Hi Tatiana, If you want the (x,y,z) coordinates for the a connected piece of a contour surface you could use the "Color and Measure Surface Pieces" extension on the Chimera experimental features page (2nd from the bottom): http://www.cgl.ucsf.edu/chimera/experimental/experimental.html http://www.cgl.ucsf.edu/chimera/experimental/pickblobs/pickblobs.html That extension allows you to colors and reports the volume and area of individual blobs chosen with the mouse. You could add a small bit of Python code to that extension to print the surface coordinates. For example, you could add for xyz in varray: print '%12.5f %12.5f %12.5f' % xyz at the end of the color_and_measure() routine in PickBlobs/gui.py to print the blob surface vertex coordinates. The printed results would go to the Chimera Reply Log dialog when you click on a blob. Those coordinates could be saved to a file (cut and paste). The triangles that make up the surface blob are described by tarray (N by 3) where each triple of integers defines the indices of the triangle vertices in varray. Tom