On Sat, Jul 16, 2011 at 08:16:44PM -0400, Anne Archibald wrote: > The next interesting question is, how well does scipy.interpolate deal > with them? For really good rotational paths I seem to recall you want > specialized splines, but simply interpolating in the quaternion domain > is not a bad quick and dirty approach.
Hi Anne, Actually that's next on my list. The most commonly used quaternion interpolation algorithm is Ken Shoemake's SLERP. There is an improved one called SQUAD which is C^1-continuous, i.e defines continuous angular velocities as well as just rotations. For the inertial sensing simulator I mentioned we needed C^2 continuitiy, so we implemented the quaternion B-spline algorithm from: M-J Kim, M-S Kim and S Y Shin, "A General Construction Scheme for Unit Quaternion Curves with Simple High Order Derivatives, in "Proceedings of the 22nd Annual Conference on Computer Graphics and Interactive Techniques (SIG-GRAPH’95)", pp. 369-376, ACM, 1995. At the moment this uses our Cython-based quaternion library, but my plan once the quaternion dtype is nailed down would be to rewrite these interpolators to use the dtype, and submit the result to scipy.interpolate. Martin _______________________________________________ NumPy-Discussion mailing list [email protected] http://mail.scipy.org/mailman/listinfo/numpy-discussion
