Re: Identifying just the one triangle that the user clicked on?

"Flark" <flarkino@[EMAIL PROTECTED]
> wrote in message 
news:20677af8-8703-4e79-a484-d9cbcb9733e9@[EMAIL PROTECTED]
> Hi,
>
> I'm drawing tens of 1000s of triangles and the user is going to
> click on the screen. I want to identify just the one that the
> user has clicked on. I figure select mode would be overkill
> since I'd have to establish tens of 1000s of names, one per
> triangle. Can anyone tell me of an efficient way to do this?
>
> Thanks.

The much-maligned OpenGL selection model also works fine for 10s of 
thousands of triangles.
Use the address of (or index of) some structure that identifies a triangle

as the opengl name.
Ray-triangle intersection is usually "preferred" by the experts here, but
it 
presupposes a couple of things about your app and data structures that
might 
not be true for you; if you can use it efficiently and cheaply, great. 
Otherwise, selection will work just fine. You can test the performance
very 
simply with a very trivial change in your app (worry about names later...)

jbw