Re: Moving and Rotating Camera.

Hi Ajit,
The two different ways you are visualizing things here might look
different intutively but give out the same final result.  Everything
eventually needs to be transformed to the view space.

Since you have the position and the direction vector (and possibly an
up vector, if your car is shaking a lot ;) or use (0, 1, 0) if not),
you can create a model view matrix using these vectors.

Essentially, you need three vectors: direction, right and up. You
already have the direction vector, cross (direction, (0, 1, 0)) will
give you the right vector. cross (right, direction) will then give you
the up vector. let these vectors we n (direction), u (right) and v
(up). Lay your model view matrix as:

u.x u.y u.z -pos.x
v.x v.y v.z -pos.y
n.x n.y n.z -pos.z
0.0 0.0 0.0 1.0

and load it in your GL_MODEVIEW matrix.

If this is too much detail, you can use gluLookAt to get similar
results. (I am passing complete vectors here, you will have to pass
individual components)
gluLookAt (pos, pos + dir, (0, 1, 0));

Just making it look a unit away into the given direction.

Hope this helps,
Uday

On 3/11/06, Ajit Singh <[email protected]> wrote:
> Hello,
>
> I'm working on a Racing Game and I want to move and rotate the camera along
> with car in the Game. I have to do this i.e, to Move and Rotate the camera
> using Lookat, I mean using Position Vector and Direction Vector.
>
> There is an another alternative to move the world in the opposite direction,
> but I want to go with the first, that is the camera movement.
>
> I'm not able to do that.
>
> Any Help Appreciated.
>
>
> Regards & Thanks
> Ajit Singh
> Trainee Software Enggineer.
> Lambent Technologies Pvt. Ltd.
>
>
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Author: Uday Karan
  INET: [email protected]

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