How to randomize size of "Particles As Primitives" in Procedural system?


I’m using the Procedural Generators “Particles As Primitives”.
I would like to be able to randomize the Generated Primitive Size at birth and/or through an affector.

Changing the size at the level of the particle system does not seem to give anything and unlike the “Procedural Particles” node there is no Size Randomness parameter.

Also, the size of the primitives thus generated (as you can see here : Notch Streams EP09: Getting to know your Procedurals - YouTube ) evolve from zero to one (grow) at birth and from one to zero (shrink) at death of the particle without being able to parameterize this behavior.

How can we control the size in these situations?

Currently that node doesn’t have a property for size randomness, but I do like the idea. I’ll talk to the dev team about it.

In the mean time, you would need to use the procedural particles node, or build a particles + cloning system with the geometry you want, then bring it back into the procedural with combine geometry and a procedural 3D object. less efficient, but can be optimised a bit.

– Ryan

Hi Ryan,
Thank you for your answer and for the solution.
It works, although as you might expect since we now need to check Animate SDF, it is relatively inefficient. In terms of FPS, it’s no more realtime, so to speak. There are few particles (about a dozen), but the Smooth-Union SDF is done with another 3D Object procedural which is rather greedy.

I also think that adding the parameter would be worth it.