I have a Possible and Plausible Fix for Rain and Particle FX (Cascade, Generate Mesh Distance Fields On.)
Rather than use Mesh Distance Fields alone, could a user-set tick be built into the Cascade with a Node, the node would capture the image’(s) alpha mask, and use internal code to verify geometry collision (Static Mesh, with Alphas; BSP.) Of course with analysis of the image(s) you could stop kill or bounce the particles with a high probability of negating erroneous indoor behavior with image alpha mask captures stopping large sprites with high number of tiles on material to still be properly displayed because of the alpha mask’s geometry detection.
Thusly the Capture Alpha Mask UV Rendering Node would make indoor rain and snow ultimately more effective if geometry is identified properly, with the preview of the masking computed and the bonus is rain sd snow would be using very large scaled sprites, with UV tiling at high numbers, but indoor detection would be like magic.
Thanks, Good luck to make this if you would please.