<div class="gmail_quote"><span dir="ltr"></span>Hi,<br><div> <br>Let
me first describe the set-up. I'm using a quad core, linux box with vtk
5.4. I'm using Qt for GUI, thus QVTKWidget. I'm trying to visualize
image frames (1280 x1280 pixels) being captured from a camera device.
The anticipated frame rate is 30 fps. I've 'capture frame' functionality
happening in a separate thread. A minimal vtk pipeline is set up using
vtkImageData, vtkImageMapper, vtkActor2D. Each time a new frame arrives,
update is callled on the vtk pipeline and the main thread running Qt,
is notified to perform render operation using paint event of QVTKWidget.
For synchronization, mutex is used. This setup seems to work just fine
except from the performance predictability standpoint.I've put timers in
place to measure time taken for each step.<br><br>The problem is, the paint call (or eventually 'render' call) is not
behaving deterministically. For some frames, render completes within
6-10 milliseconds, but for others, inexplicably, it starts taking 50-70
milliseconds!! Now with new frame arriving at every 33 milliseconds (30
fps), I start loosing frames. I've tried the setup using vtkImageActor
(therefore without vtkImageMapper, vtkActor2D) as well, but with similar
behavior. <br><br>I don't understand why is render taking 60-70 milliseconds? The data
is ready to be rendered. The in-deterministic aspect is even more
worrying.<br><br>Can someone please help? It'll be greatly appreciated.<br><br>regards<font color="#888888"><br>Siddharth<br>
</font></div></div>