Hi, I'm wondering how to create projector rays and light trails in houdini?
I'm trying to use particle, but the result isn't ideal.

Hi,
I think you have to use a volume in the renderer to absorb the light in the atmosphere to achieve the desired effect. Maybe it could also work with alpha maps, I think it was realized like that in video games in the past. What you are looking for is often called God Rays, maybe you can find more under that term; or Volumetric lighting in general.