[Chimera-users] Normal recalculation

[Elaine Meng]

Dear Damien,
In Chimera version 1.4 (daily builds) there is a quality option in the  
Lighting tool (under Tools... Viewing Controls).  Depending on your  
machine, you may be able to set the "quality" to "glossy" -- this will  
make surfaces of all kinds look much smoother without increasing the  
number of triangles.  My knowledge of how it works is a little fuzzy,  
but I thought it somehow uses different normals all over the surface  
instead of just one normal for each triangle.  The "glossy" option  
also turns on angle-dependent transparency.
<http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/sideview.html#lighting.

Glossy lighting was discussed in a little more detail in these recent  
messages:
<http://www.cgl.ucsf.edu/pipermail/chimera-users/2009-June/004031.html>
<http://www.cgl.ucsf.edu/pipermail/chimera-users/2009-June/004032.html>

If the main reason for your question is wanting to make the surfaces  
look better, glossy lighting should suffice... as long as you can use  
a computer on which it is available.  I don't know anything about  
getting the normal information out of Chimera (and the person who  
implemented glossy lighting is on vacation right now).
I hope this helps,
Elaine
-----
Elaine C. Meng, Ph.D.
UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab
Department of Pharmaceutical Chemistry
University of California, San Francisco
                      http://www.cgl.ucsf.edu/home/meng/index.html


On Jul 2, 2009, at 3:20 AM, Damien Larivière wrote:

> Dear Chimera team,
>
> I have open in Chimera a VRML file containing multiple copies of the  
> FtsZ protein.
>
> The VRML file does not contain the smooth groups so that, at  
> display, triangles appear at the surface of the proteins as shown in  
> the attached image.
>
> I would like to get the surface smooth but not by increasing the  
> number of triangles.
>
> Is there a way in Chimera to recalculate the normals as it can be  
> done in 3DSMax for instance?
>
> My best regards,
>
> Damien