vtkAppendPolyData ?

ParaView Support
1

Hi
I am absolutely new to Paraview and only using its Qt-viewer. The solids are being generated by another application (GEANT4).
So I generated one cone and another hollow cone surrounding the first cone. When I form a union I should see a merged single cone.
However, when I try to open that wrl file, I get the following error.
The error is:
vtkCompositeDataPipeline (0x61652d0): Input port 0 of algorithm vtkAppendPolyData(0x5064a70) has 0 connections but is not optional.

I have no idea what to do. I Googled for solutions and looks like there are ways to figure this out using C++ scripts. But is there a way to resolve this on the Paraview viewer that I am using?

Another fact: when I do make a truncated cone, where it is truncated at the apex, then everything works. So looks like union at the apex is failing for whatever reasons.

Any help here is appreciated

2

So the .wrl file is generated by GEANT4?

Can you share it here ?
Do you have other .wrl file that works ?

Here is one that do if that’s helps you.bot2.wrl (50.7 KB)

3

Hello Mathieu
Here is a file that works:
g4_lens_using_pairofsolids_to_boolean.wrl (65.7 KB)
For example, part of this is a lens made using 2 pairs of hollow cones. Although the title says ‘boolean’, no booleans were created in this example purposely.
But I can create boolean of two solids pair wise it works and is similar to this solid i.e., boolean(solidA+solidB =E) and boolean(solidC+solidD=F) shows visually as G=[E;F] i.e., two separate booleans side-by-side.

Here is a file that does NOT work:
g4_unionofbooleans.wrl (129 Bytes)
And this solid is like previous but is made using two pairs (A+B and C+D) to generate two booleans (A+B=E and C+D=F) and then union of these two booleans(E+F=G) to create a final boolean lens (G) very similar to the previous.
However, this one shows the error I mentioned and I do not see it on the Paraview veiwer.

Thanks for your help.

4

Hello Mathieu
Can you also explain what is bot2.wrl supposed to be and how it can help me?
Thank you

5

Hi Matheu
Yes I am able to visualize bot2.wrl but not sure what does that imply?
Thanks

6

Just an example for a working file.

your non-working file is almost empty and does not contain a geometry :

#VRML V2.0 utf8
# Generated by VRML 2.0 driver of GEANT4


#---------- CAMERA
Viewpoint {
  position 0 0 3936.73
}

#End of file.
7

Yes correct! Whenever I try to create solids which are boolean of two boolean solids I get nothing - an empty file.
No idea why? I will explore to see if its a problem with GAMOS or GEANT which generates the solid.
Thanks

8

BTW, in Paraview UI, is there a way to generate union of two solids. I could create two merged solids but I am not able to create an intersection solid or from them.
Thanks

9

A bug/missing feature in GEANT most likely.

BTW, in Paraview UI, is there a way to generate union of two solids. I could create two merged solids but I am not able to create an intersection solid or from them.

There is a filter in VTK called vtkBooleanOperationPolyDataFilter, but it is not exposed in ParaView. You could write a simple XML plugin to expose it.