From: Vincent Ustach (
Date: Wed Jan 17 2018 - 10:02:22 CST

Dear VMD List,

I have a field of 1s and 0s with isosurface representation in VMD (VMD for
LINUXAMD64, version 1.9.1 (February 1, 2012). I noticed that with Draw
Points, the Isovalue does not affect the isosurface. With Draw Wireframe
and Draw Solid Surface, an Isovalue of 1.0 gives the same surface as Draw
Points, but decreasing Isovalue towards 0.0 causes the isosurfaces to

Since the grid has values of 0 and 1, I guess there is some interpolation
scheme that "finds" where the volume is equal to the Isovalue. Is that
true? Can someone please explain how it works?

Best Regards,

Vinnie Ustach