Hello ! I was looking at the script for morphing among structures that can be found here http://www.cgl.ucsf.edu/chimera/data/movie-howto-mar2012/movie_examples.html (coordset #1 1,161).  I've tried to use the surfacecat command in the script in order to obtain a morph through volumes since my idea was to create the movie and then export all the surface perframe in order to use them in another 3d software. I've seen that surfcat can actually create volumes for all the surfaces included in the 1r7w but morph start does not seems to work among the surface created. I've seen also that it could be a solution to create density maps from the surface and them morph them using volume viewer but it seem quite an awkard solution (at least for me that I'm no expert :)  I've tried to find the limitation of morph command but it does not report anything regarding surfaces. Any help is very appreciated. Sorry for the cross-posting