From: Goedde, Chris (
Date: Tue Oct 06 2020 - 15:32:23 CDT

Thanks, that worked great.


> On Oct 6, 2020, at 10:46 AM, John Stone <> wrote:
> Hi,
> You can place objects at a fixed screen location by
> purposefully setting the view transformation matrices
> for the molecule(s) of interest, and toggling those
> molecules (F)ixed in the GUI (or by script commands).
> If you're not a computer graphics expert, you may find
> calculation of the view transformation matrices to be
> a somewhat daunting task, but these are concepts
> that are well documented in basic computer graphics
> texts, so if you want perfect control over on-screen
> placement, that's really the only way to get it.
> In general VMD computes the view transforms by computing
> an axis-aligned bounding box for the top molecule's contents,
> and applying a scaling operation such that it should fit
> within the VMD view frustum with typical camera/display
> screen height and distance parameters. This auto-scaling
> is the main reason that you get varying outcomes for a given
> set of coordinates for things like text, even when they are
> in their own independent molecule. By setting the transformation
> matrices yourself and locking them (making the molecule "fixed")
> you prevent the autoscaling behavior from impacting the view.
> Best regards,
> John Stone
> On Mon, Oct 05, 2020 at 07:39:02PM +0000, Goedde, Chris wrote:
>> Hi all,
>> Is there a way to place text (or other graphics objects) at a fixed (x, y) location on the display, independent of atomic coordinates or the rotation or scaling state of the view?
>> Thanks,
>> Chris
> --
> NIH Center for Macromolecular Modeling and Bioinformatics
> Beckman Institute for Advanced Science and Technology
> University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
> Phone: 217-244-3349