How Arnold handles paths
When you render a frame, here's what Arnold does for file paths:
Replace backslashes
When Arnold loads an ass file, Arnold replaces all backslashes ( \ ) with forward slashes ( / )
Expand environment variables
When Arnold uses a parameter, Arnold expands all environment variable references, which look like this: [MY_TEXTURE_PATH]
Map paths
After Arnold expands environment variables, Arnold applies the path-mapping rules specified by the Arnold pathmap file.
Arnold expands environment variable expansion and maps paths for:
- search paths in the options node
- filename parameters for these nodes:
- alembic
- all driver nodes such as driver_deepexr, driver_exr, driver_jpg, driver_png, and driver_tiff
- image
- include_graph
- materialx
- photometric_light
- procedural
- volume
- volume_implicit
Setting up path mapping
You can automatically remap paths at render time using a pathmap file.
To use a pathmap
- Set the ARNOLD_PATHMAP environment variable to point a pathmap file
The pathmap file is a json file. For example:
Path mapping uses regular expressions. The general format of an entry is this:
For example, this pathmap replaces all drive mappings like E:/ and S:/ with //SERVER/
Arnold converts backslashes ( \ ) to forward slashes ( / ) when it loads the ASS file.
Path mapping happens after that, so pathmaps never have to deal with backslashes.
There can be multiple mappings for each OS: