VMD-L Mailing List

From: Norman Geist (norman.geist_at_uni-greifswald.de)
Date: Fri Feb 13 2015 - 09:25:36 CST

John,

I've tested doing:

1. open VMD
2. disable axis
3. enable ruler
4. set env(VMDOPTIXBUILDER) "MedianBvh"
5. render using TachyonOptix

This worked, although the ruler looked weirdly bended.
In the same VMD session a switching to "Trbvh" again, brought
the error back.

Hope that helps

Norman Geist

> -----Original Message-----
> From: John Stone [mailto:johns_at_ks.uiuc.edu]
> Sent: Friday, February 13, 2015 3:55 PM
> To: Norman Geist
> Cc: VMD Mailing List
> Subject: Re: vmd-l: Handful of rendering issues
>
> Norman,
> Please try this experiment for me:
> Set the environment variable VMDOPTIXBUILDER to "MedianBvh"
> and try rendering the same scenes you have been rendering that
> caused trouble. I'm suspicious that you have found some kind
> of bug in the "Trbvh" builder in OptiX 3.6.x, because there were
> a string of buglets that got fixed in "Trbvh" and I wonder if
> there were still a few more hanging out there. Switching to
> "MedianBvh" changes nothing that VMD does, but it changes which
> acceleration structure builder OptiX uses internally, and the
> "MedianBvh", while not as fast as "Trbvh" has been reliable for
> me in VMD for a long time now, and has performed correctly in all
> of the cases where "Trbvh" has broken.
>
> Make sure you get the capitalization of the builder string correct
> or OptiX will ignore it.
>
> Cheers,
> John Stone
> vmd_at_ks.uiuc.edu
>
>
> On Fri, Feb 13, 2015 at 08:42:15AM +0100, Norman Geist wrote:
> > John,
> >
> > the GPU has 2GB of VRAM. Nothing else, except KDE4 is running.
> > Before starting VMD, nvidia-smi shows 158MB out of 2047MB used.
> > After starting VMD, nvidia-smi shows 282MB out of 2047MB used.
> >
> > So rendering only the ruler then breaks the renderer. My 1st guess
> was that
> > the "empty" ruler molecule
> > having only drawn objects, doesn't have the expected molecule memory
> > structure set up which TachyonOptix tries to
> > transfer to the GPU. Therefore I tried the following, which will lead
> to the
> > same error:
> >
> > 1. open fresh vmd
> > 2. disable axis
> > 3. mol new
> > 4. graphics 0 sphere {1 1 1}
> > 5. render using tachyonoptix
> >
> > Let me know if I can help to dig it down further.
> >
> > Norman Geist.
> >
> > > -----Original Message-----
> > > From: John Stone [mailto:johns_at_ks.uiuc.edu]
> > > Sent: Thursday, February 12, 2015 4:16 PM
> > > To: Norman Geist
> > > Cc: VMD Mailing List
> > > Subject: Re: vmd-l: Handful of rendering issues
> > >
> > > Norman,
> > > How much video memory does your GPU have?
> > > What else are you running on the machine at the time that this
> > > error occurs? (for example, is Google Chrome running? Other
> > > instances of VMD? Anything else that uses the GPU at all?)
> > >
> > > Cheers,
> > > John
> > >
> > > On Thu, Feb 12, 2015 at 09:44:34AM +0100, Norman Geist wrote:
> > > > Hey John,
> > > >
> > > > the exact error message is:
> > > >
> > > > ERROR) OptiXRenderer) ERROR: Unknown error (Details: Function
> > > "RTresult
> > > > _rtContextLaunch2D(RTcontext, unsigned int, RTsize, RTsize)"
> caught
> > > > exception: (bvhtools error)An unexpected memory allocation error
> > > occurred in
> > > > TrivialThrustAllocator, [21823538], [15270173])
> (OptiXRenderer.C:1188
> > > >
> > > > GPU is a Geforce GTX660 (propritary NVidia driver version:
> 343.22)
> > > >
> > > > This error occurs for me doing the following steps:
> > > >
> > > > 1. open a fresh vmd
> > > > 2. disable axis
> > > > 3. enable ruler in scale mode
> > > > 4. render using TachyonOptix (interactive or not)
> > > >
> > > > Norman Geist.
> > > >
> > > > > -----Original Message-----
> > > > > From: John Stone [mailto:johns_at_ks.uiuc.edu]
> > > > > Sent: Wednesday, February 11, 2015 5:21 PM
> > > > > To: Norman Geist
> > > > > Cc: 'Tristan Croll'; VMD Mailing List
> > > > > Subject: Re: vmd-l: Handful of rendering issues
> > > > >
> > > > > Norman,
> > > > >
> > > > > On Wed, Feb 11, 2015 at 04:32:35PM +0100, Norman Geist wrote:
> > > > > > 1. Using the "ruler" in "scale" mode, when nothing
> else
> > > > > (including
> > > > > > axis) is visible, TachyonOptix will crash.
> > > > >
> > > > > I don't get a crash when I do this on my system here, but I
> will
> > > > > say that the rendering of the scale bar is pretty wacky due to
> > > > > weaknesses in the scheme I used for setting cylinder radii for
> > > OptiX
> > > > > when drawing lines in VMD 1.9.2, something that still needs
> more
> > > work.
> > > > > Can you post the error message that VMD prints?
> > > > > Without the error it's hard to say what's going on there for
> you.
> > > > >
> > > > > > 2. The general fact TachyonOptix will no more work
> > > without
> > > > > > restarting VMD, if it has crashed once.
> > > > >
> > > > > It depends. If the OptiX runtime runs out of GPU memory or
> other
> > > > > scenarios that it can't bail out of, it will terminate
> rendering
> > > and
> > > > > usually destroy the OptiX context on its way down. In some of
> > > these
> > > > > cases,
> > > > > the state of the CUDA context also gets destroyed, and VMD is
> not
> > > able
> > > > > to
> > > > > recover it. There are also a lot of cases where VMD does
> recover
> > > from
> > > > > less serious issues, but unfortunately, I'd say that running
> the
> > > GPU
> > > > > out
> > > > > of memory is one of the more common problems, particularly on a
> > > machine
> > > > > where other graphical apps are competing for resources (e.g.
> Google
> > > > > Chrome,
> > > > > a surprisingly resource hungry application, in terms of GPU
> > > memory...)
> > > > >
> > > > > Cheers,
> > > > > John
> > > > >
> > > > >
> > > > > > Norman Geist.
> > > > > >
> > > > > >
> > > > > >
> > > > > > From: owner-vmd-l_at_ks.uiuc.edu [mailto:owner-vmd-
> l_at_ks.uiuc.edu]
> > > On
> > > > > Behalf
> > > > > > Of Tristan Croll
> > > > > > Sent: Wednesday, February 11, 2015 12:15 PM
> > > > > > To: vmd-l_at_ks.uiuc.edu
> > > > > > Subject: vmd-l: Handful of rendering issues
> > > > > >
> > > > > >
> > > > > >
> > > > > > Hi there,
> > > > > >
> > > > > >
> > > > > >
> > > > > > I have a few minor rendering-related issues/suggestions in
> VMD
> > > > > 1.9.2:
> > > > > >
> > > > > >
> > > > > >
> > > > > > - If I have an isosurface visualised in the default point
> > > > > representation
> > > > > > and switch to GLSL rendermode, every point becomes a VERY
> > > large
> > > > > sphere and
> > > > > > the system slows to a crawl.
> > > > > >
> > > > > >
> > > > > >
> > > > > > - When a wireframe is rendered in Tachyon the lines are of
> > > course
> > > > > replaced
> > > > > > by thin cylinders. This works out nicely in the CPU-only
> > > Tachyon
> > > > > > (particularly if I use a transparent material, yielding a
> > > nicely
> > > > > > unobtrusive mesh), but the cylinder diameter is much
> larger in
> > > > > > Tachyon-OptiX. Is it possible to shrink this, or is this
> one
> > > of
> > > > > the
> > > > > > trade-offs that allows the renderer to be so blazingly
> fast?
> > > > > >
> > > > > >
> > > > > >
> > > > > > - When using the interactive renderer, closing the
> rendering
> > > > > window with
> > > > > > the mouse rather than pressing Esc or q crashes VMD.
> > > > > >
> > > > > >
> > > > > >
> > > > > > - I think it would be awesome if the interactive renderer
> had
> > > an
> > > > > option to
> > > > > > render the scene at some multiple of the screen
> resolution,
> > > for
> > > > > when
> > > > > > poster-quality images are needed.
> > > > > >
> > > > > >
> > > > > >
> > > > > > Cheers,
> > > > > >
> > > > > >
> > > > > >
> > > > > > Tristan
> > > > > >
> > > > > >
> > > > >
> > > > > --
> > > > > NIH Center for Macromolecular Modeling and Bioinformatics
> > > > > Beckman Institute for Advanced Science and Technology
> > > > > University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
> > > > > http://www.ks.uiuc.edu/~johns/ Phone: 217-244-3349
> > > > > http://www.ks.uiuc.edu/Research/vmd/
> > >
> > > --
> > > NIH Center for Macromolecular Modeling and Bioinformatics
> > > Beckman Institute for Advanced Science and Technology
> > > University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
> > > http://www.ks.uiuc.edu/~johns/ Phone: 217-244-3349
> > > http://www.ks.uiuc.edu/Research/vmd/
>
> --
> NIH Center for Macromolecular Modeling and Bioinformatics
> Beckman Institute for Advanced Science and Technology
> University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
> http://www.ks.uiuc.edu/~johns/ Phone: 217-244-3349
> http://www.ks.uiuc.edu/Research/vmd/