By the way here is the clearQuat method:
/**
* Clears all quaternions values
*/
private function clearQuat(q:Quaternion):void
{
q.w = 1;
q.x = 0;
q.y = 0;
q.z = 0;
}
On Apr 30, 12:09 pm, vangojames <[email protected]> wrote:
> Thanks for the quick response Michael. Here is my update method:
>
> /**
> * Handles renders
> */
> private function update(dt:Number):void
> {
> // recalculate the movement (this just takes inputs and populates)
> // the _tempRot Vector with dt * _angularSpeed
> updateMovementRotation(dt);
>
> // reset quaternions
> clearQuat(_tempRotQuat);
> clearQuat(_tempYawQuat);
> clearQuat(_tempPitchQuat);
> clearQuat(_tempRollQuat);
>
> // recalculate temp quaternions
> _tempPitchQuat.fromAxisAngle(Vector3D.X_AXIS, _tempRot.x);
> _tempYawQuat.fromAxisAngle(Vector3D.Y_AXIS, _tempRot.y);
> _tempRollQuat.fromAxisAngle(Vector3D.Z_AXIS, _tempRot.z);
>
> // apply quaternion rotations
> _tempRotQuat.multiply(_tempRotQuat, _tempPitchQuat);
> _tempRotQuat.multiply(_tempRotQuat, _tempYawQuat);
> _tempRotQuat.multiply(_tempRotQuat, _tempRollQuat);
>
> // apply to current rotation
> _camRot.multiply(_camRot, _tempRotQuat);
>
> // clear cam mat and update with the new rotation
> _target = _camRot.rotatePoint(Vector3D.Z_AXIS);
> _up =_camRot.rotatePoint(Vector3D.Y_AXIS);
>
> // apply look at to new target and up
> lookAt(_target, _up);
>
> }
>
> I'm sure I'm doing lots wrong, I haven't looked at Quaternions since
> University and I can't remember how they work!! I just know they will
> get rid of the dreaded Gimbal Lock,
>
> Thanks,
>
> James
>
> On Apr 30, 12:00 pm, Michael Iv <[email protected]> wrote:
>
>
>
>
>
>
>
> > If you can post the full code of your quaternion operation may be I can
> > help then .
>
> > Sent from my iPhone
>
> > On Apr 30, 2011, at 1:52 PM, vangojames <[email protected]> wrote:
>
> > > Hi guys,
>
> > > Please help me. I'm really stuck at trying to implement a Quaternion
> > > based free camera. My current approach is this:
>
> > > ON EACH UPDATE::
>
> > > - Get yaw pitch and roll increase
> > > - Create quaternions for yaw, pitch and roll (for example
> > > Quaternion.fromAxisAngle(Vector3D.X_AXIS, pitch))
> > > - Multiply together in order pitch * yaw * roll to get new temp
> > > quaternion
> > > - Multiply cameraRotation quaternion by this new temp quaternion
> > > - Calculate target by doing
> > > cameraRotation.rotatePoint(Vector3D.Z_AXIS);
> > > - Calculate up by doing cameraRotation.rotatePoint(Vector3D.Y_AXIS);
> > > - lookAt(trget, up)
>
> > > Needless to say this doesn't work. I just get the tiniest amount of
> > > movement and it isn't what is expected at all. Would someone be able
> > > to explain the correct approach?
>
> > > Thanks!!
>
> > > James
