Redshift Environment Variables

The default behavior of Redshift can be further customized using several additional environment variables:

`REDSHIFT_CACHEPATH`	The Redshift disk cache path is normally defined as a system-wide preference in the preferences.xml file in the Redshift local data path. The value set in the global preferences can be overridden using the environment variable `REDSHIFT_CACHEPATH`.
`REDSHIFT_TEXTURECACHEBUDGET`	Similar to `REDSHIFT_CACHEPATH`, the `REDSHIFT_TEXTURECACHEBUDGET` variable can be used to override the values defined in the system preferences.
`REDSHIFT_MAXLOGSTOKEEP`	By default, Redshift stores the log files for the last 10 sessions. The number of log files to keep can be adjusted by setting the `REDSHIFT_MAXLOGSTOKEEP` environment variable. A negative value (e.g. -1) will prevent older log files from being automatically purged at startup.
`REDSHIFT_GPUDEVICES`	When defined, this variable overrides the which GPUs will be used for rendering (normally defined in the preferences.xml file in the Redshift local data path). Set `REDSHIFT_GPUDEVICES` to a comma-separated list of GPU ordinals. For example, `REDSHIFT_GPUDEVICES=0,1` will force the system to use GPU devices 0 and 1 for rendering. Note that this variable is read only when Redshift initializes. Any changes to the variable will only take effect after the host application is closed and relaunched.
`REDSHIFT_LICENSERETURNTIMEOUT`	Redshift always attempts to check out a license when it starts rendering a frame. By default, the license is not immediately returned when the frame finishes, but is instead kept checked out. If within 5 seconds, there is no further rendering activity, Redshift returns the license (licenses are also automatically returned when closing the host application). This timeout is configurable using the environment variable `REDSHIFT_LICENSERETURNTIMEOUT`. A negative value (e.g. -1) will cause the license to be kept checked out until the host application (Maya, etc..) shuts down. A positive value defines the timeout in seconds. Floating point values (e.g 2.5) are permitted.
`REDSHIFT_DISABLELICENSECHECKOUTONINIT`	Added in version 2.5.51 In order to display license information early, Redshift by default checks out a license at initialization (when the Redshift plugin loads in the host DCC application) and checks it back in immediately. This behavior can be disbaled by defining the environment variable `REDSHIFT_DISABLELICENSECHECKOUTONINIT`. When defined, a license will only be checked out during rendering.
`REDSHIFT_DISABLEOUTPUTLOCKFILES`	When Redshift starts rendering a frame, it writes out a `.lock` file for each output image to be rendered. These lock files are used to prevent multiple instances of Redshift from rendering to the same file concurrently. In the event that this behavior is causing problems, defining the variable `REDSHIFT_DISABLEOUTPUTLOCKFILES` will disable the use of lock files altogether.
`REDSHIFT_PATHOVERRIDE_FILE`	Added in version 2.5.61 A proxy file can contain references to other proxies, VDBs, textures, etc. If these assets are moved from their original folder locations, the proxy loader will fail to find them and load them. The `REDSHIFT_PATHOVERRIDE_FILE` environment variable can point to a text file which is used to "translate" paths from a location to a different location. The text file should contain double-quote-enclosed pairs of strings. The first string of the pair is the "from" path and the second is the "to" path. So, for example, if the environment variable is set to `REDSHIFT_PATHOVERRIDE_FILE = C:\mypathoverrides.txt` ... the file `mypathoverrides.txt` could contain the following, which helps to map from a local folder to some shared network location `"C:\MyTextures\" "\\MYSERVER01\Textures\"` `"C:\MyVDBs\" "\\MYSERVER01\VDBs\"`
`REDSHIFT_PATHOVERRIDE_STRING`	Added in version 2.5.61 This is similar to `REDSHIFT_PATHOVERRIDE_FILE`, except the environment variable itself contains the double-quote-delimited list of pairs. For example: `REDSHIFT_PATHOVERRIDE_STRING = "C:\MyTextures\" "\\MYSERVER01\Textures\" "C:\MyVDBs\" "\\MYSERVER01\VDBs\"` Please note that, if both `REDSHIFT_PATHOVERRIDE_FILE` and `REDSHIFT_PATHOVERRIDE_STRING` environment variables are defined, `REDSHIFT_PATHOVERRIDE_FILE` takes precedence
`REDSHIFT_ABORTONLICENSEFAIL`	Added in version 2.5.72 Redshift normally renders with a watermark if it fails to obtain a license. Enabling the render option Abort on License Failure in the System tab will cause Redshift to abort the frame instead of rendering with watermarks. Setting the environment variable `REDSHIFT_ABORTONLICENSEFAIL` to any value other than "0" or "FALSE" provides a system-wide alternative to enabling the Abort on License Failure render option.
`REDSHIFT_CPUAFFINITY`	Added in version 2.6.15 Allows the limiting of CPU threads. For example: `REDSHIFT_CPUAFFINITY = 2` will tell the various Redshift systems to use no more than two threads. Please note that some systems might have to use a certain number of threads onwards. Important note: When rendering with multiple GPUs, please ensure to use a value no smaller than the number of GPUs the renderer will use.
`REDSHIFT_FORCEQUITONINTERNALERROR`	Added in version 2.6.27 When set to any value other than 0, will force a hard crash when an unrecoverable error occurs while rendering
`OCIO`	Added in version 2.6.39 If a valid path is found it will override the default Display Mode to OCIO and sets the OCIO Config path to this.
`OCIO_ACTIVE_DISPLAYS`	Added in version 2.6.39 Override to only provide the given displays in the View Transform combo box.
`OCIO_ACTIVE_VIEWS`	Added in version 2.6.39 Override to only provide the given views in the View Transform combo box.
`RS_SNAPSHOT_DIR`	Added in version 2.6.42 Sets the directory snapshots are saved to. Important note: Specified directories set with Snapshot Configuration > Path take priority.
`RS_PRESET_DIR`	Added in version 2.6.44 Sets the directory to load post effect presets. The directory should contain folders for each post effect to correctly load by user defined defaults.
`REDSHIFT_TEXTUREFILELOCKINGDISABLED`	Added in version 2.6.48 Disables texture file locking; this can help improve performance on Operating Systems that have slow file locking mechanisms, for when textures have been pre-converted and are not going to be copied to the local cache.
`REDSHIFT_FILESTREAMBUFFERSIZE`	Added in version 3.0.28 Sets the minimum number of KBytes Redshift will read from a filestream during file access. The default setting is "16" which means Redshift will read a file in chunks of 16KB. Larger values like 64, 256 or even 1024 might help with network file access performance for certain networks. Larger values, though, also mean that Redshift can "overfetch" data which could have an adverse performance effect. We, therefore, recommend using this env variable only if you encounter considerable network file performance issues.