How would I freeze particles?

Hi. I'm trying to make a test where bunch of particles fly up, and then freeze in mid-air, but I can't seem to get it right. I tried messing with the speed in the Lifetime Controls, but I can't get the stuff to freeze how I want them. For example in my Ground Crumble test, how would I get all the concrete to fly up, and then freeze all at the same time, at the exact frame I want them to freeze. Thanks!

• Staff
Seesm like the Lifetime graph should handle this, lemme take a look and get back to you.
• Thanks sir!
• Staff
OK, I was experimenting with re-creating your nifty effect here, and adding a stop, and the reason the Lifetime graph doesn't stop things like you expect is because the Force is still active, pulling on the particles, so even though they have no speed of their own, the force is causing them to continue moving.
Try keyframing the Lifetime Speed, without any forces applied, and I think you'll get the stopping effect you are after. So, if you keyframe the force to 0 at the exact frame where your Lifetime graph stops the effect, I think you can get the results you are after.
• Ok I'll give it a try. I usually have to estimate when it comes to the Lifetime graph, is there a way to be more exact? Thanks.
• Staff
Well, the Lifetime keyframe positions are all percentages, so you can mathematically calculate things out based on the particle life that you have set. If your particle life is 10 seconds, for example, then its easy: 40% is 4 seconds in, 70% is 7 seconds in, etc. If your project is at 30 fps, then its easy, too, as each cent would then be three frames, so 25% would be 2:15, and 53% would be 5:09.
The exact math will depend on the framerate and particle life you have chosen, but it can be calculated out to some extent. Good thing we all took math in school, eh?
• More like good thing there's a calculator on my computer
• Staff
Heh, also that.