[Chimera-users] odd glare when volume rendering

[William Jeffrey Triffo]

you are right,

I now see nothing (must not support 3D textures) and the display update 
is real slow, but the same glare persists.

here are a few screenshots (awaiting approval); they are at a few 
different orientations to show dependence. the two 'with' and 
'without2D' textures show same orientation with that option toggled 
on/off. the rendering disappears, but the glare remains.

also, if relevant, most of the volume is empty space (zeros) - the only 
data is along the diagonal of the box in a thin strip.

I had not had this problem before with similar data in previous versions 
of Chimera (thin strip in volume of mostly zeros or otherwise), 
prompting me to ask. I don't think I had tried to volume render since I 
installed this version (2416) a while back; could this be due to a 
change between versions?

thanks,

-Jeff


Thomas Goddard wrote:
> Hi Jeff,
>
>   You can send an image to chimera-users.  Messages over 40 Kbytes 
> have to await approval before posted though.
>
>   Solid rendering has no directional lighting as you can verify 
> changing the light source direction using Tools / Viewing Controls / 
> Lighting.
>
>   The default solid rendering mode uses OpenGL 2D textures stacked up 
> along the data axis (x,y, or z) most in line with your view.  You 
> probably are seeing artifacts related to that.  You can try switching 
> off "Solids using 2D textures" in the volume dialog "Solid rendering 
> options" panel.  With a high-end graphics card that will use 3-D 
> textures that don't have as many artifacts.  If your graphics card 
> does not support 3D textures you will just see an outline box with no 
> data.
>
>     Tom
>

-- 
-------------------------------------------------------------
Jeff Triffo
Auer Group, Donner Lab, Lawrence Berkeley National Laboratory
Raphael Group, Bioengineering Department, Rice University
Medical Scientist Training Program (MSTP), Baylor College of Medicine
phone (Berkeley): 510-486-7940
fax   (Berkeley): 510-486-6488   

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