[cad-linux] Re: database access methods
- From: Roland Krause <rokrau@xxxxxxxxx>
- To: cad-linux@xxxxxxxxxxxxx
- Date: Fri, 16 May 2003 11:30:39 -0700 (PDT)
Jim,
gluLookAt() does what you have in mind. If you want to know what it's
doing look at the Mesa sources. For an explanation have a look at the
"Red Book".
Regards,
Roland
--- Jim Parker <hopeye@xxxxxxxxxx> wrote:
>
> On 2003.05.16 12:06 Roland Krause wrote:
>
> > >
> > > viewer. Does anyone know a simple routine to convert a vector to
> > > OpenGL rotation angles ? You can not use simple force resolution
> > > routines.
> >
> > Do you mean a virtual trackball that allows you to rotate the scene
> or
> > a camera? I have both, let me know what you need. They are from the
> > net, if you google for virtual trackball you will find them.
> >
> > Roland
> >
> >
>
> Not quite. An example should help. Suppose your model is centered
> on
> a global orthoginal right handed coordinate system. You are at a
> arbitrary distance far enough away to see the entire model.
>
> If you are looking down the Z-axis at the X-Y Plane. The orientation
>
> unit vector would be: (0i + 0j + 1k)
>
> Now let say you want to rotate the coordinate system so you are
> looking
> down the X-axis at the Y-Z plane.
> The new orientation vector is (1i + 0j + 0k). This requires a 90
> degree rotation about the Y axis in OpenGL.
>
> Now it is easy to write a simple if-else code block for the six major
>
> faces. What I am looking for is a general routine to handle any
> arbitrary vector. An example would be a isometric view obtained by a
>
> 30 degree rotation about the X-axis, then another 30 degree rotation
> about the Y-axis.
>
> Like I said in my previous post, you can't simply extend the force
> resolution routines.
>
> thanks for your help.
>
> cheers,
> Jim Parker
>
__________________________________
Do you Yahoo!?
The New Yahoo! Search - Faster. Easier. Bingo.
http://search.yahoo.com
Other related posts:
