Creating a particle beam on mulitple layers and in X,Y,Z space
by Peter Gagnon
on
Jan 17, 2008 at 3:12:05 pm
Hi All,
I have created a particle beam effect for a 8 second Sci Fi gun battle. I want to keep the same effect for all the various guns and manipulate the beam in 3D space so that I can go from the muzzle of the weapon to where ever it's going. The beam consists of several layers, but the beam itself is a combination between trapcode particular and 3D stroke... I don't want this effect to look like 'Star Wars' so I could really use some ideas... I though about using a null to control the positions with an expression, etc... but I can never fully get this to work... Any ideas?
Re: Creating a particle beam on mulitple layers and in X,Y,Z space by Darby Edelen on Jan 17, 2008 at 4:36:02 pm
[Peter Gagnon]"I though about using a null to control the positions with an expression, etc... but I can never fully get this to work... Any ideas?"
I don't have enough experience with 3D Stroke to give you a solution for that effect, but you should be able to do something like this with Particular. I'd even suggest using 2 Nulls, one for the source and one for the destination. Then you could interpolate the position of the emitter from one to the other between layer markers.
in = thisComp.layer("Muzzle");
out = thisComp.layer("Destination");
try{
i = marker.index(1).time;
o = marker.index(2).time;
}
catch(myErr){
i = inPoint;
o = outPoint;
}
linear(time, i, o, in, out);
A couple of notes: this attempts to use the first two markers on the layer as the start and end times for the shot, if one of these 2 markers doesn't exist then it uses the layer in point as the start time and the out point as the end time. Also, this returns a three dimensional vector if the Nulls (Muzzle & Destination) are 3D layers, so you'll need to split the result into X & Y and Z values for Particular:
p = linear(time, i, o, in, out);
p[0,1]
and
p = linear(time, i, o, in, out);
p[2]
Should work pretty well though.
Darby Edelen Designer Left Coast Digital Santa Cruz, CA
Re: Creating a particle beam on mulitple layers and in X,Y,Z space by Peter Gagnon on Jan 17, 2008 at 4:45:35 pm
Wow! That's cool... I am still trying to wrap my head around it... I guess the destination null is what is confusing me. I am gonna d a test now... thanks.
