[vtkusers] Cluster of Points and Depth Pealing

[Barth, Sebastian]

Hello vtkusers,

I've tried a lot since the last mail, but without any success.

Could someone please explain, why it is a problem to order translucent geometry and no problem to order opaque geometry?

In modern computer games this problem does not exist and even small, old and simple games don't have the order problem with translucent objects - They don't need methods like Depth Peeling and do their job much faster!

I hope you can help me!


Best Regards,

Sebastian Barth

-----Ursprüngliche Nachricht-----
Von: vtkusers-bounces at vtk.org [mailto:vtkusers-bounces at vtk.org] Im Auftrag von Barth, Sebastian
Gesendet: Freitag, 9. Juli 2010 13:41
An: vtkusers at vtk.org
Betreff: [vtkusers] Cluster of Points and Depth Pealing

Hello vtkusers,

I have a cluster of 2,000,000 points displayed by one actor and two other actors that display two planes (vtkPlaneSource) that cross that cloud of points. All actors are translucent.

To get a correct order of rendering (otherwise the cloud is rendered behind the planes), I have tried to use VTKs Death Pealing and the vtkDepthSortPolyData class. But both are too slow when rendering 2 million points.

Is there a faster way to solve my translucent order problem?
Where is the problem, modern computer games are doing it much faster?

The curious for me is that the actors are getting rendered correctly, if all are opaque or only the cloud actor is translucent. Then its points are in front or behind the opaque planes as expected.

I've attached three screenshots that show the problem (the difference is the opacity of the planes). The points are reduced to 100,000.

Hope you can help me.


Thank you and best regards,

Sebastian Barth
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