forcePop mix velocity?

[MENOZ]

hello!

there is something that i don't understand in pop networks.

I emit particles from my object, add a vop network with a noise into the velocity, add a force.

so the order is: source, VopPop, force.

Why the velocity that comes out from the VopPop is not added or overridden by the force?

if i change the order to source, force, VopPop the result is the same, but here i can think that the VopPop override the velocity attribute that comes from the force..

now i go in the VopPop network and mix the noise with the global variable V.

Ok, it works, the velocities are blended and i can adjust the bias.

the order now is: source, force, VopPop.

so the VopPop takes the velocity that comes from the force and mix with his noise velocity.

now i change the order again. source, VopPop, force.

if i see the result of my vopPop and change the bias value i can see that it mix between zero velocity(from source) and noise velocity, as it should, but if i see the force the force velocity and the noise velocity are now blended.

why?

how does it works? the VopPop mix the velocity of the source, it should't take care of what's happen after..

I hope you understand.. maybe i post a hip.

vopPop_mix.hipnc

Edited April 20, 2009 by MENOZ

[stevenong]

When writing a VOP POP, you should be using acceleration to push particles instead of overriding velocity. What forces in POPs do is to push particles along (using acceleration) and not override velocity.

With your setup, your VOP POP sets the velocity values & the Force POP is trying to modify it. Note that POPs is iterative so it can only process what's calculated before.

Cheers!

steven

[MENOZ]

When writing a VOP POP, you should be using acceleration to push particles instead of overriding velocity. What forces in POPs do is to push particles along (using acceleration) and not override velocity.

With your setup, your VOP POP sets the velocity values & the Force POP is trying to modify it. Note that POPs is iterative so it can only process what's calculated before.

Cheers!

steven

in my setup the velocity is updated at each frame, so it's difficult for the force modify it using acceleration. ok i didn't know what the force modify, the vellocity or the acceleration now i understood this part.. thanks!

but if the vop pop would set the velocity equal to zero, the force pop should have no effect because the velocity is updated at each frame by the vop pop. it

[stevenong]

If you want to override the velocity, the VOP POP should be the last POP.

Cheers!

steven