I am trying to create an effect where just the edges of my object with respect to the camera emit particles. I can delete by normals to get just the edges, but I am looking to get a smooth falloff to drive particle emission.

I am trying to color my points based on their orientation to the camera and then use the point colors to drive the particle emission rate. I can see how this is done in a shader context, but in geometry context I am not sure how to calculate the point normals with respect to the camera.

Any ideas or other methods of doing this?

Hi aswaab. By knowing how to do this in the shading context, you're pretty much all the way there. You can use the same tools.

I attached a simple example with a VOP SOP. The only part which I think is not self explanatory is getting the camera position into VOPs. You can do this with a Parameter VOP of Vector type with the Translate Parameter of the camera referenced into it.

Good luck dude.

Thanks for putting that together, Brian. I'll have a look and see if it all makes sense.