBM hatch open
Layer name: Create blocks on this layer::New CBM hatch::New CBM hatch open
Render Material:
source = from obj
index = 151
Attribute UserData:
UserData ID: CE28DE29-F4C5-4faa-A50A-C3A6849B6329
Plug-in: 17b3ecda-17ba-4e45-9e67-a2b8d9be520d
description: User text (0 entries)
saved in file: yes
copy count: 104
Geometry:
Valid polysurface.
closed solid polysurface with 11 surfaces.
Edge Tally:
1 seam edges
26 manifold edges
= 27 total edges
Edge Tolerances: all smaller than 0.000001
Vertex Tolerances: all 0.00
Render mesh: 11 meshes 966 vertices 780 polygons
Created with quality meshing parameters.
Analysis mesh: none present
Can you post the Rhino file here?
Test block.3dm (488.2 KB)
The transparent object is part of a block. I exported the block, exploded it to remove the other OK parts and added a red sphere. The transparency is best seen in the perspective view set to rendered.
Thank you for your interest.
Hmm, I’m not seeing any transparency here… Some reflections yes, but no transparency. No GPU problems either. I have an RTX 4070 Super with 12Gb VRAM.
Can you run SystemInfo in Rhino and post the results here?
Rhino 8 SR29 2026-3-4 (Rhino 8, 8.29.26063.11001, Git hash:master @ bbd126f84fcdaf7a974615b7c9f4f8667571c147)
License type: Commercial, build 2026-03-04
License details: Stand-Alone
Windows 11 (10.0.26200 SR0.0) or greater (Physical RAM: 32GB)
.NET 8.0.14
Computer platform: LAPTOP - Plugged in [50% battery remaining]
Non-hybrid graphics configuration.
Primary display and OpenGL: NVIDIA GeForce GTX 1650 Ti (NVidia) Memory: 4GB, Driver date: 3-4-2026 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 595.79
Integrated accelerated graphics device with 1 adapter port(s)
- Windows Main Display is laptop’s integrated screen or built-in port
Primary OpenGL: NVIDIA GeForce GTX 1650 Ti (NVidia) Memory: 4GB, Driver date: 3-4-2026 (M-D-Y). OpenGL Ver: 4.6.0 NVIDIA 595.79
Integrated accelerated graphics device with 1 adapter port(s)
- Windows Main Display is laptop’s integrated screen or built-in port
Secondary graphics devices.
Intel(R) UHD Graphics (Intel) Memory: 1GB, Driver date: 5-5-2020 (M-D-Y).
Integrated graphics device with 3 adapter port(s)
- Secondary monitor is laptop’s integrated screen or built-in port
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: 4x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: High
Vendor Name: NVIDIA Corporation
Render version: 4.6
Shading Language: 4.60 NVIDIA
Driver Date: 3-4-2026
Driver Version: 32.0.15.9579
Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24 bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 4 GB
Rhino plugins that do not ship with Rhino
Rhino plugins that ship with Rhino
C:\Program Files\Rhino 8\Plug-ins\Commands.rhp “Commands” 8.29.26063.11001
C:\Program Files\Rhino 8\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 8\Plug-ins\RhinoRenderCycles.rhp “Rhino Render” 8.29.26063.11001
C:\Program Files\Rhino 8\Plug-ins\rdk_etoui.rhp “RDK_EtoUI” 8.29.26063.11001
C:\Program Files\Rhino 8\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 8\Plug-ins\MeshCommands.rhp “MeshCommands” 8.29.26063.11001
C:\Program Files\Rhino 8\Plug-ins\RhinoCycles.rhp “RhinoCycles” 8.29.26063.11001
C:\Program Files\Rhino 8\Plug-ins\Toolbars\Toolbars.rhp “Toolbars” 8.29.26063.11001
C:\Program Files\Rhino 8\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 8\Plug-ins\Displacement.rhp “Displacement”
C:\Program Files\Rhino 8\Plug-ins\SectionTools.rhp “SectionTools”
That looks more or less OK, 4Gb is a bit at the lower limit for a graphics card but I think it should still be OK. I don’t know why you are getting a GPU out of memory error. The only thing I could see is to update the Intel driver from 2020 and see if that makes a difference, and perhaps do a clean re-installl of the NVidia driver.
I successfully render quite large, complex models 300 MB or more, so I don’t think it is a GPU issue.
I used block edit in place to duplicate the edges of the solid, join the inner openings separate curves, delete the original solid that was transparent, create a new surface from the two planar curves, and extrude the surface. The new replacement solid was transparent.
I then duplicated just the outside curve, extruded that curve so that the solid did not have a center opening, and it was not transparent. I then used the curve from the inner opening to extrude a solid that I used with boolean difference to create the opening in the extruded curve’s solid without an opening. This recreated the solid with the opening. It was not transparent.
This appears to be a fix for this but I worry about complex solids behaving in this manner.
I made the “fix” to the blocks affected. The entire model than renders fine in preview.
The issue appears to be creating the surface from the coplanar curves to then extrude to create the solid with the inside opening.
Thank you for your help. An interesting issue, certainly. Not sure it is a GPU issue.
Rhino tech support identified that the cause of the transparency was that the object’s properties had “receives shadows” checked. Don’ t know how that happened but unchecking appears to have resolved the issue.
Actually, the problem arises because ‘Casts shadows’ is unticked. The default for both these shadow options is ticked, so rather than untick receives, tick casts. Solves the issue and keeps you in line with the norm.
HTH
Jeremy
Thank you for that insight.