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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>OK,<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>I realize now that my Callback function should have looked more like this (note the glPushAttrib, glPopAttrib before and after the Render call):<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>void Callback()<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>{<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> glPushMatrix();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> glBegin( GL_TRIANGLES );<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> glColor3f( 1.0f, 0.0f, 0.0f ); glVertex3f( 0.2f, 1.0f, 0.0f );<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> glColor3f( 1.0f, 0.0f, 0.0f ); glVertex3f( 1.07f, -0.5f, 0.0f );<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> glColor3f( 1.0f, 0.0f, 0.0f ); glVertex3f( -0.67f, -0.5f, 0.0f );<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> glEnd();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> glPopMatrix();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> glPushMatrix();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> glPushAttrib(GL_ALL_ATTRIB_BITS);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> </span><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas'>m_Renderer->Render();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas'> glPopAttrib();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas'> glPopMatrix();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas'>}<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal><span lang=DE-CH style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=DE-CH style='color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> vtkusers-bounces@vtk.org [mailto:vtkusers-bounces@vtk.org] <b>On Behalf Of </b>Bryn Lloyd<br><b>Sent:</b> Tuesday, May 31, 2011 4:45 PM<br><b>To:</b> vtkusers@vtk.org<br><b>Subject:</b> [vtkusers] Render using Multipass (vtkRenderstate / vtkRenderPass) framework, in an existing OpenGL context<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Hi<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I have been trying to write some code, which allows me to use some of the rendering methods in VTK within an existing context, with direct calls to OpenGL done before the VTK render call.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>It seems the nice Multipass framework by François Bertel (http://cmake.org/Wiki/VTK/MultiPass_Rendering) could be used for this purpose. I tried following code (see below). However, if run an example which plots two triangles – one directly using OpenGL – one using a vtkPolyData+Mapper+Actor, then the final color of the triangles is always set by the color property of the vtkActor, even if I set a different color in the direct OpenGL code.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Does anybody have an idea what I am doing wrong here?<o:p></o:p></p><p class=MsoNormal>Is there a nice example somewhere, which uses the Multipass framework mixed with a different rendering library/OpenGL code?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks!<o:p></o:p></p><p class=MsoNormal>Bryn<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>void Setup()<o:p></o:p></p><p class=MsoNormal>{<o:p></o:p></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> </span><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas;color:green'>// Setup renderer and render window</span><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas'><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas'> m_Renderer = vtkRenderer::New();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> m_RenderWindow = vtkWin32OpenGLRenderWindow::New();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> m_RenderWindow->SetWindowId(WindowId);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> m_RenderWindow->SetParentId(ParentId);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> m_RenderWindow->SetContextId((HGLRC)ContextId);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> m_RenderWindow->SetDeviceContext((HDC)DeviceContext);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> m_RenderWindow->AddRenderer(m_Renderer);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> vtkOpaquePass * opaquePass = vtkOpaquePass::New();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> vtkLightsPass * lights = vtkLightsPass::New();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> vtkRenderPassCollection * opasses = vtkRenderPassCollection::New();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> passes->AddItem(lights);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> passes->AddItem(opaquePass);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> vtkSequencePass * seq = vtkSequencePass::New();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> seq->SetPasses(passes);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> m_Renderer->SetPass(seq);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>}<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>The callback function is:<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>void Callback()<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>{<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> glPushMatrix();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> glBegin( GL_TRIANGLES );<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> glColor3f( 1.0f, 1.0f, 1.0f ); glVertex3f( 0.2f, 1.0f, 0.0f );<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> glColor3f( 1.0f, 1.0f, 1.0f ); glVertex3f( 1.07f, -0.5f, 0.0f );<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> glColor3f( 1.0f, 1.0f, 1.0f ); glVertex3f( -0.67f, -0.5f, 0.0f );<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> </span><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas'>glEnd();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas'> glPopMatrix();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas'> glPushMatrix();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas'> m_Renderer->Render();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=DE-CH style='font-size:9.5pt;font-family:Consolas'> </span><span style='font-size:9.5pt;font-family:Consolas'>glPopMatrix();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>}<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>