Split particles on collision frame only

[thomwickes]

Hey I'm trying to split particles on collision but only on the frame they collide on - the only way I can do this now is by killing the original particle, or by turning off 'preserve group' for the collision group that the split pop sources from. I need preserve group checked on as I'm using the collided particles elsewhere in my scene.

Is there a simple expression that I could put in the activation of the split pop that just emits on the actual frame of impact?

Edited December 14, 2011 by thomwickes

[rafaelfs]

Hey I'm trying to split particles on collision but only on the frame they collide on - the only way I can do this now is by killing the original particle, or by turning off 'preserve group' for the collision group that the split pop sources from.

Is there a simple expression that I could put in the activation of the split pop that just emits on the actual frame of impact?

You can set the first collision behavior as "Die on Collision" and at the same time you create a collision group by entering a name in the Collision Group field (leave the "preserve group" option unchecked).

Place a Split POP and set the Source Group as the collision group you created and you're set!

Cheers

[thomwickes]

You can set the first collision behavior as "Die on Collision" and at the same time you create a collision group by entering a name in the Collision Group field (leave the "preserve group" option unchecked).

Place a Split POP and set the Source Group as the collision group you created and you're set!

Cheers

Thanks but I need to do this without killing the original particle as I'm using the collision attributes (num hit, hit id, hit time, etc) from the original particle elsewhere in my scene.

[ryew]

Will setting a collision group and collision event on the collide POP to be referenced in the split POP like in the attached file accomplish what you are after?

splittingParticleOnCollide01.hipnc

[thomwickes]

Will setting a collision group and collision event on the collide POP to be referenced in the split POP like in the attached file accomplish what you are after?

Ah not quite - I'd already tried this. I need 'preserve group' checked on as I use the collided particles elsewhere

edit: just realised i'd not made this clear in the OP. I've just updated it

Edited December 14, 2011 by thomwickes

[thomwickes]

Ok, I worked it out. I created a group just above my split with the rule "$JUSTHIT == 1"

I then used this group to split from. This will only emit particles as they collide as the $JUSTHIT variable is cleared at the beginning of each timestep

[rafaelfs]

Ok, I worked it out. I created a group just above my split with the rule "$JUSTHIT == 1"

I then used this group to split from. This will only emit particles as they collide as the $JUSTHIT variable is cleared at the beginning of each timestep

You could also have used that same setup I talked about just change the collision behavior to "Continue on course".

Cheers

Edited December 14, 2011 by rafaelfs

[thomwickes]

You could also have used that same setup I talked about just change the collision behavior to not kill the particles.

Cheers

I needed "preserve group" checked on though. With preserve group checked on, and the particles staying alive, they will be constantly emitting.

[ryew]

Ah not quite - I'd already tried this. I need 'preserve group' checked on as I use the collided particles elsewhere

edit: just realised i'd not made this clear in the OP. I've just updated it

No problem, glad to hear you hit upon a solution