Houdini handles filenames beginning with temp: and uses the operating system’s temporary file services to manage them.
Overview
The temp: file handler uses operating system calls to create temporary files. These files persistent only while the process that created them is active and are automatically cleaned up afterward. This can be convenient for generated files such as textures and shadow maps that you don’t need to cache between renders.
For example:
temp:shadow_$F.rat
Note
Depending on the operating system, temp: files may not show up in any directory listing or file search, or be flushed to disk at all.
Important note
Please note that a temp: file is useless for sharing files between processes, because it can’t be used by any process other than the one that created it.
For example, you can’t use temp: files for photon mapping since pre-filtering requires a separate process to read/write the raw photons.
Details
Houdini asks the operating system to open temporary files in
$HOUDINI_TEMP_DIR.On Windows, Houdini opens the files with the flags
w+bTD.