[Chimera-users] Shadows

dbhel001 at udcf.gla.ac.uk dbhel001 at udcf.gla.ac.uk
Fri Feb 12 12:03:13 PST 2010

Hi Elaine,

Sorry for the confusion, yes I did have 'show shadows' enabled and in version
1.4 this gave really nice shadows for 3d reconstructions as well as molecular
surfaces. So much so that I had stopped using POV-RAY altogether 
because of the
time penalty when ray-tracing a long movie.
One difference I noticed between 1.4 and 1.4.1 is that when rendering
supersampled images in 1.4 there was no flashing of each tile in the viewer,
rather it just said 'rendering high resolution image' at the bottom of the
window. This may or may not relate to the manner in which the image is
calculated (sorry if that seems a bit of a random observation!)


Quoting Elaine Meng <meng at cgl.ucsf.edu>:

> Hi David,
> I'm a bit confused about what you mean.  Images saved directly from  
> Chimera (non-raytraced) do not have shadows per se, but they do have  
> "shading."  Although there is an "show shadows" setting in the 
> Effects  tool, it is turned off by default, and those shadows are 
> always blocky  as far as I know, and not intended for saved images, 
> only as  interactive previews for raytracing.  You probably aren't 
> using that  "show shadows" setting.  Conversely, with raytracing 
> there is no such  thing as supersampling.
> If you were showing atoms/ribbons, I'd suggest increasing 
> "subdivision  quality" (also in Effects) to increase the smoothness 
> of the objects  and thus the shading in Chimera.  However, this does 
> not affect  isosurfaces.  There are separate smoothing controls in 
> Volume Viewer  for such surfaces, see this recent post:
> <http://www.cgl.ucsf.edu/pipermail/chimera-users/2010-February/004764.html >
> Check that you are using the full resolution of your data and not a  
> subsampling (coarser grid).
> My only other idea is that maybe you were using raytracing before.
> If none of these comments help, please use "Help... Report a Bug" in  
> the Chimera menu and include a complete description of your  
> situation.  This also allows attaching a file and including your 
> email  address for a response.
> Best,
> Elaine
> -----
> Elaine C. Meng, Ph.D.
> UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab
> Department of Pharmaceutical Chemistry
> University of California, San Francisco
> On Feb 12, 2010, at 8:06 AM, David Bhella wrote:
>> Hi,
>> I just updated my Chimera installation to 1.4.1 (Mac OSX aqua), and  
>> I noticed that for some reason shadows are not so nicely rendered in 
>>  standard 3x3 super-sampled output.  They look very blocky, much as  
>> they always have done in the viewer. In version 1.4 I always got  
>> very nice shadows when I saved an image. I am trying to save images  
>> of an isosurface view of a 3D reconstruction. Is there a setting I  
>> need to adjust to get high quality shadows back again?
>> Many thanks,
>> Dave

This message was sent using IMP, the Internet Messaging Program.

More information about the Chimera-users mailing list