[vtkusers] vtkClipVolume is quite slow

[Chunyan Jiang]

Hi, all,
I render a data set object. And I would like to go through the object by
clipping plane. So I use vtkClipVolume. It can work now. However, every time
when I set the clip plane and render the clipped object, it is very slow.
Before I use OpenGL to realize it by glClipPlane(GL_CLIP_PLANE0,Plane). It
is very fast comparing with vtk. Why does vtkClipVolume is so slow or did I
do something wrong. The following is the code paragraph of both vtk and
OpenGL:
----------------------------------------------------------------------------
----------------------------
		ClipVolume=vtkClipVolume::New();
		ClipVolume->SetInput(Data);
		ClipVolume->SetClipFunction(ClipPlane);
		ClipVolume->GenerateClipScalarsOff();
		DataMapper=vtkDataSetMapper::New();
		DataMapper->SetInput(ClipVolume->GetOutput());
		DataMapper->ImmediateModeRenderingOn();

		DataActor=vtkActor::New();
		DataActor->SetMapper(DataMapper);

		ren1->AddActor(DataActor);
----------------------------------------------------------------------------
----------------------------
	List=glGenLists(1);
	glNewList(List,GL_COMPILE);
	glPushAttrib(GL_CURRENT_BIT);
       .
       .
       .
       .
	glPopAttrib();
	glEndList();
	glClipPlane(GL_CLIP_PLANE0,Plane);
	glEnable(GL_CLIP_PLANE0);

	glCallList(List);

	glDisable(GL_CLIP_PLANE0);
----------------------------------------------------------------------------
----------------------------

Any suggestion is very appreciated. Thanks in advance!

Chunyan
***********************************************************************
Chunyan Jiang, Dipl.-Inform.,
Institut for Telematic
Bahnhofstrasse 30-32, D-54292 Trier, Germany
Phone: (+49) (0)651-97551-34
Fax: (+49) (0)651-97551-12
***********************************************************************