Inheriting velocity when using "Impulse Actication" with POP S

[kursad]

Hi

I am trying to use POP SOP with impulse activation set to "$FF==1" only. I am using a trail sop to create velocity prior to POP SOP. Now if I activate my particles only on frame 1 as in the expression, the velocity information is not passed to the existing particles. They pretty much stay static. If I make Impulse Activation to "True" at all times then the velocity activation calculated properly.

Is there a way to make have the velocity and the position information calculated properly at all frames while I set my "Impulse Activation" to "$FF==1". I have a morphing underlying mesh.

Edit:

In a way I understand the first part of the problem I think. The Trail SOP does not naturally calculate the velocity on the first frame. So creating particles couple frames later does bring the velocity. On the other hand how can I make sure that I can bring all the velocity information that is processed by the Trail SOP at all frames? Is there such thing possible? At least I want to be able use that external velocity information to influence the particles

Edited January 11, 2011 by kursad

[Rudinie]

Did you try to tick the Accurate Births? This might help.

Kind regards,

Rudi

[SpencerL]

You could put down a timeblend SOP after your trail SOP and set the "Hold First Frame" parameter to 2. That way your v will exist at frame 1.

Be careful of using the Accurate Births option as that can drastically slow down your pop sim.

Hi

I am trying to use POP SOP with impulse activation set to "$FF==1" only. I am using a trail sop to create velocity prior to POP SOP. Now if I activate my particles only on frame 1 as in the expression, the velocity information is not passed to the existing particles. They pretty much stay static. If I make Impulse Activation to "True" at all times then the velocity activation calculated properly.

Is there a way to make have the velocity and the position information calculated properly at all frames while I set my "Impulse Activation" to "$FF==1". I have a morphing underlying mesh.

Edit:

In a way I understand the first part of the problem I think. The Trail SOP does not naturally calculate the velocity on the first frame. So creating particles couple frames later does bring the velocity. On the other hand how can I make sure that I can bring all the velocity information that is processed by the Trail SOP at all frames? Is there such thing possible? At least I want to be able use that external velocity information to influence the particles

Edited January 11, 2011 by SpencerL