You can use bezier splines (https://ibiblio.org/e-notes/Splines/bezier.html https://ibiblio.org/e-notes/Splines/bezier.html). These just use linear interpolatio

You can use bezier splines (https://ibiblio.org/e-notes/Splines/bezier.html https://ibiblio.org/e-notes/Splines/bezier.html). These just use linear interpolation, multiple times. In the case of quaternions replace the linear interpolations with quaternion slerps and you get quadratic bezier splines over orientations.