Motion Signal Processing
------------------------
This is the paper that describes using signal processing techniques   
to process motion data (an idea that was summarized in the chapter   
about editing motion).  
  

This is an interesting paper. It describes several techniques in signal   
processing, and how to apply them for motion data. These techniques include...  
  

1. Multiresolution Filtering: The most interesting of all. This decomposes   
the signal into different parts based on frequencies. Each part is applied   
to a filter seperately, and then the signal is combined back. So, we can   
have "Audio Equalizer" like controls that specifies the strength of the   
filter on each frequency alone. We can get interesting effects playing   
around with these controls.  
2. Multitarget interpolation: This is basically motion blending.   
But, combined with multiresolution filtering, we can get some   
interesting effects. This is achieved by blending the motions   
from each frequency band separately, and then combining the results!  
3. Time warping: The basic idea was introduced in the chapter about   
motion editing. Here they describe a dynamic programming technique   
that can be used to warp one motion so that it synchronizes with another motion.   
4. Motion waveshaping: this is an easy method that is basically   
just a table that maps old values in the signal to new values   
in the output. We can use it to put constraints on angles (for example,   
we can prevent the shoulder from making more rotations than 90 degrees)  
5. Motion Displacement mapping: This was already explained in the chapter   
in the book about motion editing. Nothing new here!