Re: Re: Different displays of TGeo Union in TPad/X3D and OpenGL

From: Brett Viren <bv_at_bnl.gov>
Date: Thu, 15 Feb 2007 15:01:26 -0500

Hi again,

Andrei Gheata <Andrei.Gheata_at_cern.ch> writes:

> No, this is not a feature, but a bug related to the visualization of
> this shape in GL. Visualization of TGeo composite shapes was
> implemented quite long ago by Timur Pocheptsov (the end remark in the
> class docs is no longer valid). Looks like some matrix it passed in a
> wrong way to GL interface, this is why you see the gap. I wonder if
> Timur can look into it. A geometry definition made with a simple macro
> (not by conversion via VGM) would also help.

I saved the problematic geometry as a .C file (appended). When re-running it, the OpenGL artifact remains, so it is useful as a pure-ROOT demonstration of the problem. I tried running this on some older releases and find:

  5.14/00 - fails
  5.12/00 - fails
  5.11/02 - okay.

The only strangeness in the generated macro itself that I could see is that some of the TGeoRotations are given empty strings for names. Adding in non-empty names had no effect. The appended file has these empty strings filled in. It isn't clear to me why these rotations are there in the first place as there are no rotations in the original geometry.

-Brett.

// --- pmt.C showing OpenGL artifact --- // /* run like:

 root -l pmt.C
 top = gGeoManager->GetTopVolume()
 top->Draw()
 Menu: "View"->"View With"->"OpenGL"

*/

void pmt() {

   gSystem->Load("libGeom");
   new TGeoManager("VGM Root geometry", "VGM Root geometry");

   Double_t dx,dy,dz;
   Double_t dx1, dx2, dy1, dy2;
   Double_t vert[20], par[20];
   Double_t theta, phi, h1, bl1, tl1, alpha1, h2, bl2, tl2, alpha2;
   Double_t twist;
   Double_t origin[3];
   Double_t rmin, rmax, rmin1, rmax1, rmin2, rmax2;
   Double_t r, rlo, rhi;
   Double_t phi1, phi2;
   Double_t a,b;
   Double_t point[3], norm[3];
   Double_t rin, stin, rout, stout;
   Double_t thx, phx, thy, phy, thz, phz;
   Double_t alpha, theta1, theta2, phi1, phi2, dphi;
   Double_t tr[3], rot[9];
   Double_t z, density, radl, absl, w;
   Double_t lx,ly,lz,tx,ty,tz;
   Double_t xvert[50], yvert[50];
   Double_t zsect,x0,y0,scale0;

   Int_t nel, numed, nz, nedges, nvert;
   TGeoBoolNode *pBoolNode = 0;

// MATERIALS, MIXTURES AND TRACKING MEDIA
// Material: Air

   a       = 12.006700;
   z       = 7.000000;
   density = 0.001205;
   radl    = 26914.614250;
   absl    = 0.000000;

   pMat1 = new TGeoMaterial("Air", a,z,density,radl,absl);    pMat1->SetIndex(0);
// Medium: Air

   numed   = 0;  // medium number
   par[0]  = 0.000000; // isvol
   par[1]  = 0.000000; // ifield
   par[2]  = 0.000000; // fieldm
   par[3]  = 0.000000; // tmaxfd
   par[4]  = 0.000000; // stemax
   par[5]  = 0.000000; // deemax
   par[6]  = 0.000000; // epsil
   par[7]  = 0.000000; // stmin

   pMed1 = new TGeoMedium("Air", numed,pMat1, par); // Material: Water

   a       = 1.007970;
   z       = 1.000000;
   density = 1.000000;
   radl    = 57.838822;
   absl    = 0.000000;

   pMat5 = new TGeoMaterial("Water", a,z,density,radl,absl);    pMat5->SetIndex(4);
// Medium: Water

   numed   = 4;  // medium number
   par[0]  = 0.000000; // isvol
   par[1]  = 0.000000; // ifield
   par[2]  = 0.000000; // fieldm
   par[3]  = 0.000000; // tmaxfd
   par[4]  = 0.000000; // stemax
   par[5]  = 0.000000; // deemax
   par[6]  = 0.000000; // epsil
   par[7]  = 0.000000; // stmin

   pMed5 = new TGeoMedium("Water", numed,pMat5, par);

// TRANSFORMATION MATRICES
// Combi transformation:

   dx = 0.000000;
   dy = 0.000000;
   dz = -5.000000;

// Rotation:

   thx = 90.000000;    phx = 0.000000;
   thy = 90.000000;    phy = 90.000000;
   thz = 0.000000;    phz = 0.000000;

   TGeoRotation *pMatrix7 = new TGeoRotation("pMatrix7",thx,phx,thy,phy,thz,phz);    pMatrix6 = new TGeoCombiTrans("pMatrix6", dx,dy,dz,pMatrix7);
// Shape: bigbox type: TGeoBBox

   dx = 20.000000;
   dy = 20.000000;
   dz = 20.000000;

   TGeoShape *pbigbox_1 = new TGeoBBox("bigbox", dx,dy,dz);
// Volume: bigbox

   pbigbox_8446548 = new TGeoVolume("bigbox",pbigbox_1, pMed1);    pbigbox_8446548->SetVisLeaves(kTRUE);

// SET TOP VOLUME OF GEOMETRY

   gGeoManager->SetTopVolume(pbigbox_8446548);

// SHAPES, VOLUMES AND GEOMETRICAL HIERARCHY
// Shape: bulb type: TGeoSphere

   rmin   = 11.500000;
   rmax   = 12.500000;
   theta1 = 0.000000;
   theta2 = 66.421822;
   phi1   = 0.000000;
   phi2   = 360.000000;

   TGeoShape *pbulb_2 = new TGeoSphere("bulb",rmin,rmax,theta1, theta2,phi1,phi2);
// Shape: butt type: TGeoSphere

   rmin   = 11.500000;
   rmax   = 12.500000;
   theta1 = 113.578178;
   theta2 = 156.421822;
   phi1   = 0.000000;
   phi2   = 360.000000;

   TGeoShape *pbutt_3 = new TGeoSphere("butt",rmin,rmax,theta1, theta2,phi1,phi2);
// Shape: base type: TGeoTubeSeg

   rmin = 4.000000;
   rmax = 5.000000;
   dz   = 3.500000;
   phi1 = 0.000000;
   phi2 = 360.000000;

   TGeoShape *pbase_4 = new TGeoTubeSeg("base",rmin,rmax,dz,phi1,phi2);
// Combi transformation: boolean_butt_base

   dx = 0.000000;
   dy = 0.000000;
   dz = -14.956439;

// Rotation:

   thx = 90.000000;    phx = 0.000000;
   thy = 90.000000;    phy = 90.000000;
   thz = 0.000000;    phz = 0.000000;

   TGeoRotation *pMatrix3 = new TGeoRotation("pMatrix3",thx,phx,thy,phy,thz,phz);    pMatrix2 = new TGeoCombiTrans("boolean_butt_base", dx,dy,dz,pMatrix3);    pBoolNode = new TGeoUnion(pbutt_3,pbase_4,0,pMatrix2);
// Shape: boolean_butt_base type: TGeoCompositeShape
   TGeoShape *pboolean_butt_base_5 = new TGeoCompositeShape("boolean_butt_base", pBoolNode);    pboolean_butt_base_5->SetTitle("butt+base:boolean_butt_base");
// Combi transformation: boolean_bulb_boolean_butt_base

   dx = 0.000000;
   dy = 0.000000;
   dz = 10.000000;

// Rotation:

   thx = 90.000000;    phx = 0.000000;
   thy = 90.000000;    phy = 90.000000;
   thz = 0.000000;    phz = 0.000000;

   TGeoRotation *pMatrix5 = new TGeoRotation("pMatrix5",thx,phx,thy,phy,thz,phz);    pMatrix4 = new TGeoCombiTrans("boolean_bulb_boolean_butt_base", dx,dy,dz,pMatrix5);    pBoolNode = new TGeoUnion(pbulb_2,pboolean_butt_base_5,0,pMatrix4);
// Shape: boolean_bulb_boolean_butt_base type: TGeoCompositeShape
   TGeoShape *pboolean_bulb_boolean_butt_base_6 = new TGeoCompositeShape("boolean_bulb_boolean_butt_base", pBoolNode);    pboolean_bulb_boolean_butt_base_6->SetTitle("bulb+boolean_butt_base:boolean_bulb_boolean_butt_base");
// Volume: bulb

   pbulb_8440f00 = new TGeoVolume("bulb",pboolean_bulb_boolean_butt_base_6, pMed5);    pbulb_8440f00->SetVisLeaves(kTRUE);
   pbigbox_8446548->AddNode(pbulb_8440f00, 0, pMatrix6);

// CLOSE GEOMETRY

   gGeoManager->CloseGeometry();
} Received on Thu Feb 15 2007 - 21:03:56 CET