From Second Life Wiki
Euler2Rot
llEuler2Rot
Function: rotation llEuler2Rot( vector v );
Returns a rotation representation of Euler Angles v.
Specification
The Euler angle vector (in radians) is converted to a rotation by doing the rotations around the 3 axes in Z, Y, X order. So llEuler2Rot(<1.0, 2.0, 3.0> * DEG_TO_RAD) generates a rotation by taking a vector pointing along the X axis, first rotating it 3 degrees around the global Z axis, then rotating the resulting vector 2 degrees around the global Y axis, and finally rotating that 1 degree around the global X axis.