I don't see any lens shader inside the material library lop, what happened to them?
More specifically where the UV lens shader? If I copy from a old file it works but it is not available right away why?
I am using build 664

The material library has a limited scope of nodes allowed, which doesn't include lens shaders. Create a matnet if you want to create a lens shader.

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.

Thanks for the feedback and help!
I found it inside the cvex context inside material library, is that not recommended?

mzigaib
Thanks for the feedback and help!
I found it inside the cvex context inside material library, is that not recommended?

the material library is not only for "storing nodes" its primary purpose is to translate shader nodes to USD. Since the lens shader is not translated to USD, the material library is not needed. The generic matnet will suffice.

Got it!
Thanks!