Buy VRay

Buy VRay - $899   Buy VRay (Educational Version) $240 Buy VRay - Bundle $999 Buy VRay - Super Bundle $1135

If you experience any problems not discussed below while using VRay, please write to vray@chaosgroup.com

Search Keywords: problems, troubleshooting, bug

My system locks up and freezes while rendering

This is most likely a hardware problem. VRay cannot cause system freeze by itself. The worst that VRay can do is crash 3dsmax. Check your memory chips and/or your CPU temperature.

I get an "unhandled exception" message window while rendering:

The exact text in the message box may differ, depending on where in VRay the error occurred. There are different reasons for this message to appear:

• Insufficient RAM - one of the most common reasons for the unhandled exception. See the section on Excessive memory usage below for more details.
• CPU overheating or RAM defects - this is another reason for unhandled exceptions that has become quite common recently with the increased clock speed of moden processors. It is characterized by random crashes during rendering and may be quite difficult to distinguish from a software problem. Installing a CPU temperature monitoring software and checking the RAM for defects may help to determine whether the problem is in the hardware or the software.
• Crashes with motion blur enabled - A common problem is when there are motion-blurred objects depending on one another; in that case, hiding the original object and using a copy of it for rendering helps.
• Using the native 3dsmax Skylight light type - either on its own, or as a part of the Daylight system. If this is the case, use VRay's own environment dialog to create the skylight effect.
• Incompatibility with other plugins - if you suspect this is the reason for the error, please write to vray@chaosgroup.com and to the plugin vendor and explain the situation. Please note that the problem might be in the plugin, and not in VRay. Some plugins were specifically coded for the default scanline renderer and may behave unpredictably with VRay.
• A bug in VRay - if you believe that this is the problem, try to isolate it (if it occurs in a specific situation related to a certain object, material, atmospheric effect etc.) and email the file c:\vraylog.txt as well as the 3dsmax scene to vray@chaosgroup.com

Excessive memory usage while rendering

Like every other program, VRay needs a certain amount of RAM to render the image. Depending on the scene complexity and the render settings, VRay will use varying amounts of RAM. Sometimes, the available system RAM may be less than the amount needed for rendering. In this case, you will most likely get an unhandled exception. You can check the memory usage from the Windows Task Manager.

On 32-bit machines, the Windows® operating system allows by default up to 1.5 GB for any single process (application). That means that even though you may have more physical RAM (for example 2GB), the operating system will not allow an application to use all of that memory.

However, on the Windows® XP operating system, you can change this by using the famous /3GB switch in your boot.ini file. This will enable the OS to allocate up to 3 GB of RAM for any given application. Using that switch may allow you to render your scene without using any of the methods below for reducing memory usage.

On 64-bit platforms, the 64-bit version of the Windows® operating system allows the usage of all available physical memory without limitations.

If you cannot use any of these methods to allow more RAM for rendering, the only choice is to reduce the amount that is needed by changing your scene and your VRay settings.The scene elements that take up most of the RAM while rendering can be divided into the following groups:

• Geometry - scenes with lots of objects and/or triangle counts require more memory to render. There are several ways to reduce this amount:
  • Adjust the raycaster settings in the System rollout (reduce Max. levels, increase Min. leaf size, increase Face/level coefficient, switch from Static to Dynamic Default Geometry).
  • If all else fails, use VRayProxy objects.
• Mapping UVW channels - in 3dsmax, every mapping channel takes up the same or larger amount of RAM as the geometry itself. Unused mapping channels can increase RAM usage dramatically, while not affecting the scene in any way. In recent 3dsmax versions, texture channels are generated by default for all objects when they are created. VRay has no control over RAM usage for texture coordinates - you will have to make sure that only the channels you need are actually present in the scene. Using VRayProxy objects is also a solution since in that case texture coordinates are also cached to disk along with the actual geometry.

• Displacement mapping - objects displaced with the 2d displacement mapping method may require a lot of RAM to render, especially with large displacement maps. If this is the case, use the 3d displacement mapping method. Also, if you have several distinct displacement modifiers with the same displacement map, it is better to replace them with one modifier, applied to all the necessary objects. This is because each modifier will take RAM for the displacement map, separately from other modifiers, even if they have the same map.
• Bitmaps - these tend to take up large amounts of RAM, especially if the maps are large. Since textures are managed by 3dsmax, VRay has no direct control over their memory usage. However, you can use the Bitmap pager settings of 3dsmax to reduce the RAM taken up by bitmaps. For more information, consult your 3dsmax documentation.
• Bitmap filtering - Summed area filtering uses much more memory than Pyramidal filtering.
• Shadow maps - these may also take up significant amounts of RAM. Again, these are managed by 3dsmax and VRay has no direct control over their memory usage. To reduce memory usage, you can switch to raytraced VRayShadows instead.
• Image buffer - large output resolutions require a significant amount of RAM to store the final image. Additional G-Buffer channels increase that amount. There are several ways to reduce this amount:
  • Use the 3dsmax Bitmap pager, if you are rendering to the 3dsmax default VFB.
  • If you use VRay's own VFB, use the Render to VRay raw image file option and then use the VRay raw image file viewer to convert the resulting file to a different format.
  • Render the image in several different passes and stitch the pieces in a compositing program.
• Image samplers (AA) - the image sampling algorithms of VRay require some amount of RAM to hold all the data for the sampled image. This amount can be quite large, depending on the chosen bucket size and sampling rate. To reduce that amount:
  • Reduce the bucket size.
  • Switch to a different image sampler - for example, the Adaptive QMC sampler uses less RAM than the Adaptive subdivision sampler.
• Global illumination caches - irradiance maps, photon maps and light maps all require additional memory to store them. Each of these has different methods for controlling its memory usage:
  • For the irradiance map - the memory depends on the number of samples in the map; you can reduce this number by using lower Min/Max rate, and more loose threshold values (higher Color threshold, higher Normal threshold, lower Distance threshold).
  • For the photon map - the memory depends on the number of photons stored. You can reduce this number by reducing the Diffuse subdivs for the lights, or by increasing the Max. density.
  • For the light map - increase the Sample size.
• 3dsmax scene - 3dsmax itself stores a lot of information about the scene. VRay has no control over that memory, but here are some things you can do to reduce it:
  • Collapse modifiers to editable meshes
  • Cache animations with a PointCache modifier

I get splotches in my rendering when using the irradiance map

There may be several reasons for splotches when rendering with the irradiance map:

• Regular noisy splotches - these are usually a 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, hdri environments etc. You can avoid these splotches in several ways:
  • If you are using Quasi-Monte Carlo GI for secondary GI bounces, try using another method - the light map or the photon map.
  • Increase the Hemispheric subdivisions for the irradiance map. Note that the effect of the increased subdivisions depends also on the settings of the QMC sampler.
  • Decrease the Noise threshold of the QMC sampler.

• Isolated bright splotches - there may be different causes for these:
  • GI caustics - if you have reflective or refractive surfaces in your scene, especially if they are glossy, VRay may try to compute the GI caustics for these surfaces. Since caustics usually require a lot of sampling to get right, there may be splotches.
  • Incorrect or missing UVW coordinates - if some objects in your scene lack UVW coordinates, or the UVW coordinates fall outside the texture map, this can produce splotches or weird colors in the irradiance map. The solution would be to apply correct UVW coordinates to those objects.

Follow our newsfeed for all latest product updates and discounts

Your cart Cart is empty View cart Checkout

Authentication Username Password Log in Register Recover password If you have disabled Javascript in your browser click here

VRay News Populate your scenes quickly and professionally with Evermotion's 3D Archmodels! Add top quality props to your scene within minutes. Archmodels provides professional high quality 3D models for your visuals. Click for more details

Popular Products Archexteriors Vol. 10 Archinteriors Vol. 15 Professional VRay Shaders VRay Advanced - Bundle Learn VRay Exteriors Gnomon DVD Learn VRay Interiors Gnomon DVD