[vtkusers] Repositioning Image within Render Window

[David Gobbi]

On Wed, Oct 20, 2010 at 6:04 PM, Alexis Cheng <acheng_1221 at hotmail.com> wrote:
> Hi David,
>
> That was the example I used to set the background to an image. Is it
> possible to have multiple cameras focused on different objects?

The only way to have multiple, simultaneous cameras is to have
multiple renderers sharing a render window (which means they share the
color buffer and depth buffer of the window).  I strongly advise
against doing this, though, because it can be tricky to have two
renderers share a depth buffer properly.

Usually I find that it is best to ground everthing within a common
coordinate system, and I always use the world coordinate system as my
"ground".  Then I have most actors positioned correctly with respect
to this "ground", and for other actors I have them follow the camera
i.e. every time the camera moves, I reposition those actors within the
world coordinate system to keep them stationary with respect to the
camera.

  David