Instead of p@orient, I can combine Copytopoint nodes and adjust the rotation value with 3@transform.
But I'm a little confused that I find nothing with 3@transform in official manual,
Is it an attribute defined as a houdini known type?
matrix3 m = ident(); rotate(m, radians(chf("angel")), set(0,1,0)); 3@transform = m; //p@orient = quaternion(m);