View Full Version : Mel expression - PP procedural animation

12 December 2011, 06:05 PM
Hi, First post on here - hope its in the right place.

I'm looking (to begin with) to simply create a PP expression that can make a particle move in
a straight line (with no end point) just continuous forward motion. I have no idea where to begin
as i've never used a PP for specific motion (only rand motion using sin etc)

This is the first step and a long as i can get this to work eventually i would like to make the expression to allow the particle to gradually curve etc.

Any help or advice anyone could give would be greatly appreciated


12 December 2011, 01:29 PM
Well, you can give the particles a velocity in a certain direction with something like:

velocity = <<1,0,0>>;

Or you place them manually in the predynamics script:

vector $p=position;
float $speed = .1;
position = <<$p.x + $speed , $p.y, $p.z>>;

12 December 2011, 03:22 PM
Yeah thats just what i was after - but what would i do if i wanted to make it slowly curve (without using an acutal curve) is it possible?

12 December 2011, 07:30 PM
Just add a smaller amount to the Y or Z components (smaller to make the curve gradual). That will give it a circular path, the smaller the increments, the larger the radius.

If you want more complex curves, you need a more complex equation.

<* Wes *>

12 December 2011, 03:06 PM
but wont just reducing the amount in the velocity make it move slower in a linear direction? do i need a different pp or expression to make the particle curve?

12 December 2011, 07:34 PM

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