From: Jason Smith (
Date: Mon Aug 23 2021 - 12:44:15 CDT

Hi Prateek,

I remember having trouble (on windows) with something similar. Transparency would cause a hang because most of my ram and vram was actually busy with another program - turning off transparency would work fine though, as did turning off the other programs like web browsers. However, I also know there have been some Mac specific problems in the past. Perhaps try to see if memory or OS is a contributing factor?


Jason Smith
Post-Doctoral Fellow
Robert N. Young Lab, Simon Fraser University
8888 University Drive, Burnaby, BC, V5A-1S6

From: <> on behalf of Vermaas, Josh <>
Sent: Monday, 23 August 2021 9:47 AM
To: Prateek Bansal;
Subject: Re: vmd-l: VMD Tachyon Render fails with new material

Does it “work” with one of the glasses? Transparent surfaces make Tachyon do *a lot* more work. Depending on your settings, it can take quite a while to render, especially with CPUs only, like it would be on a Mac.


From: <> on behalf of Prateek Bansal <>
Date: Monday, August 23, 2021 at 12:26 PM
To: "" <>
Subject: vmd-l: VMD Tachyon Render fails with new material

Hello VMD Community,

I am trying to use VMD to visualize a membrane protein. I have output from the HOLE2 program which lets me visualize the tunnel inside it. To visualize the tunnel better, I use a surf representation of the protein and make a new material with lesser opacity. When I try to render it using Tachyon/Tachyon Internal, VMD stops responding and I have to end up closing it. Rendering works when the material is one of the default ones (Opaque, for e.g.). Any insights would be appreciated.

I am using MacOS 10.15 (Catalina) and VMD 1.9.4a51.