Hi,
I have a material which uses an animated point cloud to create a wetmap like in the attached image.

It seems that using $F in shaders does not work in a LOP environment, how can I use an animated sequence in my shader in a lop network?

your file parameter of pcopen doesn't seem to be promoted using Parameter VOP
only promoted parameters on top of Material node can be animated
that shouldnt work in Mantra either, if you are saying it doesn't work just in LOPs there is additional option on Material Library LOP saying Allow Shader Parameter Animation, but I'd assume that also needs that parameter to be promoted to Material level

Thanks, I was able to solve the problem by promoting the attribute and adding a edit properties lop node to manipulate the file attribute.