<meta http-equiv="content-type" content="text/html; charset=utf-8"><div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div><div class="h5">Hi David,</div>
</div>
<br>
It is possible to do what you are asking with vtkActors (i.e. by using a<br>
vtkPlaneSource as the data and a vtkTexture with the the image), by<br>
changing the order with which the two actors are added to the<br>
renderer. It does not make it convenient to switch them, but it makes<br>
it possible.<br>
<br>
For vtkImageActor, though, the way that the depth buffer checks are<br>
done seems to be different, and AFAIK doing an offset or using<br>
vtkImageBlend like Karthik says are the best approaches.<br>
<br>
Note that with either vtkActor or with vtkImageActor, you must set<br>
the opacity to slightly below 1.0 (e.g SetOpacity(0.995) in order to get<br>
VTK to turn on the alpha-blending in OpenGL.<br>
<font color="#888888"><br>
- David<br>
</font></blockquote></div><br></div><div>In a simple demo without any transparency, it seems to behave as John suggested, where the last image to be added takes precedence (the "top"):</div><div><br></div><div>
<meta http-equiv="content-type" content="text/html; charset=utf-8"><a href="http://www.vtk.org/Wiki/VTK/Examples/Cxx/Visualization/ImageOrder">http://www.vtk.org/Wiki/VTK/Examples/Cxx/Visualization/ImageOrder</a><div><br>
</div><div>Thanks for all of the quick information - I'll play around with it.</div><div><a href="http://www.vtk.org/Wiki/VTK/Examples/Cxx/Visualization/ImageOrder"></a><br>David</div></div>