Hello Mike this sounds to define the detector geometry you should not use TPolyMarker3D
rather http://root.cern.ch/root/htmldoc/TPolyLineShape.html#TPolyLineShape:description
The last one is derived from TShape and can be easily incorporated
into either TNode or TVolume structures.
Hope this helps, With my regards, Valeri
----- Original Message -----
From: "Rene Brun" <Rene.Brun@cern.ch>
To: "Mike Miller" <miller@star.physics.yale.edu>
Cc: <roottalk@cern.ch>
Sent: Friday, June 22, 2001 4:49 AM
Subject: Re: [ROOT] Possible bug?
> Hi Mike,
>
> Several objects (including TPolyMarker3D) are automatically deleted when
> the pad is redrawn (your case). your pointer poly points to an invalid object.
> There are two solutions to this problem.
> 1- Replace the statement
> TPolyMarker3D* poly = new TPolyMarker3D(9, x, 8);
> by
> TPolyMarker3D* poly = new TPolyMarker3D();
> poly->SetPolyMarker(9, x, 8);
>
> 2- do:
> TPolyMarker3D* poly = new TPolyMarker3D(9, x, 8);
> poly->ResetBit(kCanDelete);
>
> The bit kCanDelete is not set by the default constructor.
>
> Rene Brun
>
>
>
> Mike Miller wrote:
> >
> > Hello, I'm trying to draw a TPolyMarker3D on top of a set of TVolumes. I
> > do this to draw a set of hits on top of a simple detector model. If I
> > draw the TVolume, the TPolyMarker3D, the TVolume agiain, I'm ok. If I
> > draw the TVolume, TPolyMarker3D, TVolume agiain, TPolyMarker3D again, I
> > seg-fault. In this example I wouldn't need to draw the TVolume multiple
> > times, it is simply meant to illustrate the point. However, in the real
> > application, I do need to call TVolume::Draw() more than once to refresh
> > changes in the display.
> >
> > Here's the macro...
> >
> > void TestShapes()
> > {
> > gSystem->Load("libstar");
> > TCanvas* c1 = new TCanvas("c1");
> >
> > TVolume* main = new TVolume();
> >
> > TBRIK* brik = new TBRIK("BRIK","BRIK","void", 10., 20., 30.);
> > TVolume* son = new TVolume("son","son",brik);
> >
> > main->Add(son);
> >
> > cout <<"Draw Main Volume"<<endl;
> > main->Draw();
> > c1->Update();
> >
> > main->SetVisibility(TVolume::kBothVisible);
> >
> > cout <<"Starting Loop To Fill Array"<<endl;
> > double* x = new double[9];
> > for (int i=0; i<9; ++i) {
> > x[i]=static_cast<double>(i);
> > }
> >
> > for (int i=0; i<9; ++i) {
> > cout <<i<<"\t"<<x[i]<<endl;
> > }
> >
> > TPolyMarker3D* poly = new TPolyMarker3D(9, x, 8);
> > cout <<"Draw TPolyMarker3D"<<endl;
> > poly->Draw();
> > cout <<"Draw TPolyMarker3D Again"<<endl;
> > poly->Draw();
> > cout <<"Draw Main Volume Again"<<endl;
> > main->Draw();
> > cout <<"Update Canvas"<<endl;
> > c1->Update();
> >
> > file://This is where we seg-fault
> > cout <<"Draw TPolyMarker3D Again"<<endl;
> > poly->Draw();
> >
> > return;
> > }
> >
> > How else can I represent points in an inexpensive 3d fashion? Thanks,
> > Mike
> >
> > Michael L. Miller
> > Yale Physics
> > michael.miller@yale.edu
> >
> > BNL: (631) 344-8342
> > Building 118
> > Yale Software
> >
> > Yale: (203) 432-5637
> > Room 305 WNSL
>
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