Well, nice try XingBat
You are using exactly the same code as chronocide -

No, actually he's provided a more complete package of functions for rotating an object.

LocalToParent involves two objects. We're just working with a single, spinning object here. So only a couple lines of code are needed, and I think xing pretty much summed up the possible single-spinning-object variations.

You're adding a cube, and void LocalToParent(int PARENT, int OBJ, Vector3 rotation, Vector3 translation){
Vector3 parentLocation;
Quaternion parentOrientation;
Quaternion newOrientation;
Quaternion objectOrientation;
Vector3 forward, location, newLocation;
float x,y,z,ud,lr,fb;
x = rotation.x; y = rotation.y; z = rotation.z;
fb = translation.z; lr = translation.x; ud = translation.y;
iObjectLocation(PARENT, parentLocation);
iObjectOrientation(PARENT,parentOrientation);
iObjectOrientationSet(OBJ,parentOrientation);
iVectorRotate(forward,Vector3(lr,ud,fb),parentOrientation);
newLocation = parentLocation + forward;
iObjectLocationSet(OBJ,newLocation);
iQuaternionFromEulerAngles(newOrientation,x,y,z,"xyz");
iQuaternionMultiply(newOrientation,newOrientation,parentOrientation);
iObjectOrientationSet(OBJ,newOrientation);
}
to do this
iQuaternionFromEulerAngles(q,0,f,0,"xyz");   iObjectOrientationSet(OBJ_0,q);-oh, right, local - then also needed is iQuaternionMultiply and iObjectOrientation
For a relative position, like LocalToParent provides, iVectorRotate, using the new orientation and desired offset vector

If you'd be adding a script and another object to rotate an object, you might as well use a Transform object.

I'm not going to get into an argument again, it's really not worth wasting time on.

chronocide and fourdee seem to be the only ones to understand the underlying maths around quaternions. chronocide based on his excellent comprehension of quaternions not being cumulative, and fourdee for his own very implementation of quaternions in his Tron game. Using someone else's functions does not mean you understand them, only that one knows how to use them.

Some don't even bother to read the code, and make a judgment call on "hearsay".

LocalToParent is excellent, but is designed for local translation and rotation. (Parent/Child relationships included). My functions don't aim to replace it, but rather to simply offer extra functions to help make life easier for those who do not understand quaternions or how to apply them. If anyone wishes to use them, then by all means do. If not; then who cares.

Rotataternions are my idea of a play on words on Quaternion. A little joke that seems to fly over most folks heads, and misread it as bragging. No loss.

@XingBatty...

chronocide and fourdee seem to be the only ones to understand the underlying maths around quaternions

AHAHAHAHAHAHAAAAAAAA!!!!  i'm sorry kid... but you're just plain delusional...

second...

you, and anyone who chooses to use your magnificent cure all functions, will eventually run into the same problems that those who actually know what they're talking about have discovered months... no, make that years ago... 

your functions dependence on iQuaternionFromEulerAngles() guarantees this...

but you keep on floating around in your world of make believe... thinking that you're the only one here who "understands the underlying maths around quaternions"...

@Chronicide...
ok... then, like i said above... do it whichever way you want...  i really could care less  which way you choose...

I was referring to the Transform object, not the iObjectChildTransform function.

i know you were referring to the transform object... read what i said again, s  l  o  w  l  y....

jeeeeez.. you two geniuses... it's is like the blind leading the blind...



--Mike

iQuaternionTo and From Euler angles is buggy... i think that that was settled upon a looong time ago...

and where do you see me fighting with em... i already said twice above that they're free to do whatever they wish...  i'm merely trying to pointout to them that they could use your LocalToParent() function and avoid all the issues that dealing with quaternions raises in RAD...

btw..

what's the problem over at the foundry... nothing permanent i hope...

--Mike

your functions dependence on iQuaternionFromEulerAngles() guarantees this...

You've overlooked the fact that LocalToParent also depends on iQuaternionFromEulerAngles:void LocalToParent(int PARENT, int OBJ, Vector3 rotation, Vector3 translation){
Vector3 parentLocation;
Quaternion parentOrientation;
Quaternion newOrientation;
Quaternion objectOrientation;
Vector3 forward, location, newLocation;
float x,y,z,ud,lr,fb;
x = rotation.x; y = rotation.y; z = rotation.z;
fb = translation.z; lr = translation.x; ud = translation.y;
iObjectLocation(PARENT, parentLocation);
iObjectOrientation(PARENT,parentOrientation);
iObjectOrientationSet(OBJ,parentOrientation);
iVectorRotate(forward,Vector3(lr,ud,fb),parentOrientation);
newLocation = parentLocation + forward;
iObjectLocationSet(OBJ,newLocation);

iQuaternionFromEulerAngles(newOrientation,x,y,z,"xyz"); // <=- <=- <=-

iQuaternionMultiply(newOrientation,newOrientation,parentOrientation);
iObjectOrientationSet(OBJ,newOrientation);
}So, in what way has it been established that iQuaternion*EulerAngles is buggy? Personally, I suspect improper usage, as it's easy to confuse eulers with direction vectors.

i'm merely trying to pointout to them that they could use your LocalToParent() function and avoid all the issues that dealing with quaternions raises in RAD

If you got issues with quaternions, take it up with the quaternions.