This page covers the various environment variables for use in V-Ray Standalone.


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There are some environment variables that affect the operation of V-Ray. Some of these variables are universally used by V-Ray Standalone and application specific installations of V-Ray, while some of them are pertinent to V-Ray Standalone only. The variables that are valid for V-Ray Standalone only are marked with (standalone).



VRAY_AUTH_CLIENT_FILE_PATH – Points to the folder containing the vrlclient.xml file that contains the V-Ray license server settings (IP address and port number).

VRAY_CONNECT_TIMEOUT – The timeout duration (in milliseconds) when connecting to the license server.


Command Line

VRAY_CMD_PREFIX  (standalone) – Specifies command-line options for V-Ray standalone which are prepended to the actual command line.

VRAY_CMD_SUFFIX  (standalone) – Specifies command line options that are appended to the actual command line.


Render Assets

VRAY_ASSETS_PATH  – Specifies a list of paths where V-Ray will look for textures, GI cache files etc. Initially, V-Ray will attempt to look for an asset in the path specified in the scene. If this fails, V-Ray will go through the paths in the  VRAY_ASSETS_PATH  variable and try to find a file with the same name. On Windows, paths are separated with semicolon ';' and on Linux and Mac OS X - either a colon ':' or semicolon ';'

VRAY_TEXTURES_LOAD_16BIT_AS_8BIT  – When set to 1, V-Ray will load 16-bit PNG and TIFF texture files as 8-bit in memory.

VRAY_PLUGINS_x86 and VRAY_PLUGINS_x64 (standalone) – Specifies a list of paths for additional V-Ray plugins. Paths are separated with ';' on Windows and ';' or ':' on Linux/Mac OS X.

VRAY_TEXTURE_CACHE  – Specifies the size, in megabytes, of a separate texture cache to be used for tiled OpenEXR files. If this is not present, or the value is  0 , the same cache is shared between dynamic geometry and tiled textures. One of the advantages of a separate texture cache is that it is persistent across the frames when rendering an animation.


VFB Control

VRAY_VFB_SRGB (standalone) – When set to 1 , the sRGB button of the V-Ray VFB is automatically switched on. When set to 2, the sRGB button of the V-Ray VFB is switched off.

VRAY_VFB_LUT  (standalone) – When set to  1 , the LUT color correction is enabled by default. The LUT file is specified with the VRAY_VFB_LUT_FILE environment variable.

VRAY_VFB_LUT_FILE  – Specifies the path and name of the LUT file.

VRAY_VFB_PIXEL_ASPECT  (standalone) – When set to  1 , the pixel aspect correction for the VFB is automatically enabled.

VRAY_VFB_GLOBAL_PRESET_FILE  Points to the Globals preset file path.

VRAY_VFB_GLOBAL_PRESET_FILE_USE – When set to 1, the VFB uses the specified Globals preset file. 


Distributed Rendering

VRAY_DR_SUBNET  – Specifies the subnet mask for broadcast messages. This is currently used only when a render server is started so that it can join a DR render.


Ray Differentials

VRAY_USE_NORMAL_DIFFERENTIALS  – When set to  1 , V-Ray will use the surface curvature when calculating ray differentials for secondary rays for reflection, refraction, and GI. This is typically useful with tiled OpenEXR and TIFF textures, as it will produce a more accurate estimate for the required mip-map level (which otherwise might be overestimated resulting in a more detailed level being loaded than is really necessary).



VRAY_OPENCL_PLATFORMS_x64 – Specifies the CUDA or OpenCL devices to be used for V-Ray RT GPU rendering. This variable is automatically set when a device is selected using the V-Ray RT GPU settings in 3ds Max (or the equivalent external tool provided with the V-Ray installation ocldeviceselect.exe ). If the variable is not set, all available devices will be used. The syntax allows a case insensitive pattern matching of any value to a device name, vendor, type and its index. More than one values can be specified by separating them with a semi-column.

VRAY_OPENCL_PLATFORMS_x64=gpu // only GPU devices will be used
VRAY_OPENCL_PLATFORMS_x64=titan;amd // Titan GPUs and AMD GPUs will be used
VRAY_OPENCL_PLATFORMS_x64=intel cpu;gtx 980 // Intel CPU OpenCL devices and GTX 980 devices will be used
VRAY_OPENCL_PLATFORMS_x64=titan index0;titan index2 // the first and third GTX Titan graphics card installed on the machine will be used