“1 OpenGL errors detected 0 : (1285) Out of memory” after tens of thousands of Loop (inside each Loop: new Window, Render, VolumeMapper then delete them))
Duplicate of vtk-8.1 has GPU memory leak? esp. on Linux. the related class is vtkXOpenGLRenderWindow.
Please do not re-post the same question (or, if these are different, the details are not enough to tell that they are separate).