-I am looking for an easy way to rotate a particle locally in VOPS. In Softimage there is a compound called "Transform Local" that allows all local transforms.

- Softimage also has a "Rotate Vector" node that allows you to rotate a particle around a vector, which really just moves the particle to the rotated position but keeps the particles orientation. I am also wondering if Houdini has a simple solution for that.

thanks

and in qLib set's of plugs you have also nice examples

And this maybe.

jamination
-I am looking for an easy way to rotate a particle locally in VOPS. In Softimage there is a compound called "Transform Local" that allows all local transforms.

it really depends on how you are representing rotation on particle, whether, v@v and v@up, v@N and v@up, p@orient, or 3@transform

in case of quaternion p@orient you can use Quaternion Multiply VOP, qmultiply() in VEX to rotate quaternion B by quaternion A, so B is the local one

in case of 3@transform, you can directly use Multiply VOP, * in VEX, to rotate matrix A by matrix B, in which case A is the local one

jamination
- Softimage also has a "Rotate Vector" node that allows you to rotate a particle around a vector, which really just moves the particle to the rotated position but keeps the particles orientation. I am also wondering if Houdini has a simple solution for that.

again, just multiply your vector by matrix using Multiply VOP or by quaternion using Rotate By Quaternion VOP ( qrotate() in VEX )