<div dir="ltr">Hello all, <br>I have a question about threading and VTK. Specifically, about how I can have a renderWindow that can be updated either from a renderWindowInteractor running on one thread, or from a separate worker thread. <br>
<br>In more detail, I'm doing some image registration work (using ITK), and I would like to use VTK to visualize the progress of the registration at every n'th iteration. So far, no problem. But I would also like to be able to interact with the visualization window at the same time, for example to rotate the viewpoint as it progresses. To make this work, what I've done is to have my registration code running in its own thread and then launch an interactor on the main one. At each iteration, the registration code calls SetPosition on the appropriate vtkActor. So far, all of this works fine, and if I interact with the renderWindow (for example click and drag the mouse), the renderWindow redraws, picking up the changes that my registration code has made to the actor's position.<br>
<br>What I can't figure out how to do is to have the registration code safely tell the renderWindow to re-render itself without me interacting with the window. I can't for example call window->Render() directly from the registration thread without causing errors. My best guess as to why comes from this note:<br>
<a href="http://public.kitware.com/pipermail/vtkusers/2003-December/070728.html" target="_blank">http://public.kitware.com/pipermail/vtkusers/2003-December/070728.html</a><br>which explains that trying to use the same OpenGL context across two threads is a big no-no, and that seems to be exactly what I'm doing when I go that route. So I need to make sure that the Render call is always made from the main thread, but I don't know how to make that happen, and any tips from the community will be greatly appreciated.<br>
<br>Thanks so much,<br>Jaety<br></div>