---
title: "Environment Variables"
canonical: "https://documentation.chaos.com/space/VMAYA/111739735/Environment%20Variables"
format: markdown
---
This page covers the various environment variables for use in V-Ray for Maya.


## <span style="color: #000000">**Overview**</span>

---

<span style="color: #000000">There are some </span><span style="color: #000000">[environment variables](https://docs-chaos.atlassian.net/wiki/spaces/VNS/pages/115605616)</span><span style="color: #000000"> that affect the operation of V-Ray. Some of these variables are in effect in both V-Ray Standalone and V-Ray for Maya, 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). </span>

<span style="color: #000000">When installing V-Ray from a .zip file, please refer to </span><span style="color: #000000">[Environment setup](https://docs-chaos.atlassian.net/wiki/spaces/VMAYA/pages/111740384/Installation+from+zip#Environmentsetup)</span><span style="color: #000000"> for the appropriate environment variables.</span>

> ℹ️ Starting with V-Ray Next, the **_x64** suffix for environment variables is no longer used. However, using the _x64 suffix will still work as a fall-back, but it will print a warning.


## <span style="color: #000000">**Licensing**</span>

---

<span style="color: #333333">**VRAY_AUTH_CLIENT_FILE_PATH**</span><span style="color: #333333"> – Points to the folder containing the vrlclient.xml file that contains the V-Ray license server settings (IP address and port number).</span>

<span style="color: #333333">**VRAY_CONNECT_TIMEOUT**</span><span style="color: #333333"> – The timeout (in milliseconds) when connecting to the license server.</span>


## > Macro (anchor)

<span style="color: #000000">**Textures and Render Assets**</span>

---

<span style="color: #333333">**VRAY_ASSETS_PATH **</span><span style="color: #333333">– 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 a semicolon (;). On Linux and macOS, paths are separated by either a colon (:) or semicolon (;).</span>

> ✅ **Variable replacement** is also available in path parameters. This feature is applicable to textures and other render assets, as well as output filenames. For more information, see the [Environment Variables](https://docs-chaos.atlassian.net/wiki/spaces/VMAYA/pages/111743711/File+Names+for+Bitmap+Textures#EnvironmentVariables) section on the [File Names for Bitmap Textures](https://docs-chaos.atlassian.net/wiki/spaces/VMAYA/pages/111743711) page.

<span style="color: #333333">**VRAY_TEXTURES_LOAD_16BIT_AS_8BIT**</span><span style="color: #333333"> – When set to </span><span style="color: #000000">*1*</span><span style="color: #333333">, V-Ray will load 16-bit PNG and TIFF texture files as 8-bit in memory.</span>

<span style="color: #333333">**VRAY_TEXTURES_USE_SYNCOLOR**</span><span style="color: #333333"> – When set to 0, V-Ray will ignore the SynColor color space of the textures and work only with the standard V-Ray gamma attributes. </span>

<span style="color: #333333">**VRAY_PLUGINS (standalone)**</span><span style="color: #333333"> – Specifies a list of paths for additional V-Ray plugins. On Windows, paths are separated with a semicolon (;). On Linux and macOS, paths are separated by either a colon (:) or semicolon (;).</span>

<span style="color: #333333">**VRAY_TEXTURE_CACHE**</span><span style="color: #333333"> – Specifies the size, in megabytes (MB), of a separate texture cache to be used for tiled OpenEXR files. If this is not present, or the value is </span><span style="color: #333333">*0*</span><span style="color: #333333">, 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. This variable has a similar function to the</span><span style="color: #000000"> </span><span style="color: #000000">[Tiled texture cache size](https://docs-chaos.atlassian.net/wiki/spaces/VMAYA/pages/111739157)</span><span style="color: #000000"> </span><span style="color: #333333">System parameter and is only applied if it has a higher value than it.</span>

<span style="color: #333333">**VRAY_TERMINATE_ON_FRAME_END **</span><span style="color: #333333">– Causes V-Ray to directly exit after a frame is complete in order to avoid slowdowns when freeing memory.</span>

<span style="color: #333333">**VRAY_TERMINATE_ON_SEQUENCE_END**</span><span style="color: #333333"> – Causes V-Ray to directly exit after the sequence is complete in order to avoid slowdowns when freeing memory.</span>

> ⚠️ Use the **VRAY_TERMINATE_ON_FRAME_END **and** VRAY_TERMINATE_ON_SEQUENCE_END** environment variables only on render servers where each frame/sequence is rendered by a separate process (either Maya or V-Ray Standalone). Do not use this in interactive Maya sessions as it will cause Maya to exit immediately after a render (even a swatch render).

<span style="color: #000000">**VRAY_MAYA_KEEP_BITMAPS**</span><span style="color: #333333"> – Enables the bitmaps caching between renders (same as the </span><span style="color: #333333">**Cache bitmaps between renders**</span><span style="color: #333333"> option in the</span><span style="color: #000000"> </span><span style="color: #000000">[Rendering Overrides](https://docs-chaos.atlassian.net/wiki/spaces/VMAYA/pages/111739148)</span><span style="color: #000000"> </span><span style="color: #333333">rollout of the Render Settings dialog).</span>

<span style="color: #333333">**VRAY_FOR_MAYA_SHADERS**</span><span style="color: #333333"> – Specifies additional locations for shader description files, using the V-Ray for Maya SDK to extend V-Ray for Maya with custom shaders. This allows V-Ray to create custom Maya shading nodes for a V-Ray Standalone plugin and to specify how the shading node is translated to the V-Ray standalone plugin.</span>

<span style="color: #333333">**VRAY_MAX_OPEN_FILES**</span><span style="color: #333333"> – Sets a limit on the number of files that can be opened simultaneously. This allows users to set a limit that is lower than their OS default. V-Ray creates a pool of file handles using this specified value, and when the limit is reached, the remaining files are added to a queue.  When a loaded file is no longer used, it is freed from memory and a queued file is loaded in its place.</span>

<span style="color: #000000">**VRAY_PATH_REMAP_FILEPATH**</span><span style="color: #000000"> (standalone) – Specifies a path to an XML file with path remapping data. This environment variable is an alternative to the </span><span style="color: #000000">**-remapPathFile **</span><span style="color: #000000">flag. Example file:</span>

```
<RemapPaths>
    <RemapItem>
        <From>Z:/export</From>
        <To>/mnt/export</To>
    </RemapItem>
</RemapPaths>
```

<span style="color: #000000">**VRAY_PATH_REMAPPING_CASE_SENSITIVE**</span><span style="color: #000000"> – Determines whether the file paths' capitalization is affected when remapping file paths </span><span style="color: #172b4d">(using the -</span><span style="color: #000000">remapPathFile</span><span style="color: #172b4d"> flag or </span><span style="color: #000000">VRAY_PATH_REMAP_FILEPATH</span><span style="color: #172b4d"> environment variable)</span><span style="color: #000000">. When set to 1, capitalization in names is not affected. When set to 0, or not set at all, capital letters in file path names are converted to lowercase.</span>


## <span style="color: #000000">**Asset Caching **</span>

---

<span style="color: #333333">Asset caching can be used for copying network assets locally on render node machines. Additionally, the same setup can be used together with Distributed Rendering to specify how and where transferred assets are cached.</span>

<span style="color: #333333">**VRAY_ASSETS_CACHE_PATH **</span><span style="color: #333333">– When set on a machine that is used as a render server during distributed rendering, this variable specifies the path where V-Ray will store the transferred assets.</span>

<span style="color: #333333">**VRAY_LOCAL_CACHE_LIMIT_TYPE**</span><span style="color: #333333"> - Specifies a local cache for rendering assets. The assets are copied locally for use by V-Ray, so that the original assets can remain unlocked for editing in other applications. This variable specifies the limit type of the cache, while </span><span style="color: #333333">**VRAY_LOCAL_CACHE_LIMIT_VALUE**</span><span style="color: #333333"> specifies the limit size of the cache. The limit is not applied during rendering, files are cleaned up after the render finishes. By default, the local cache is written to a vray_assets_cache folder placed (and automatically created) in the user's temp directory. The </span><span style="color: #333333">**VRAY_ASSETS_CACHE_PATH**</span><span style="color: #333333"> variable can be used to specify a different location for the local cache.</span>

<span style="color: #333333">**-1**</span><span style="color: #333333"> - disabled (default)</span>  
<span style="color: #333333">**0**</span><span style="color: #333333"> - no limit</span>  
<span style="color: #333333">**1**</span><span style="color: #333333"> - limit by age in hours. Files older than </span><span style="color: #333333">*N*</span><span style="color: #333333"> hours are deleted.</span>  
<span style="color: #333333">**2**</span><span style="color: #333333"> - limit by maximum size in gigabytes.</span>

<span style="color: #333333">**VRAY_LOCAL_CACHE_LIMIT_VALUE**</span><span style="color: #333333"> - A limit to the local asset cache. The meaning of the value depends on VRAY_LOCAL_CACHE_LIMIT_TYPE. Setting VRAY_LOCAL_CACHE_LIMIT_VALUE  to 0 will effectively delete all cached files after every render.</span>

> ℹ️ When local caching fails, the asset will still be loaded from its original network path.

<span style="color: #000000"> </span>

## <span style="color: #000000">**Distributed Rendering**</span>

---

<span style="color: #333333">**VRAY_DR_BROADCASTPORT**</span><span style="color: #333333"> – Specifies the port number used for broadcasting messages for joining a rendering. If not specified, port </span><span style="color: #333333">**20203**</span><span style="color: #333333"> is used. Make sure this port is opened so render servers can join the rendering.</span>

<span style="color: #333333">**VRAY_DR_SUBNET**</span><span style="color: #333333"> – 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.</span>

<span style="color: #333333">**VRAY_FOR_MAYA_DRPORT**</span><span style="color: #333333"> – Sets the default port to use when adding new distributed rendering servers in the Maya UI (from the</span><span style="color: #000000"> </span><span style="color: #000000">[DR Settings](https://docs-chaos.atlassian.net/wiki/spaces/VMAYA/pages/111743344/Distributed+Rendering+Settings#drSettings)</span><span style="color: #000000"> </span><span style="color: #333333">window). If you don't explicitly specify a port, the value set here will be used. If not set here, the default of </span><span style="color: #333333">*20207*</span><span style="color: #333333"> will be used.</span>

<span style="color: #333333">**VRAY_ASSETS_VERIFICATION_METHOD**</span><span style="color: #333333"> – When set on a machine that is used as a render server during distributed rendering, this variable specifies the asset verification method:</span>

<span style="color: #333333"> 0 - by modification date (default)</span>  
<span style="color: #333333">1 - by size</span>  
<span style="color: #333333">2 - by MD5 checksum</span>

<span style="color: #333333">**VRAY_NUM_THREADS**</span><span style="color: #333333"> – Manually sets the number of computation threads. By default (when "Max Render Threads" is </span><span style="color: #333333">*0*</span><span style="color: #333333">), V-Ray creates one computational thread per CPU core.</span>

<span style="color: #333333">**VRAY_KEEP_TEMP_VRSCENE**</span><span style="color: #333333"> – When set to a value of </span><span style="color: #333333">*1,*</span><span style="color: #333333"> the .</span><span style="color: #333333">*vrscene*</span><span style="color: #333333"> files from DR or local machines will not be deleted after rendering.</span>

<span style="color: #333333">**VRAY_VRSCENE_LOCATION **</span><span style="color: #333333">– When set on a machine that is used as a render server during distributed rendering, this variable specifies the path to store the temporary .</span><span style="color: #333333">*vrscene*</span><span style="color: #333333"> file. When this variable is not set, the default user temp directory is used.</span>

<span style="color: #333333">**VRAY_FOR_MAYA_DRLISTS_PATH**</span><span style="color: #333333"> – Specifies the path to an alternate DR XML configuration file. </span><span style="color: #333333">*For more information, see the *</span><span style="color: #000000">*[Distributed Rendering Settings](https://docs-chaos.atlassian.net/wiki/spaces/VMAYA/pages/111743344)*</span><span style="color: #000000">* page.*</span>


## <span style="color: #000000">**V-Ray GPU**</span>

---

<span style="color: #333333">**VRAY_GPU_PLATFORMS **</span><span style="color: #333333">– Specifies the CUDA devices to be used for V-Ray GPU rendering. This variable is automatically set when a device is selected using the</span> [V-Ray Render Settings](https://docs-chaos.atlassian.net/wiki/spaces/VMAYA/pages/111739167)<span style="color: #333333"> (or the equivalent external tool provided with the V-Ray installation </span><span style="color: #333333">*vray_gpu_device_select.exe*</span><span style="color: #333333"> ). 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 semicolon.</span>

<details>
<summary>VRAY_GPU_PLATFORMS Examples...</summary>

```csharp
VRAY_GPU_PLATFORMS=gpu // only GPU devices will be used
VRAY_GPU_PLATFORMS=titan;// Titan GPUs will be used
VRAY_GPU_PLATFORMS=intel cpu;gtx 980 // Intel CPU devices and GTX 980 devices will be used
VRAY_GPU_PLATFORMS=titan index0;titan index2 // the first and third GTX Titan graphics card installed on the machine will be used
```
</details>

<span style="color: #333333">**VRAY_MAC_GPU**</span><span style="color: #333333"> – Though GPU rendering with CUDA on macOS devices is no longer supported, the advanced users can bring back the old behavior by using this environment variable. Enabling this environment variable is at your own risk!</span>

<span style="color: #333333">**VRAY_OPTIX_DENOISER_PLATFORMS**</span><span style="color: #333333"> – Specifies the GPU devices used for denoising with the NVIDIA AI denoiser. This variable works similar to the </span><span style="color: #333333">**VRAY_GPU_PLATFORMS **</span><span style="color: #333333">one. From all devices that match the query, only the device with the highest compute capability is used for denoising.</span>

<span style="color: #333333">**VRAY_GPU_NVLINK_DISABLE**</span><span style="color: #333333"> – If set to 1, NVLink manager is disabled and it doesn't share VRAM between GPUs.</span>


## **AI Functionality**

---

> ✅ Chaos AI tools source data responsibly and encourage human authorship. *See our **[Responsible AI page](https://www.chaos.com/responsible-ai?srsltid=AfmBOopl3h57iDHmrA5zpdiN6zWnSWWuArFxv7kNeDUB8LlXj-mq5B7r)** for more information. *

**CHAOS_DISABLE_GEN_AI** – Specify whether the in-app AI functionalities are enabled in V-Ray. If the variable is set as a System Environment Variable, its value cannot be overridden with a process or user variable.

**0 **- enabled  
**1** - disabled


## <span style="color: #000000">**VFB Control**</span>

---

<span style="color: #333333">**VRAY_VFB_SRGB (standalone)**</span><span style="color: #333333"> – When set to </span><span style="color: #333333">*1*</span><span style="color: #333333">, indicates that the sRGB button of the V-Ray VFB is switched on by default. When set to </span><span style="color: #333333">*2*</span><span style="color: #333333">, the sRGB button of the V-Ray VFB should be switched off by default.</span>

<span style="color: #333333">**OCIO**</span><span style="color: #333333"> - Specifies the default OCIO color configuration if OCIO display color correction is enabled.</span>

<span style="color: #333333">**VRAY_VFB_OCIO**</span><span style="color: #333333"> – When set to </span><span style="color: #333333">*1*</span><span style="color: #333333">, the OCIO button of the V-Ray VFB is switched on by default. When set to </span><span style="color: #333333">*2*</span><span style="color: #333333">, the OCIO button of the V-Ray VFB is switched off by default.</span>

<span style="color: #333333">**VRAY_VFB_OCIO_INPUT_COLORSPACE**</span><span style="color: #333333"> - Specifies default overriding input OCIO color space. A default OCIO configuration can be specified by the OCIO environment variable.</span>

**VRAY_VFB_OCIO_VIEW_TRANSFORM** - Specifies default overriding OCIO view transform. A default OCIO configuration can be specified by the OCIO environment variable.

<span style="color: #333333">**VRAY_VFB_PIXEL_ASPECT (standalone)**</span><span style="color: #333333"> – When set to </span><span style="color: #333333">*1*</span><span style="color: #333333">, indicates that the VFB should have the pixel aspect correction enabled by default.</span>

<span style="color: #333333">**VRAY_WRITE_COLOR_CORRECTIONS **</span><span style="color: #333333">– When present and set to </span><span style="color: #333333">*0*</span><span style="color: #333333">, specifies that by default any color corrections to the final images written to the disk should be disabled.</span>

<span style="color: #333333">**VRAY_VFB_ICC**</span><span style="color: #333333"> - Enable (1) or Disable (2) the ICC correction in VFB by default.</span>

<span style="color: #333333">**VRAY_VFB_ALWAYS_ON_TOP**</span><span style="color: #333333"> - Specify an ALWAYS ON TOP behavior:</span>

**0** - disabled  
**1** - force enable always on top  
**2 **- force disable always on top


## <span style="color: #000000">**Log File**</span>

---

<span style="color: #333333">**VRAY_FOR_MAYA_LOG_FILE_NAME **</span><span style="color: #333333">– Specifies the name of the log file (vray4maya_log.txt is used if not set).</span>

<span style="color: #333333">**VRAY_FOR_MAYA_LOG_FILE_PATH**</span><span style="color: #333333"> – Specifies the path to the log file (the temp folder is used if not set).</span>

<span style="color: #333333">**VRAYSL_LOG_FILE_NAME**</span><span style="color: #333333"> </span><span style="color: #333333">**(standalone)**</span><span style="color: #333333"> – Specifies the name of the log file for DR rendering (vraysl_log.txt is used if not set).</span>

<span style="color: #333333">**VRAYSL_LOG_FILE_PATH (standalone)**</span><span style="color: #333333"> – Specifies the path to the log file for DR rendering (the temp folder is used if not set).</span>


## <span style="color: #000000">**Command Line**</span>

---

<span style="color: #333333">**VRAY_CMD_PREFIX**</span><span style="color: #333333"> </span><span style="color: #333333">**(standalone)**</span><span style="color: #333333"> – Specifies command-line options for V-Ray Standalone which are prepended to the actual command line.</span>

<span style="color: #333333">**VRAY_CMD_SUFFIX**</span><span style="color: #333333"> </span><span style="color: #000000">**(standalone)**</span><span style="color: #333333"> – Specifies command line options that are appended to the actual command line.</span>

<span style="color: #000000"> </span>

## <span style="color: #000000">**Miscellaneous**</span>

---

<span style="color: #333333">**VRAY_FOR_MAYA_VP2_BAKE_RESOLUTION**</span><span style="color: #333333"> – Because of limitations in Maya itself, V-Ray can't support textures in their native resolution like the standard Viewport 2.0 does. V-Ray must always bake the textures, and it's using the </span><span style="color: #333333">**Bake Resolution for Unsupported Texture Types**</span><span style="color: #333333"> option in the </span><span style="color: #333333">**Hardware Renderer 2.0 Settings **</span><span style="color: #333333">dialog. The default resolution there is very low (64) by default. V-Ray ignores values below </span><span style="color: #333333">*256.*</span><span style="color: #333333"> However, even this resolution is not very suitable, and forcing high resolution for all unsupported textures may be undesirable. In such case, this environment variable can be used, ignoring the Viewport 2.0 setting.</span>

<span style="color: #333333">**MAYA_ENABLE_PRE_RENDER**</span><span style="color: #333333"> – A small number of features in V-Ray require reading specific attributes for the whole animation range before the actual rendering can start. In previous versions, this required a pre-render run along the whole animation range. Latest V-Ray versions avoid this extra cost which can be significant with dynamics on the scene. If, due to bugs in Maya or V-Ray, this method fails, this will be reported, and it's still possible to use the old, slow (but proven) method.</span>

<span style="color: #333333">**VRAY_IGNORE_FIX_DARK_EDGES**</span><span style="color: #333333"> – Due to a bug in V-Ray 2.0, the </span><span style="color: #333333">**Fix dark edges**</span><span style="color: #333333"> option of the</span><span style="color: #000000"> </span><span style="color: #000000">[VRayMtl](https://docs-chaos.atlassian.net/wiki/spaces/VMAYA/pages/111739405)</span><span style="color: #000000"> </span><span style="color: #333333">didn't work. This environment variable can be used to keep compatibility with old scenes which rendered wrong.</span>

<span style="color: #333333">**VRAY_NO_BUMP_ATTENUATION**</span><span style="color: #333333"> - When set to 1, it disables the bump attenuation that was added in V-Ray 5 for all materials and produces results like V-Ray Next. Not supported when rendering with V-Ray GPU.</span>

<span style="color: #333333">**VRAY_DISABLE_DRAG_DROP_FILEEXT**</span><span style="color: #333333"> – Disables drag and drop import for file formats supported in V-Ray for Maya. Such as </span><span style="color: #333333">*ies*</span><span style="color: #333333">; </span><span style="color: #333333">*vrmesh*</span><span style="color: #333333">, </span><span style="color: #333333">*abc*</span><span style="color: #333333">; </span><span style="color: #333333">*aur*</span><span style="color: #333333">; </span><span style="color: #333333">*vdb*</span><span style="color: #333333">; </span><span style="color: #333333">*f3d*</span><span style="color: #333333">; </span><span style="color: #333333">*vrscene*</span><span style="color: #333333">; </span><span style="color: #333333">*vrlmap *</span><span style="color: #333333">files. To enter file format to be excluded, enter them in a list, separated with semicolons like so:</span>  
<span style="color: #333333">*VRAY_DISABLE_DRAG_DROP_FILEEXT=abc;vrmesh;vrscene*</span>

<span style="color: #333333">**VRAY_USD_PROVIDER**</span><span style="color: #333333"> – Specifies the USD plugin version. </span><span style="color: #272727">Starting with V-Ray 7, the default USD version used in V-Ray Standalone is changed to 0.24.08 by default, with version 0.23.11 as optional.</span><span style="color: #333333"> The possible options for this environment variable depend on the availability in the installation </span><span style="color: #333333">**vray_usd **</span><span style="color: #333333">folder. For example, </span><span style="color: #333333">*VRAY_USD_PROVIDER=0.23.11 .*</span>