[vtkusers] error with LastRenderTimeInSeconds and OpenGL

[Lisa Avila]

Hello Doug,

My fear with adding this "fix" is that it will slow down the rendering of 
many small actors (since the pipeline will not be allowed to fill up and 
will instead be flushed many times). It is a know issue that the time is 
only an approximation. Any suggestions on how to improve this without 
slowing down the overall rendering (keeping in mind cases where there are 
1000's of actors with only a few polygons each) would be welcome.

Lisa


At 07:47 PM 2/6/2003, Doug Gehringer wrote:

>I'm seeing cases where GetLastRenderTimeInSeconds() returns a value which is
>less than the actual time to render the frame.  The render time is measured
>after the last OpenGL command has returned without a call to glFinish(). As a
>result some of the rendering time is missed.  In this case
>GetLastRenderTimeInSeconds() returns 60ms when the actual frame time is 240ms.
>
>To fix this there would need to be a call to glFinish() at the end of
>vtkOpenGLRenderer::DeviceRender().
>
>How do bugs fixes get "blessed" and entered into the mainline VTK source?
>
>
>Doug
>
>--------------------------------------------
>Doug Gehringer     x45938   Ph: 503-626-5938
>FastApps Group     Sun Microsystems Inc.
>--------------------------------------------
>
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