Rotating Headaches

I am trying to get a child prim to rotate around an arbitrary axis fed by another script in a linkset. I generally do pretty well at math, but for some reason rotations drive me NUTS. I can get the following code to work as long as all prims in the linkset have zero rotation. But as soon as I rotate the one this code is in, it seems to have a completely different axis. I'm obviously not taking into account the local rotation correctly, but I just cannot figure out how to do it right! Any help out there?

This code is loosely based on something posted awhile back by Joannah Cramer, /54/87/134397/1.html

rotate( rotation Spin )
{

	vector newPos = ( llGetLocalPos() - offset ) * Spin;
	llSetPrimitiveParams( [ PRIM_POSITION, offset + newPos, PRIM_ROTATION, llGetRot() * Spin ] );
}

move(vector offset)
{
	offset = offset - llGetLocalPos();

	rotation spin;
	integer i;
	if (!bOpen)
	{
		vBase = llGetLocalPos();
		rBase = llGetLocalRot();
		spin = llAxisAngle2Rot( <0.0, 0.0, 1.0> , (9 * DEG_TO_RAD) ); // rotate in 10 steps on (local) Z axis
		for( i = 0; i < 10; ++i )
		{
			rotate( spin );
		}

	} else
	if (bOpen)
	{
		spin = llAxisAngle2Rot( <0.0, 0.0, 1.0>, (-9 * DEG_TO_RAD) ); // rotate back
		for( i = 0; i < 10; ++i )
		{
			rotate( spin );
		}
		llSetPos(vBase);
		llSetLocalRot(rBase);
	}
	bOpen = !bOpen;
}

Unfortunately that's what happens using llSetPrimitiveParams on child prims. You have to resort to using only llSetLocalRot.

S

jira actricle SVC-93 bites again... the workarounds for set prim params can be found at https://jira.secondlife.com/browse/SVC-93

Wow. I ran into this way back when I first joined SL (and it had already been reported then). Weeeeeee! You'd think it would be a little higher on the priority list.

it's been mostly ignored, because people have built a lot of content that would break relying on the current behavior, and apparently no one wants to code a replacement function to legacy the old one

Grrrr. I'd do it. I've had plenty of vector mathematics, and it's the fun stuff. Hmph.