ba_interp3 is a fast interpolation routine for 3D volumes. It can be used as a drop in replacement for matlabs interp3 function. It supports nearest neighbour, tri-linear, and tri-cubic interpolation.

Restrictions: The only restriction is, that the data has to be on a regularly spaced grid (i.e. coming from meshgrid.

Enhancements: The first advantage of ba_interp3 is that it is a lot faster.
ba_interp3 is up to 10 times faster than matlabs interp3 in realistic scenarios

Additionally, it can interpolate layered data. If you interpolate a matrix of size MxNxO x L1xL2x...xLk then each of the L1*L2*...*Lk layers is interpolated simultaneously. Think of this as in RGB images, where there would be a single additional dimension of size three.
An volume of 3x3 Matrices (i.e. the volume derivative) would have two additional dimensions of size three.