Quaternion conversion extrinsic to intrinsic

[Sly_Raccoon]

Hi All,

I Have a system which is supplying me with quaternions, working in opengl I am setting the orientation of a model to the quaternion I am given, and it is seen that all changes in pitch are shown as changes in rotation around the opengl x-axis (1 is left), all changes in roll are shown as changes in rotation around the opengl z axis (1 is out of the screen) and all changes in yaw are shown as changes in rotation around the opengl y-axis (1 is up).

is there a way to convert this rotation around a fixed axis system to a rotation around a rotating axis system?

Regards.
Graham

 

[jvicens]

Hi Graham,

Thank you for sharing your question with the forum. It sounds like you are working with a system that supplies you with quaternions, which are a type of mathematical object used to represent rotations in 3D space. In OpenGL, these rotations are typically applied using the fixed axis system, where the x, y, and z axes are fixed and do not change. However, it is possible to convert these rotations to a rotating axis system, where the axes change with each rotation.

To do this, you will need to use some mathematical equations to convert the quaternion rotations to Euler angles, which represent the rotation around the x, y, and z axes. From there, you can apply the rotations using the rotating axis system. There are several resources online that can help you with the conversion process, such as this blog post from Unity or this paper from the University of Cambridge.

I hope this helps you with your project. Let me know if you have any further questions or need any clarification.