VMD-L Mailing List

From: Laurence F. Wood (LaurenceWood_at_SunyataSystems.Com)
Date: Mon May 13 2002 - 13:09:19 CDT

Hey John,

Second that! We use the alpha channel for transparency and it looks
much better and provides more flexibility (allowing the user to select
how transparent something is wins big time). I would wager that most
users have opengl acceleration of some sort (most laptops come with
opengl hardware these days.)

Larry

-----Original Message-----
From: owner-vmd-l_at_ks.uiuc.edu [mailto:owner-vmd-l_at_ks.uiuc.edu] On Behalf
Of Todd J. Furlong
Sent: Monday, May 13, 2002 12:21 PM
To: John Stone
Cc: tripp_at_fis.unam.mx; vmd-l_at_ks.uiuc.edu; vmd_at_ks.uiuc.edu
Subject: Re: transparency

I see in the code that transparency is implemented using the "screen
door" method with glPolygonStipple rather than using the alpha channel.
     I assume this was done because it is faster, but is there another
reason? Maybe having the option for either method would be a desirable
feature of VMD 1.8?

-Todd

John Stone wrote:
> Hi,
> To use the draw or graphics commands with your own materials,
> you first need to define your material with the material editor
> if you're not using one of the two default materials "Opaque" and
> "Transparent". Once the materials are defined, you can use a command
> like this to draw things with that material property (case sensitive):
> draw material Transparent
>
> Or for your own material name:
> draw material MyNeatoMaterial
>
> If you need to have graphics objects with different materials, then
you'll
> need to use the "graphics" commands with ID tags to differentiate
which
> one you're working on, etc. This is documented in the User's guide
> here:
> http://www.ks.uiuc.edu/Research/vmd/vmd-1.7.1/ug/node167.html
>
> The graphics/drawing interface is changing slightly for VMD 1.8, but
> if you do your work on VMD 1.7.1 it should be easy to update later.
>
> Enjoy,
> John Stone
> vmd_at_ks.uiuc.edu
>
> On Fri, May 10, 2002 at 11:46:01AM -0500, tripp_at_fis.unam.mx wrote:
>
>>Hi L,
>>
>>this is a simple question, but nothing seems to work;
>>how can I draw a transparent cylinder?
>>
>>I'm using VMD 1.7.1 in redhat
>>
>>thx
>
> 

-- 
Todd J. Furlong
Visualization Engineer
Delta Search Labs
400 Technology Square
Cambridge, MA 02139
617.551.4607
617.551.4651