Particle ID numbers + motion blur still a problem? ugh


This has been a long time problem, and I’m still having issues with it in R20. I think I first noticed it in R16 but it may have been there longer.

It has to do with particles that have a limited lifetime, and using motion blur.

C4D assigns each particle an ID…however, when a particle dies, its ID gets assigned to a new particle when it is born.

This causes problems with motion blur.

Particle ID 33 (just a random number I’m picking for an example) is at (0, 300, 0) when it dies. On the next frame, a new particle is born at (250, 100, 200) and is given the ID 33 since it just became available.

So when rendering motion blur, C4D feeds the motion blur a vector between (0,300,0) and (250, 100, 200) which is a movement taking place over one frame.

The result?

Streaks between particles as they die/birth.

This is a problem at the core of C4D, not the renderer, because I’ve experienced it in Physical, and now in Redshift.

It may be considered a limitation, but I consider it a problem.

I’m wondering if there is any way around this?


Just don´t let them die but transfer to an unused group instead …


Interesting and clever approach! Thank you. I will try that next time.

This time around, I didn’t need the particles to die and be reborn, I was just trying to mock-up some fireflies quickly.

Once I had the time to devote to it and do it “right”, I made all the particles birth at once, (emitter set to ‘shot’) then just controlled the “flashing” with a plain effector and a field with noise in it. Works like a charm.

I also failed to mention that I’m using xparticles…but it doesn’t matter, this behavior is happening at the core level of C4D.

Nice to know there is a work-around. Thanks again!


didn´t mention as well - I´ve got hat workflow from Xparticles :slight_smile: