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TGeomanager GDML hole on a pad with OpenGL

Hi all,
I have a simple geometry to show with openGL.
It is a trap pad with two holes on it. The problem is they look different from
different angles. It seems one of the holes are not through but with a thin layer
on one end.
Is this just a display problem? Or how can I avoid this?
Thanks a lot.

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Hi,

It would help if you can provide geometry file.

Regards,
Sergey

Hi Sergey,
Thanks for the quick response.
It is a huge file, and I choose this single volume to display with open GL.
Here is the code for the related part.
It seems when I increase the thickness of the pad(z in _STMShield_front_Al0x32a72a0), everything looks fine.
But I do need to keep this small.

code:code.txt (1.1 KB)

It looks similar to ROOT-7981.

Hi,

First of all, here is complete gdml file for testing.
work.gdml.txt (1.8 KB)

And yes - seems to be ROOT geometry rendering has problem in correct visualization of such composites. But composite itself looks fine. If I check it with JSROOT - works correctly:

Volume
All components

There is no touching surfaces - everywhere clear cuts.
I fear this bug will be difficultly to fix.

Regards,
Sergey

Here problem with “complicated” composite shape. It has very many components and CSG algorithm just breaks calculation at some complexity level. As a result - one gets incomplete and partially corrupted sets of triangles. Unfortunately JSROOT has similar problem as well with that geometry.

1 Like

Hi Sergey,

Thanks for completing the gdml file.
This file works good in ROOT.
Then, I think the problem only happens when this composite is nested in another big geometry.

Yaqian