Re: TGeo shadows,

From: Andrei Gheata <Andrei.Gheata_at_cern.ch>
Date: Fri, 13 Nov 2009 08:14:11 +0100


Hi John,
As you have correctly observed, GL is the right place to handle shadows, but this is not available yet. A model with light and surfaces to project shadows onto may be implemented in TGeo itself using ray tracing, but this would be much slower. I attached the expert in GL and EVE who may know more.

Best regards,
Andrei

John Idarraga wrote:
> Hello
>
> Seems like shadows are more a render-time issue. In that case the TGeo
> package does not have to deal with that at all, am I right ? Then my
> question changes to. How do I access those properties ? Apparently
> OpenGL does not support shadow rendering directly. But GLUT has
> examples on how to use the stencil buffer which seems to be an appealing
> option. It would be nice to see shadows projected on any type of
> surface. Like an sphere. Anyway, I have no clue on how to access those
> tools.
>
> I am guessing that through the EVE set of classes one should find it's
> way to the GL internals.
>
> thanks,
>
> John Idarraga
>
> On Thu, 2009-11-12 at 12:13 -0500, John Idarraga wrote:

>> Hello people,
>>
>> A question regarding the TGeo package.  Suppose you define a volume (a
>> box for example) and then, say, somehow you define a light source.  You
>> want to see the shadow of that image in a given plane in the space.  And
>> better, you want to know the area of that shadow in that particular
>> plane.  Those algorithms exist, and I wonder if they are included in the
>> TGeo package.
>>
>> bests,
>>
>> John Idarraga
>>
>>

>
>
Received on Fri Nov 13 2009 - 08:14:21 CET

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