Per Particle Aim Constraint For Instanced Object

[_tmelt]

Hi,

I am struggling to find a script that will allow me to put an aim constraint on my instanced objects that are attached to a particle field. I need them to all aim at a locater. I'm assuming I'll need an expression to apply on a per particle basis, but have had no luck so far. Any help would be greatly appreciated.

Thanks in advance.

[chartt]

Hello,

You might be able to aim "instance particles" not sure if this is what you are after as you mention a field. Not sure how to go about that - however:

Now if you have a particle system that is travelling around and is affected by said particle field you can create your instance objects where the transformation of each can be snapped to each particle. Then using the aim constraint for each instance to the locator you want them to look at.

Expressions for each object to snap to the particle:

[codebox]
//get particle id:0 's position
float $instPos[] = getParticleAttr -at position swp.pt[0];
inst_object_01.translateX = $instPos[0];
inst_object_01.translateY = $instPos[1];
inst_object_01.translateZ = $instPos[2];
[/codebox]

Then add the aim constraint.

You could MEL script this for each of the instance object and then your job would be easier.

Hope that gets you going.

Chris

[visualfx]

Add a per particle vector attribute, name it something like "aimPositionPP".
Setup your particle expression like this...(I'm assuming the locator is "locator1" and your particleShape is "particleShape1")

CODE
particleShape1.aimPositionPP = <>;

Now go to the Instancer (Geometry Replacement) tab in the attribute editor for your particle shape. Under the Rotation Options set Aim Position to aimPositionPP.

Depending on your requirements, you may need to specifiy an aim up vector. But this should at least point you in the right direction . . . no pun intended