Hi, I am trying to disable/enable hardware acceleration via a GUI of my program. How is that possible ? Can I use VTK or do I need plain OpenGL stuff ? greets Ingo --- Dr.-Ing. Ingo H. de Boer Polytec GmbH Polytec-Platz 1-7, 76337 Waldbronn, Germany phone: ++49 7243 604 106 fax : ++49 7243 604 255