Chris Rydalch

I would look into how you're launching husk, as these search paths should always be setup internally. There isn't any env var you need to set. If you can repro the problem with a vanilla, basic setup, please log a bug for it. Thanks!

Paths that use $HFS (and $HH is the same as $HFS/houdini), are turned into 'search paths'; you can recognize search paths because they don't start with a period, slash, or drive letter. This was done intentionally to avoid making fragile absolute or relative paths that point to things that ship with Houdini. Houdini automatically adds $HFS as a search path, so it can find these assets automatically.

Sorry for the confusion. The Material Library's tab menu is filtered to avoid the overwhelming users with too many incompatible options when building their materials, which is why lens shaders are hidden from the tab menu. You can also put lens shaders in `/mat`, make a new Material Network (i.e. `matnet`) in your LOP Network, or make a VEX Material Builder in the Material Library LOP, and create lens shaders in there. If you really want the massive, unfiltered VOP tab menu, you can clear-out the Tab Menu Mask parm on the Material Library LOP.

Lens shaders don't get converted to USD like other materials, so they don't require a connected material library node. When the Camera LOP cooks, that node does the authoring/copying of VEX code. This setup is related to why lens shaders can't really be animated, like other materials in USD. We're working to improve lens shader authoring/workflows for future releases.