Following happens when i put a sphere in a box (without contact between)
and connect the sphere with particles input 1 and sphere with input 2.
When i select “geometry” as behavior and “stick on contact” particles (deformations) react on limits as expected.
when i switch to “die on contact” they do as well but with a much smaller amplitude of the
deformations. (as if “stick” has an additional attractor effect).
when i switch to "particles as behaviour, the sphere emits particles in the opposite direction as well - and these particles ignore the liming box.
“Bounce mode” (if collide) ignores all borders in geometry and as particles as well
Further on: The particles stream in both behaviors dies from time to time
and:
node viewer shows box as purple limit lines, but the limit parameters aren’t changing (so intended)?
Generally, I find that these sorts of issues are easier to communicate if you post a sample network as well. The particle SOP has lots of parameters and it can be difficult for someone else to recreate the same misbehavior you might be seeing without a solid reference point.
I think I’ve followed what you’ve described, but please look to see if these are consistent with what you’re seeing.
I can see a strange behavior with behavior set to modify source, and hit behavior set to stick on contact. I see the expected behavior the first time looping through points, but not in subsequent loops.
I’m not seeing particle emission in the opposite direction.
Can you say more about what you mean by: “the particle stream in both behaviors dies from time to time?”
The limit plane and the collision input have a different effect on the particle system. So far as I know, there is not a way to visualize the limit plane. Changing that parameter will alter the behavior of the particles, but there isn’t a good visual representation of what that looks like. base_particle_behavior.tox (1.22 KB)
I think part of what’s happening here is related to your use of bezier surfaces as an emitter for your particles. Particles are seeded with starting locations at the verts (I think it’s verts not points, but it might be points not verts) of a piece of source geometry, with the normal representing the vector for particle emission. That’s very clean for meshes and polygons, but less clear when dealing with besier and nurbs surfaces since their shape is described by control points that drive a spline.
That’s not to say that you shouldn’t use besier or nurbs surfaces to drive a particle system, but rather that doing so is likely to generate unexpected / inconsistent results from what you’re expecting.
I think i found the main problem with the particles behavior. It is independent from the primitive type and occurs always, when mass <1. (Which is necessary to get lines instead of singles particles. )
I would’nt be surprised if this causes also the different amplitudes in geometry mode due to “die” or “stick” as described in my first post in this thread.