I get an error message "Unable to checkout GUI license."

 There are several possible causes for this error:

  • There is no V-Ray Online License Server installed or running on the machine. You will need to install the V-Ray OLS or. if it is already installed, run it using the "Start V-Ray Online License Server" executable.
  •  A remote licensing server is used but its address is improperly set. You might need to edit the V-Ray OLS address using the "Change Your License Settings" executable. Please refer to the Changing your License Settings page for further details.
  • There are no available licenses on the account used by the V-Ray OLS. Open the V-Ray OLS web interface on http://localhost:30304 or http://[SERVER_IP]:30304 where [SERVER_IP] is the IP address of the machine where V-Ray OLS is installed and running. See whether the correct licenses exist on the currently logged account and whether they are available for use. For more information please see the Dongle usage page.
 I cannot start the V-Ray for SketchUp installer.

It is possible that the installation file is not downloaded properly, which might cause your installer application to crash when you attempt to run it. In this case, please re-download the installation file from our website.

 GPU Accelerated Interactive rendering with V-Ray for SketchUp takes a long time to start.

GPU Accelerated Interactive rendering with V-Ray might take a while to start up the first time you run it on a specific graphics card. Each subsequent start should be almost instantaneous, even after closing and re-opening SketchUp.

Installing a new version of V-Ray, however, or the same version of V-Ray on a new machine, or installing a new graphics card will again take a while to start up, but only the first time after making such changes.

If you experience other problems with Interactive rendering and GPU Acceleration, please contact Chaos Group Support

 I get an out-of memory error when using GPU Accelerated Interactive rendering with V-Ray.

Graphics cards used for GPU Accelerated Interactive rendering with V-Ray have their own available memory. You might have tried to load more scene information that your graphics card can handle. Try using lower texture size for your scene; V-Ray can automatically change the texture size when using GPU Acceleration. This is adjusted in the advanced view of the Raytrace rollout under GPU textures.

In Raytrace advanced > GPU Textures make sure you have the Resize parameter set to Resize textures and try using a lower Texture Size and/or lower Bit-Depth value.

If you experience other problems with Interactive rendering and GPU Acceleration, please contact Chaos Group Support.

 I can't start GPU Accelerated rendering.

Make sure you are using the latest available video drivers for your video graphics card. Look up the driver downloads on the website of your graphics card vendor.  GPU OpenCL render mode is currently not supported. GPU CUDA is available only for Fermi-, Kepler-, Maxwell- and Pascal- based NVIDIA cards.

If you experience other problems with Interactive rendering and GPU Acceleration, please contact Chaos Group Support.

 My system locks up and freezes while rendering.

This is most likely a hardware problem, since V-Ray cannot cause a system freeze by itself. The worst that may happen when rendering is crashing SketchUp. Check your memory components and other system hardware and make sure to check your CPU and system temperature in case of over-heating.

 I get error messages in the V-Ray Progress Window.

The exact text in the message may differ, depending on where the error occurred in V-Ray. There are different reasons for error messages to appear:

  • Unhandled exception – This message might be generated when there is insufficient RAM to render the scene. See the section on Excessive memory usage for more details. Another reason could be the increased clock speed of modern processors, characterized by random crashes during rendering, which can be difficult to distinguish from a software problem. Installing CPU temperature monitoring software and checking RAM for defects might help to determine whether the problem is in the hardware or the software.
  • Incompatibility with other plugins – If you suspect this is the reason for the error, please contact Chaos Group Support and the plugin vendor and explain the situation. Please note that the problem might be in the plugin and not in V-Ray.
  • A bug in V-Ray – If you believe you have found a bug, please try to isolate the issue (i.e. identifying if it occurs in a specific situation related to a certain object, material, atmospheric effect, etc.) and contact Chaos Group Support.
 Rendering uses an excessive amount of memory.

Like other applications, V-Ray needs a certain amount of RAM to render an image. Depending on the scene complexity and the render settings, V-Ray will use varying amounts of RAM. Sometimes, the available system RAM might be less than the amount needed for rendering, in which case you will likely get an unhandled exception. Check the memory usage from the Windows Task Manager.

If rendering your scene increases memory usage to the point where it cripples your machine, there are a few things that you can look at to improve performance:

  • Geometry – Scenes with a large number of objects and/or high triangle counts require more memory to render. There are a few ways to reduce this amount:
  • V-Ray Fur can increase memory usage. If you have a lot of fur in your scene, make sure you have enabled the level of detail option for the V-Ray Fur.
  • Try enabling the Conserve Memory option in the System rollout.
  • If all else fails, use V-Ray Proxy | VRayProxy objects.


  • Displacement mapping – Displacement usually requires a substantial amount of memory. You can lower the quality settings for displacement and make it view-dependent to reduce memory usage:
  • As a first step, make sure that displacement is indeed causing excessive memory usage. In the Switches rollout, under the Geometry section, disable Displacement and render your scene. If memory usage is substantially decreased, then this is the cause of the excessive memory use. Re-enable Displacement once again and adjust the displacement objects that you find in the Displacement rollout of your material settings:
  • Enable the View dependent option for displacement.
  • Lower the Max subdivs value.
  • Increase the Edge length value.


  • Bitmaps – These tend to take up large amounts of RAM, especially if the maps are large.You can potentially reduce the RAM usage by lowering the quality of the bitmap textures you are using.


  • Image buffer – Large output resolutions require a significant amount of RAM to store the final image, and additional Render elements increase that amount. There are several ways to reduce this amount: 
  • Render the image in several different passes, where each pass contains different render elements.
  • Render the image in several different passes, where each pass renders only a region of the image and then stitch the pieces together in a compositing application.


  • Image samplers (AA) – The image sampling algorithms of V-Ray require some amount of RAM to hold all the data for the sampled image. This amount can be large, depending on the sampler type - the progressive sampler usually requires more memory than the non-progressive (bucket) sampler. If you're using the bucket sampler, you can reduce the bucket size chosen bucket size.
  • The non-progressive (bucket) sampler can be set to use lower bucket size. Check the settings in the Raytrace rollout and look for the bucket size settings in the Optimizations rollout.
  • The progressive sampler usually requires more memory than the non-progressive (bucket) sampler. The memory usage can increase when you're rendering at high resolutions.


  • Global illumination – Irradiance maps and light maps all require additional memory to store. Each of these has different methods for controlling its memory usage:
  • For Irradiance map, the memory depends on the number of samples in the map; you can reduce this number by using a lower Min/Max rate, and looser threshold values (higher Color threshold, higher Normal threshold, lower Distance threshold).
  • For Light cache, increase the Sample size.


  • SketchUp scene – SketchUp itself stores a lot of information about the scene. V-Ray has no control over that memory usage, but there are some things you can do to reduce it. Try purging your scene of unnecessary geometry by navigating to Window > Model Info > Statistics > Purge Unused. This will eliminate any unused geometry, materials, styles, and layers from your scene.
 I get splotches in my render when using the irradiance map.

There may be several reasons for splotches when rendering with the irradiance map. Regular noisy splotches are usually the result of insufficient Hemispheric subdivisions for the irradiance map. Usually they appear in difficult lighting situations when the default setting is too low. Examples of difficult lighting conditions are small bright sources of indirect light and HDRI environments.

You can avoid these splotches in a few ways:

  • If you are using brute force GI for secondary GI bounces, try using another method such as Light Cache.
  • Increase the Hemispheric subdivisions for the Irradiance map.
 Does V-Ray for SketchUp support GPU rendering?

GPU rendering is supported in V-Ray for SketchUp, but it currently does not support all available V-Ray features. GPU OpenCL render mode is currently not supported. GPU CUDA is available only for Fermi-, Kepler-, Maxwell- and Pascal- based NVIDIA cards.  For more information, see the Supported Features page. 

 Which hardware works best with V-Ray?

Rendering is all about number-crunching. This means that a powerful processor is the best place to focus when choosing a machine. Chaos Group does not recommend any specific brand or endorse a particular model of computer, processor or other component.

To test your system resources and gauge how well your system can render V-Ray scenes using both the CPU and a CUDA-enabled GPU, you can use V-Ray Benchmark. Through a standalone executable, V-Ray Benchmark scores how fast your system can render sample scenes of common V-Ray uses without even having V-Ray installed.

You can search for specific hardware results, and see other test results, at benchmark.chaosgroup.com.

 How can I locate the records of my other Chaos Group purchases?

Contact Chaos Group Support with as much information as you have about the purchases and we will be glad to locate the records in our system.