Eve does not display Tubes

ROOT
1

In the following example code, if I create a box Eve displays it. If I create a tube, I get a blank screen

 gSystem->Load("libGeom");
   auto geom = new TGeoManager("Assemblies", "Geometry using assemblies");
   auto Al = new TGeoMedium("Aluminium",2, new TGeoMaterial("Al", 26.98,13,2.7));
   TGeoVolume *vol = geom->MakeTube("TUBE",Al, 20,30,40);
   geom->SetTopVolume(vol);
   geom->CloseGeometry();
   TEveManager::Create();
gEve->AddGlobalElement(new TEveGeoTopNode(geom, geom->GetTopNode()));
   gEve->Redraw3D(kTRUE);

Substiute

TGeoVolume *vol= geom->MakeBox("TOP",Al,100,100,100);

and it works fine.

_ROOT Version:6.24.00
_Platform:Linux
Compiler: Not Provided

2

@matevz probably can help you

3

Strange, I cut-n-pasted your code into root and it came up with this:

geo-tube
geo-tube1024×768 79.9 KB

I wonder what could be going wrong? :slight_smile: If you type ‘d’ in the gl viewer to show the debug boxes, does it show a green box (this the global bounding box determined by the viewer)?

Cheers,
Matevz

4

Yes, I have a bounding box. Everything appears fine apart from the tube not appearing!

5

As a test I logged into the same machine from my windows laptop using MobaXterm and did the same test and it worked! Something subtle to do with my drivers it seems.

6

I do get some errors when I run this but as everything else works I have been ingoring them. I get
TEveManager::Create();
libGL error: No matching fbConfigs or visuals found
libGL error: failed to load driver: swrast
I googled this and got a whole range of conflicting or irrelevant answers so I think I’ll have to live with it.
Any way if it is just a problem with my ancient laptop’s graphics its not worth you spending time on it. I have a work around. I create a cylinder using TGeoXtru which works fine.

7

Hi Alex,

Ah, I know now! :slight_smile: It’s the size of display lists using vertex arrays that bothers some (old?) intel mesa and fglrx drivers.

Try setting these to 0 in your rootrc:
OpenGL.UseDisplayListsForVertexArrays: 0
and if it still gives you trouble also this:
OpenGL.UseDisplayLists: 0

No matching fbConfigs or visuals found could mean you have no stencil buffer or non-24-bit color buffers, depth buffer is usually ok (I think we require 16 bit) … what does glxinfo show?
Strange that it works anyway, usually when it says this nothing works. Anyway, hope I haven’t hexed you by telling it :slight_smile:

Cheers,
Matevz

8

Unfortunately that didn’t help. Here is the glxinfo ouput
glxinfo.txt (55.5 KB)

9

Rats, I’m out of ideas. The GL visuals look good, it’s strange it’s complaining.

Oh, could this be it? That you have some leftover libGL from mesa that gets in the way? glxinfo says you are using nvidia drivers.

10

I already tried the suggestions in that thread. No luck. Thanks for trying.

11

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