Are you asking us to tell you how your program is organized with respect to threads? (That's somewhat beyond the scope of the VTK mailing list.)<div><br></div><div>It sounds like your project might be better off single-threaded.<br>
<br></div><div>It would be better if you call UpdateMy3DObject from the same thread that actually does the rendering.<br><div><br></div><div><br><div class="gmail_quote">On Fri, May 15, 2009 at 10:59 AM, Giancarlo Amati <span dir="ltr"><<a href="mailto:ilferraresebono@hotmail.it">ilferraresebono@hotmail.it</a>></span> wrote:<br>
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Many thanks, <br><br>what I have is a mainWindow which has functions for rendering and then a thread that calls a kind of "UpdateMy3Dobjects" function which belongs to the mainWindow object. Now,<br>this "UpdateMy3DObjects" function works fine whenever that thread is not running while, I got the wglMakeCurrent error as soon as the thread runs the UpdateMy3Dobjects" function.<br>
So,<br>as the UpdateMy3Dobjects function calls the RenderWindow->Render() method (renderwindow buidt in a QVTKWidget object of my GUI) calling that UpdateMy3DObject from the thread does correspond to a call form a thread different from the main one?<br>
In that case if I create a global variable, boolean for example which is true when I execute the UpdateMy3DObject function and false otherwise...would it help to synchronize these threads?<br><br>I checked out on the VTK documentation and I found the vktMutexLock class....and i tried to understand the example in the documetation which is a bit difficult honestly, but,....can that class be useful for my project?<br>
<br>many kind regards.<br>Giancarlo <br><br><hr>Date: Fri, 15 May 2009 10:19:51 -0400<br>Subject: Re: [vtkusers] threads and refreshing vtkRenderWindow<br>From: <a href="mailto:david.cole@kitware.com" target="_blank">david.cole@kitware.com</a><br>
To: <a href="mailto:ilferraresebono@hotmail.it" target="_blank">ilferraresebono@hotmail.it</a><br>CC: <a href="mailto:vtkusers@vtk.org" target="_blank">vtkusers@vtk.org</a><div><div></div><div class="h5"><br><br>I will not claim to be cleverer, but I think I can answer the question:<div>
<br></div><div>Your mistake is calling vtkObjects from multiple threads without synchonization objects. In general, vtkObjects are only safely accessible by one thread at a time. Multi-thread access means you will have to use some sort of mutexes or locks to guarantee that only one thread at a time will call vtkObject methods. Furthermore, you should only attempt to call Render from the main GUI thread of your application.</div>
<div><br></div><div><br></div><div>Hope this helps,</div><div>David</div><div><br><br><div>On Fri, May 15, 2009 at 9:25 AM, Giancarlo Amati <span dir="ltr"><<a href="mailto:ilferraresebono@hotmail.it" target="_blank">ilferraresebono@hotmail.it</a>></span> wrote:<br>
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Hello vtkUSERS!!! This is an ash question for only the cleverer!! :D<br><br>I have a thread which modifies some data already in the vtkRenderWindow., now, the problem I have is when I want to refresh the window.<br>I though calling something like renderWindow->Render() or renderer->render(), but I get some error messages related to "Resource already in use" and "wglMakeCurrent()" function error.<br>
<br>Where is my mistake and any idea about how to overcome it?<br><br>Kind regards.<br><br>GC.<br><br><hr>Scrivi, parla e gioca con i tuoi amici! <a href="http://messenger.it/gioca.aspx" target="_blank">Scarica Messenger 2009!</a></div>
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