Get Deltas

/**
 * Node that computes vertex deltas between two meshes.
 * 
 * Calculates the difference between a base mesh and a morphed mesh,
 * outputting deltas that can be applied elsewhere.
 * 
 * Usage:
 * 1. Connect base mesh and morphed mesh (must have matching topology)
 * 2. Output deltas pin contains the computed differences
 */