Copy Sop + Look at

[ParticleSkull]

Hey guys,

I have a bunch of planes on a copy sop and I need all of them to be always "looking at" the camera.

I found this topic at sidefx' forum showing how to make it at sop level (I know, at obj level it's quite easy ), but I couldn't make it work. This is what they did there:
 

Quote

Append a default Transform SOP. In the RX, RY, RZ parameters put in the following expressions:
explodematrix(dihedral(vector3(0,0,-1),vtorigin(“..”,“lookat_path”)), “SRT”, “XYZ”, “RX”)
explodematrix(dihedral(vector3(0,0,-1),vtorigin(“..”,“lookat_path”)), “SRT”, “XYZ”, “RY”)
explodematrix(dihedral(vector3(0,0,-1),vtorigin(“..”,“lookat_path”)), “SRT”, “XYZ”, “RZ”)


Substitute lookat_path with the path to the object you want to look at. You can substitute vector3(0,0,-1) with the axis that you want to align with. I picked the negative Z axis here because that's what the object-level does. Notice that “SRT” is the transform order which should match the transform order of your Transform SOP. Ditto for “XYZ” as the rotation order.

I actually don't know what to put at the "lookat_path". How can I put a path to another object, like a camera, in there?

Thank's
Alvaro
 

[Atom]

Check out F1s solution for this. There are two solutions provided. One for facing like the camera and another for facing the actual camera pivot point.

[ParticleSkull]

Hey Atom, that's awesome, it works perfectly!

Thx,

/Alvaro