PFlow help needed. Grow for and fade for - like superspray

[Morne]

Hi all

I'm revisiting a bunch of old projects and tweaking things a bit. I'm a bit rusty on one or two things. In superspray with facing particles I can have a particle "grow for x frames" then live and after that "fade for x frames". I don't see this in Pflow. Best I can see is the particle just appears, and at time of death just dies.

don't tell me this is going to be another one of those "duh" moments

[joconnell]

Okay - so with pflow what you do for both of these things you've got to animate a scale operator. If you want every particle to have the same grow, normal and shrink timings all the time, what you do is animate a scale op from FRAME 0, starting with a scale of 0 and scaling up to the amount you want (lets say 100 percent) at the frame you want the scaling to finish by. Then say you want your particles to stay normal until 75 frames and scale back down, copy your 100% scale key til frame 75 and then set another key at frame 100 with a scale of 0%. So Particle flow will look at all the particles in the event with the scale operator and start using your scaling. What you want to look at next is the "sync by" options. If you use absolute time, it means that all your particles will use the exact frames you've set in your scale operator. So say your scale has a value of 50% at frame 12, every particle will be 50% scale at frame 12 and so on. If you use particle age, what pflow will do is as soon as your particle is born, it'll take the animation in your scale op and slide the animation curve to the frame that your particle is born on. So a particle born at frame 30 will use your full scale up and scale down animation. Lastly you have event duration which is very handy. With this what it does is when a particle enters the event, that becomes the first frame of the animation you've set up. So say if a particle enters and event with your scale animation, just as it enters that event it'll do the full scale up and scale down animation.

Might be a slightly bad explanation so lets do a quick example.

Make a particle flow system with a starting event, an animated scale (animate your scale start at frame 0 with a scale of 0% and at frame 25 scale at 100%) - put in an age test in this event set to a particle age of 25.
Make a second event with nothing really in it, aside from another age test this time set to event age and a value of 50 - this means the particles will hang around in this event for 50 frames then move on. Connect the age test from event 1 into the input of event 2.
Make a third and final event with another scale animation. Again starting at frame zero, this time animate from 100% at frame 0 to 0% at frame 25. Set the "sync by" on this to event age. Take the output of the age test in event 2, feed it into the input of event 3.

What you should get is particles that grow up over 25 frames, stay the same size for 50 frames, then shrink down over 25 frames.