NotADirectoryError when exporting objects that contain special filesystem characters in the name

[rlguy]

If a simulation object is named with a special filesystem character (Ex: \ / : * ? " < > | on Windows), a NotADirectoryError Python error will be produced when beginning baking a simulation.

NotADirectoryError: [WinError 267] The directory name is invalid: 'C:\\Users\\ryanl\\AppData\\Local\\Temp\\untitled_flip_fluid_cache\\export\\Inflow:Cube'

This error happens because the addon exports object mesh data to files using the object's name. When saving files with invalid characters, the operating system will not be able to create the file and an error will be generated.

Workaround

Until this issue is fixed, a workaround is to remove all special filesystem characters from the object's name.

[rlguy]

I will likely wait for a large version update to fix this issue. Fixing this issue will make older FLIP Fluids caches unsupported which I would prefer to avoid in minor releases.

[rlguy]

This issue has been fixed! And good news: it will not cause older caches to be unsupported.

Object names will now be stored on the filesystem by slugifying the name. The name will be converted using a whitelist of characters and truncated to 48 characters:

"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-"

Characters not on the whitelist will be replaced with -.

To avoid collisions in edge cases, a 16 hexdigit hash will be appended to the end of the filename.