From: Rune Thomas Kidmose (
Date: Sun Oct 01 2017 - 14:20:13 CDT

Hi all,

Lately I have been playing around with the Tachyon engine in VMD, and must say I am very impressed by what it can do and how easy it does it, truly!!

However, if I want to render a close-up of a density map around e.g. a couple of residues, I have run into some hurdles .

Lets say I load in a mrc density file and the corresponding PDB file.

I set up the view where I zoom-in on a couple of residues of interest. I display the mrc density as a isosurface and find the optimal isovalue and display the residues as licorice etc.

No matter which of the two engines (OptiX or OSPRay) I then use, I get very thick density mesh around the residues so I can almost not see the residues at all.

>From the GUI, I was not able to change the isosurface mesh size below that of 1 (graphics --> representation --> Isosurface --> Size). However, I finally figured out that I could change the value to sub 1 using the TK console--_000_15068856137292516mbgaudk_--