Modal Warping

Modal-Warping graphical demo

This work was concerned in RT simulation of elastic objects. Specifically, it is a prototype test of the work of Ko & Choi titled 'Modal Warping' (http://cg.kw.ac.kr/modal_warping/), which synthesises former works under the name of 'stiffness warping' (http://www.cs.unc.edu/~mcmillan/papers/SSCA02_muller.pdf) and the classical approach known in CG circles as 'modal analysis' (e.g., http://www.cs.berkeley.edu/b-cam/Papers/Hauser-2003-IDU/index.html) .

This prototype mainly illustrates some graphics and optimization techniques.
The main function is ModalWarpingCheckModes, which takes as argument a valid VOL-file name. VOL is the output format of the freeware NETGEN - which is a rough and simple textual encoding of tetrahedral mesh info. Several VOL models are included (from small to large): 'y', 'sphere', 'stomach' and 'tissue_cut2'.

The routine performs a certain generalized eigen-decomposition (which can take several minutes for the larger models, depending on your system), and saves the results to a mat-file in the current folder. Future calls to the function would look for the appropriate mat-file, and compute the eigendecomposition only if it isn't found - so from 2nd launch on the init would be much, much faster.

The generated mat files range in size from 80K (for 'y') to 40M (for 'tissue_cut2') - that's why i didn't include them in the archive - so allow for sufficient disk space.

example:

ModalWarpingCheckModes('y')
ModalWarpingCheckModes('sphere')
ModalWarpingCheckModes('stomach')
ModalWarpingCheckModes('tissue_cut2')

enjoy!

Ofek