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<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'>Hi all:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'>I have read some mails about using Stencil Buffer in
vtk. I know the function vtkWin32OpenGLRenderWindow::</span></font><span
lang=EN-US> </span><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'>SetupPixelFormat() must be </span></font><span
lang=EN-US>overwritten. I save the buffer data to a Text file. And When I draw
an object to Stencil buffer, the result is not my desire. The code is listed below:<o:p></o:p></span></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> pCone =
vtkConeSource::New();<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> pCone->SetCenter(
-10.0 , 0.0 , 0.0 );<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> pCone->SetRadius(
2.0 );<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> pCone->SetHeight(10);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> vtkPolyDataMapper*
mapMest = vtkPolyDataMapper::New();<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> mapMest->SetInput(pSphere->GetOutput());<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> meshActot =
vtkOpenGLActor::New();<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> meshActor->SetMapper(mapMest);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> meshActor->GetProperty()->SetColor(1,0,0);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> ren1 = new
vtkOpenGLRenderer;<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> ren1->AddActor(
meshActor );<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> renWin = new
vtkWin32OpenGLRenderWindow;<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> renWin->AddRenderer(ren1);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> iren =
vtkRenderWindowInteractor::New();<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> iren->Initialize();<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> glClear
(GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT|GL_COLOR_BUFFER_BIT);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> glEnable(GL_STENCIL_TEST);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> glStencilFunc(GL_ALWAYS,1,1);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> glStencilOp(GL_KEEP,GL_REPLACE,GL_REPLACE);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> renWin->Render();<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'> iren->Start();<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-indent:21.0pt'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>float
pSphereZBuffer[WINDOW_SIZE*WINDOW_SIZE];<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'> glDisable(
GL_TEXTURE_2D );<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'> glDisable(
GL_SCISSOR_TEST );<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'> glPixelStorei(
GL_PACK_ALIGNMENT, 1 );<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'> glReadPixels( 0, 0, <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'>
WINDOW_SIZE, WINDOW_SIZE,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'>
GL_STENCIL_INDEX, GL_FLOAT,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'>
pSphereZBuffer );<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'> ofstream
file("zbuffer1.txt");<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'> for(i
= 0 ; i < WINDOW_SIZE ; i++ )<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'> {<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'> for(j
= 0 ; j < WINDOW_SIZE ; j++ )<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'> file<<setprecision(0)<<setw(4)<<pSphereZBuffer[WINDOW_SIZE*i+j];<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'> file<<endl;<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-indent:21.0pt'><font size=1 face=Arial><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>}<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'> file.close();<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'>The result is not right. But When these codes are
moved in the front of the function </span></font><span lang=EN-US>renWin->Render(),
the result is right.<o:p></o:p></span></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> glClear
(GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT|GL_COLOR_BUFFER_BIT);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> glEnable(GL_STENCIL_TEST);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> glStencilFunc(GL_ALWAYS,1,1);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> glStencilOp(GL_KEEP,GL_REPLACE,GL_REPLACE);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'>just like that, the function vtkOpenGLRenderWindow::Render
is overwritten.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'>vtkMYOpenGLRenderWindow ::Render()<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'>{<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> glClear
(GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT|GL_COLOR_BUFFER_BIT);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> glEnable(GL_STENCIL_TEST);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> glStencilFunc(GL_ALWAYS,1,1);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=EN-US
style='font-size:10.5pt'> glStencilOp(GL_KEEP,GL_REPLACE,GL_REPLACE);<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'> ¡¡¡¡..<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'> ¡¡¡¡¡.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'>}<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Arial><span lang=EN-US style='font-size:
9.0pt;font-family:Arial'>Who can tell me the reason? <o:p></o:p></span></font></p>
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