Get particles nearest to camera

[xenas]

What is the best way that I can group/ split particles that are nearest to the camera (to a distance) and have it isolated from the other particles, other than selecting and checking manually each and every particle?

I asked as I am doing sparks in which some of the sparks/ particles got real close to the camera which results them in being very big

[Atom]

You could just parent a box or cone to the camera. Then use it to create a group for particles that fall within that boundary/area. Apply a @pscale multiplier to the particles that reside within that group to keep them from getting too large.

@pscale *=0.5;

 

[jkunz07]

You can use the uv texture SOP to project uv's from your camera.  The Z component of the uv will be the particle's distance from your camera.

You can then use that in an attribute create SOP, wrangle, etc. when creating pscale so that the particles are larger when further from the camera.

You can also use these uvs to group or delete particles which are too close or far from your camera or outside the frustum.

pscale_from_camera_distance.v1.hipnc

Edited May 18, 2018 by jkunz07