[vtkusers] Rendering into pre-existing OpenGL-window without any vtkRenderWi ndow-Instance

[Lisa Avila]

Hi Marian,


>Next thing is, that i'm not only getting the OpenGL-window from another
>program, the program is responsible for cameras/lights as well. That's the
>reason for my intention to have a Render-thingabob, which really doesn't
>care about anything else than rendering geometry _but_ is able to work
>together with Interactors and widgets.


No - VTK does not have a way to do this - you need to duplicate your lights 
/ camera in VTK. The reason for this is that some mappers / filters use 
information in these object in order to do their thing. For example, if you 
use a volume ray cast mapper (structured or unstructured) it needs to know 
the light / camera information in order to generate an image in software 
which it then displays on the screen. Or if you use the depth sorting 
filter for polygons in order to produce good transparent effects, the 
camera information is required to perform the correct sorting. Providing a 
way to not specify the camera / light information in VTK would mean a big 
headache in figuring out which mappers  / filters you couldn't use that way.

Lisa