[Paraview] Off Screen Rendering

[Paul Melis]

Hi,

This is an old post, to which I replied at the time, but now that I'm
rereading it I'm wondering whether the summary below was correct?

On 11/26/2009 07:50 AM, chew ping wrote:
>
> so based on the timer log results that i collected, what i read about
> offscreen-rendering and the explanation below, can i conclude the
> followings? someone pls correct me if i'm wrong!
>
> with --use-offscreen-rendering
>
>     * X windows are disabled on all server processes
>     * all server processes render the geometry locally
>     * then each server processes sends the image to the client for
>       compositing
>     * there's NO data gathering to process 0, meaning the master
>       doesn't collect all images from each processes for composting,
>       then only send it to the client for rendering
>
Assuming a non-Mesa version of Paraview that is run with
--offscreen-rendering what happens w.r.t. compositing? Are the images
rendered by the pvserver processes indeed sent to the *client* for
compositing? Or is process 0 responsible for compositing, followed by
forwarding the final image to the client?
>
>     * that's why --use-offscreen-rendering is faster
>
>
>
> without --use-offscreen-rendering
>
>     * X windows are enabled on all server processes
>     * all server processes the raw data, then send all geometry to
>       process 0
>     * process 0 gather all geometry then send them to the client to render
>     * the client does all the rendering job
>
Why would the client do all the rendering in this case? Assuming an
amount of data over the local rendering threshold why would the
pvserver's not each render their part and send out images for
compositing? What has the choice of offscreen/non-offscreen rendering to
do with it?

Thanks,
Paul