VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Fri Nov 10 2017 - 22:16:35 CST

Dallas,
  Clearly the first image you posted was odd.
One thought I have that this might be caused by simultaneous use of both
Depth Cueing (Fog) and a background gradient. When you use Depth Cueing
or Fog, or similar shading techniques that try to emulate atmospheric
effects like light extinction or scattering, you may get a saturated
color long before you reach the background gradient, which is treated as
being at an infinite distance. I assume that this might be what happened
to you with the first try you did. You might try rendering with depth cueing
enabled/disabled and compare your outcome, I bet that was it.

If it wasn't caused by depth cueing, then I don't have any other suggestion
presently. Let me know if it recurs.

Best,
  John Stone
  vmd_at_ks.uiuc.edu

On Wed, Nov 08, 2017 at 10:16:12AM +1100, Dallas Warren wrote:
> It appears to be working correctly now, not sure what I have done
> differently here.
>
> https://twitter.com/dr_dbw/status/928037977124507648
>
> The background is now the correct gradient colouring.
> Catch ya,
>
> Dr. Dallas Warren
> Drug Delivery, Disposition and Dynamics
> Monash Institute of Pharmaceutical Sciences, Monash University
> 381 Royal Parade, Parkville VIC 3052
> dallas.warren_at_monash.edu
> ---------------------------------
> When the only tool you own is a hammer, every problem begins to resemble a nail.
>
>
> On 31 October 2017 at 12:08, Dallas Warren <dallas.warren_at_monash.edu> wrote:
> > John,
> >
> > Just wanted to check if this is the expected behaviour of renderer.
> >
> > Render: TachyonLOptiXInternal
> > Display background: gradient, top black, bottom blue2
> >
> > The background of these rendered frames is solid blue (half way
> > between the black and blue2 of the gradient background), from top to
> > bottom, no gradient.
> >
> > When there is BlownGlass material present, then the internal region
> > within the glass towards the top is black, towards the bottom is
> > blue2, and center is the same as the frame background.
> >
> > So are seeing the display background through the glass and being
> > rendered as such, but the background is being rendered as a middle
> > colour of the display background. Image to show this can be found at
> > https://twitter.com/dr_dbw/status/925167062514679808
> >
> > Catch ya,
> >
> > Dr. Dallas Warren
> > Drug Delivery, Disposition and Dynamics
> > Monash Institute of Pharmaceutical Sciences, Monash University
> > 381 Royal Parade, Parkville VIC 3052
> > dallas.warren_at_monash.edu
> > ---------------------------------
> > When the only tool you own is a hammer, every problem begins to resemble a nail.
> > 

-- 
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/