It’s not exactly particles being emitted by other particles as objects are used as a link to instance other particles, but it’s the idea.
I’ve made a quick example here with two scenes.
Scene 1 is a basic example showing how the setup works.
I set a semi-sphere (base) to emit 10 particles represented by torus object (obj1) which each emit 20 child suzanne (obj2) after frame 10.
Things to look at are:
- particle render settings for base and obj1, set to None
- emission settings for obj1:
- notice 200 for particle number, meaning 20 particles per obj1 instance
- Use Modifier Stack checked)
- modifier stack for obj1 and obj2:
- particle instance must be applied before particle system
- obj2 has unborn and dead unchecked (play around with those to see what they do)
Once you’ve understood that setup you can move to the second scene which explains the substep problem I stated above. It’s a simple firework example, but a bit more complicated than the first scene. A plane (base) shoots one particle (obj1) to the air that then explodes in multiple fragments (obj2). Each obj2 then emits a trail of particles.
As always things to look at are Particle Emission and Render settings for each object (including obj2 this time).
You’ll see however when you run the simulation that obj2 particles are emitted each frame. Every frame, several particles are emitted, then obj2 moves, and on the next frame another pack of particles are emitted, with nothing between these frames. This results in a blotchy simulation where particles aren’t emitted continuously, and ends up in bad unwanted results.
Unfortunately tweaking the subframe value in the particle settings (physics tab) doesn’t change anything. This is a known problem and I’ve read on developper.blender.org that the whole particle system has to be kind of rewritten to solve this issue…
The only workaround I can think of right now is to play around with the timestep or time remapping option, but it seems quite tedious and difficult to include in a scene where other objects are animated.
If anyone finds a working solution to this I’d be happy to hear about it !
EDIT: I managed to upload the first example, second seems to be too heavy for upload so here’s a link
The particles aren’t baked in any file to save memory.
scene1 Simple setup.blend (754 KB)