llRot2Left

vector llRot2Left(rotation Rotation)

Returns the left vector defined by Rotation.

Returns the left axis represented by the Rotation.

Parameters

Rotation (rotation)

Technical Details

Return Type: vector
Energy: 10

Mathematically equivalent to:

ret = llVecNorm(<0., 1., 0.> * q);

If the rotation is known to be a unit quaternion (which object and agent rotations always are), it can be simplified as:

ret = <0., 1., 0.> * q;

For performance-critical code, direct vector multiplication can be 25-30% faster than calling llRot2Left(). If the operation is done often and at extremely fast rates, it can be advantageous to even save <0., 1., 0.> to a local or global variable and reuse it.

Examples

Move an object 5 metres forward along its own y-axis (left direction), regardless of the object’s orientation in the world. Works for both root and child prims:

default {
    touch_start(integer total_number) {
        vector v = llRot2Left(llGetLocalRot());
        llSetPos(llGetLocalPos() + v * 5);
    }
}

Notes

This function can be useful to identify the orientation of the local sagittal plane of the prim, since its y-axis is always perpendicular to this local sagittal plane.

llRot2Left

Examples

Notes

See Also