Re: How to obtain the scree
Angus Dorbie (dorbie++at++multipass.asd.sgi.com)
Sun, 20 Jul 1997 22:51:56 -0700
On Jul 20, 4:40pm, Jerry Edsall wrote:
> Subject: Re: How to obtain the scree
> RE>>How to obtain the screen posi
> On Jul 19, 6:07pm, Ren-Jye Yu wrote:
> > Subject: How to obtain the screen position of a point in the environment ?
> > Hello,
> >
> > Is there a command that allows me to obtain the x,y screen pixel
> > position of a point in the viewing scene? In other words, how can I obtain
> the
> > projection matrix in Performer?
>
> >>There's always the pfVec3::xformVec
> >>
> >>If you use the modelviewing matrix it should give you coordinates -1 to +1
> >>which you can then scale to match your viewport.
> >>
> >>
> >>Cheers,Angus.
>
> But woudn't that have to be done in the draw callback? Isn't there a way to
do
> it in the application?
>
No, afterall you set your matrices in the application, you have
enough info to do the math.
You could do it in the draw. btw I'll repeat, I should also have
mentioned the projection matrix too.
Cheers,Angus.
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on Mon Aug 10 1998 - 17:55:38 PDT