Hi Robert,

On Friday 01 June 2007 18:05, Robert Osfield wrote:
> On 6/1/07, Emmanuel Roche <[EMAIL PROTECTED]> wrote:
> > okay, and in this case, is it possible / tested to have multiple viewers
> > on the same OpenGL Context ?...
> You can multiple views that share the same graphics context, but
> you'll need to use a single CompositeViewer for it to ensure that the
> threads are sycronized.
> You also need to realistic, frame rate is governed by the swap buffers
> of a window, when you do swap buffers all cameras drawing to that
> window have to redrawn, you can't selectively say I just want swap
> buffers on one cameras viewport on that window.

Well, I can see an application of a frame rate limit for specific contexts.

I would like to make mpeg movies from a running simulation with an existing 
viewer with one or more windows.
The idea is to attach an additional pbuffer slave camera with a post render 
callback that converts the resulting image to yuv and writes it into a pipe 
to an external encoder program. Using an additional camera will ensure that 
you are free to resize the window that is displayed and that you do not rely 
on other windows not being on top of the opengl window.
Obviously it is a waste of cpu/gpu power if this is done with 60 hz. Rendering 
with 30 hz - that is omitting every second frame - for that kind of slave 
camera would be good.



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