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3b583936 1void SurveyToAlignmentExampleA(){
2 // Macro to show an example of conversion of survey data into alignment
3 // data. The position of four fiducial marks, sticked above one surface
4 // of a box is converted into the global position of the box.
5 //
7 TGeoManager *mgr = new TGeoManager("Geom","survey to alignment toy");
8 TGeoMedium *medium = 0;
9 TGeoVolume *top = mgr->MakeBox("TOP",medium,250,250,250);
10 mgr->SetTopVolume(top);
11 // make shape components
12 // ******** red outermost box ***************
13 TGeoBBox *sbox0 = new TGeoBBox(200,200,50);
14 TGeoVolume* box0 = new TGeoVolume("B0",sbox0);
15 box0->SetVisDaughters();
16 box0->SetLineColor(2); //red
18 // ******** green middle box ***************
19 TGeoBBox *sbox1 = new TGeoBBox(180,180,40);
20 TGeoVolume* box1 = new TGeoVolume("B1",sbox1);
21 box1->SetLineColor(3);//green
22 TGeoTranslation* tr = new TGeoTranslation("tr",10,0,0);
24 // ******** bleu inner box ***************
25 TGeoBBox *sbox2 = new TGeoBBox(160,160,30);
26 TGeoVolume* box2 = new TGeoVolume("B2",sbox2);
27 box2->SetLineColor(4);//bleu
29 // ******** violet innermost box ***************
30 Double_t zsize = 20.;
31 TGeoBBox *sbox3 = new TGeoBBox(140,140,zsize);
32 TGeoVolume* box3 = new TGeoVolume("B3",sbox3);
33 box3->SetLineColor(6);//violet
35
36 // Four fiducial marks on the box3, expressed in local coordinates
37 // We imagine they are at 2mm above the upper surface of the volume
38 // at the corners of a square of 200 cm side
39 const Double_t xside = 100;
40 const Double_t yside = 100;
41 const Double_t zoffset = 0.2;
42 const Double_t zdepth = zsize+zoffset;
43 Double_t A[3]={-xside,-yside,zdepth};
44 Double_t B[3]={xside,-yside,zdepth};
45 Double_t C[3]={xside,yside,zdepth};
46 Double_t D[3]={-xside,yside,zdepth};
47
48 TGeoBBox *fmbox = new TGeoBBox(1,1,1);
49 TGeoVolume* fm = new TGeoVolume("FM",fmbox);
50 fm->SetLineColor(7);//color
51 TGeoTranslation* Atr = new TGeoTranslation("Atr",-xside,-yside,zdepth);
52 TGeoTranslation* Btr = new TGeoTranslation("Btr",xside,-yside,zdepth);
53 TGeoTranslation* Ctr = new TGeoTranslation("Ctr",xside,yside,zdepth);
54 TGeoTranslation* Dtr = new TGeoTranslation("Dtr",-xside,yside,zdepth);
55
60
61 // ^ local y
62 // |
63 // D-------------|-------------C
64 // | | |
65 // | | |
66 // | | |
67 // | | |
68 // | | |
69 // | | |
70 // ------------------|------------------> local x
71 // | | |
72 // | | |
73 // | | |
74 // | | |
75 // | | |
76 // | | |
77 // A-------------|-------------B
78 //
79 // local z exiting the plane of the screen
80
81 mgr->CloseGeometry();
82 mgr->GetTopVolume()->Draw();
83 mgr->SetVisOption(0);
84 mgr->SetVisLevel(6);
85
86 Int_t i;
87 // ************* get ideal global matrix *******************
88 mgr->cd("TOP_1/B0_1/B1_1/B2_1/B3_1");
89 TGeoHMatrix g3 = *mgr->GetCurrentMatrix(); // !!don't declare g3
90 // as a pointer to mgr->GetCurrentMatrix(), mgr->cd("...")
91 // would eventually change the content pointed by g3 behind your back
92
93 // ************* get ideal local matrix *******************
94 TGeoNode* n3 = mgr->GetCurrentNode();
95 TGeoMatrix* l3 = n3->GetMatrix();
96
97 Double_t gA[3], gB[3], gC[3], gD[3]; // point coordinates in the global RS
98 g3.LocalToMaster(A,gA);
99 g3.LocalToMaster(B,gB);
100 g3.LocalToMaster(C,gC);
101 g3.LocalToMaster(D,gD);
102 cout<<endl<<"Ideal fiducial marks coordinates in the global RS:\n"<<
103 "A "<<gA[0]<<" "<<gA[1]<<" "<<gA[2]<<" "<<endl<<
104 "B "<<gB[0]<<" "<<gB[1]<<" "<<gB[2]<<" "<<endl<<
105 "C "<<gC[0]<<" "<<gC[1]<<" "<<gC[2]<<" "<<endl<<
106 "D "<<gD[0]<<" "<<gD[1]<<" "<<gD[2]<<" "<<endl;
107
108 // We apply a delta transformation to the surveyed vol box3 to represent
109 // its real position, given below by ng3 nl3, which differs from its
110 // ideal position saved above in g3 and l3
111 TGeoPhysicalNode* pn3 = mgr->MakePhysicalNode("TOP_1/B0_1/B1_1/B2_1/B3_1");
112 Double_t dphi = 3; // tilt by 3 degrees around z
113 Double_t dz = 5; // shift by 5 cm along z
114 TGeoRotation* rrot = new TGeoRotation("rot",dphi,0.,0.);
115 TGeoCombiTrans localdelta = *(new TGeoCombiTrans(0.,0.,dz, rrot));
116 // new local matrix, representing real position
117 TGeoHMatrix nlocal = *l3 * localdelta;
118 TGeoHMatrix* nl3 = new TGeoHMatrix(nlocal);
119 pn3->Align(nl3);
120
121 //Let's get the global matrix for later comparison
122 TGeoHMatrix* ng3 = pn3->GetMatrix(); //"real" global matrix, what survey sees
123 printf("\n\n************ real global matrix **************\n");
124 ng3->Print();
125 Double_t ngA[3], ngB[3], ngC[3], ngD[3];
126 ng3->LocalToMaster(A,ngA);
127 ng3->LocalToMaster(B,ngB);
128 ng3->LocalToMaster(C,ngC);
129 ng3->LocalToMaster(D,ngD);
130
131 cout<<endl<<"Fiducial marks coordinates in the global RS given by survey:\n"<<
132 "A "<<ngA[0]<<" "<<ngA[1]<<" "<<ngA[2]<<" "<<endl<<
133 "B "<<ngB[0]<<" "<<ngB[1]<<" "<<ngB[2]<<" "<<endl<<
134 "C "<<ngC[0]<<" "<<ngC[1]<<" "<<ngC[2]<<" "<<endl<<
135 "D "<<ngD[0]<<" "<<ngD[1]<<" "<<ngD[2]<<" "<<endl;
136
137
138 // From the new fiducial marks coordinates derive back the
139 // new global position of the surveyed volume
140 //*** What follows is the actual survey-to-alignment procedure which assumes,
141 //*** as is the case of the present example, 4 fiducial marks
142 //*** at the corners of a square lying on a plane parallel to a surface
143 //*** of the surveyed box at a certain offset and with
144 //*** x and y sides parallel to the box's x and y axes.
145 //*** If the code below is placed in a separate class or method, it needs
146 //*** as input the four points and the offset from the origin (zdepth)
147 //*** The algorithm can be easily modified for different placement
148 //*** and/or cardinality of the fiducial marks.
149
150 Double_t ab[3], bc[3], n[3];
151 Double_t plane[4], s;
152
153 // first vector on the plane of the fiducial marks
154 for(i=0;i<3;i++){
155 ab[i] = ngB[i] - ngA[i];
156 }
157
158 // second vector on the plane of the fiducial marks
159 for(i=0;i<3;i++){
160 bc[i] = ngC[i] - ngB[i];
161 }
162
163 // vector normal to the plane of the fiducial marks obtained
164 // as cross product of the two vectors on the plane d0^d1
165 n[0] = ab[1] * bc[2] - ab[2] * bc[1];
166 n[1] = ab[2] * bc[0] - ab[0] * bc[2];
167 n[2] = ab[0] * bc[1] - ab[1] * bc[0];
168
169 Double_t sizen = TMath::Sqrt( n[0]*n[0] + n[1]*n[1] + n[2]*n[2] );
170 if(sizen>1.e-8){
171 s = Double_t(1.)/sizen ; //normalization factor
172 }else{
173 return 0;
174 }
175
176 // plane expressed in the hessian normal form, see:
177 // http://mathworld.wolfram.com/HessianNormalForm.html
178 // the first three are the coordinates of the orthonormal vector
179 // the fourth coordinate is equal to the distance from the origin
180 for(i=0;i<3;i++){
181 plane[i] = n[i] * s;
182 }
183 plane[3] = -( plane[0] * ngA[0] + plane[1] * ngA[1] + plane[2] * ngA[2] );
184 cout<<plane[0]<<" "<<plane[1]<<" "<<plane[2]<<" "<<plane[3]<<" "<<endl;
185
186 // The center of the square with fiducial marks as corners
187 // as the middle point of one diagonal - md
188 // Used below to get the center - orig - of the surveyed box
189 Double_t orig[3], md[3];
190 for(i=0;i<3;i++){
191 md[i] = (ngA[i] + ngC[i]) * 0.5;
192 }
193
194 // The center of the box
195 for(i=0;i<3;i++){
196 orig[i] = md[i] - plane[i]*zdepth;
197 }
198 orig[1] = md[1] - plane[1]*zdepth;
199 orig[2] = md[2] - plane[2]*zdepth;
200 cout<<endl<<"The origin of the box: "<<orig[0]<<" "<<orig[1]<<" "<<orig[2]<<endl;
201
202 // get x,y local directions needed to write the global rotation matrix
203 // for the surveyed volume by normalising vectors ab and bc
204 Double_t sx = TMath::Sqrt(ab[0]*ab[0] + ab[1]*ab[1] + ab[2]*ab[2]);
205 if(sx>1.e-8){
206 for(i=0;i<3;i++){
207 ab[i] /= sx;
208 }
209 cout<<endl<<"x "<<ab[0]<<" "<<ab[1]<<" "<<ab[2]<<endl;
210 }
211 Double_t sy = TMath::Sqrt(bc[0]*bc[0] + bc[1]*bc[1] + bc[2]*bc[2]);
212 if(sy>1.e-8){
213 for(i=0;i<3;i++){
214 bc[i] /= sy;
215 }
216 cout<<endl<<"y "<<bc[0]<<" "<<bc[1]<<" "<<bc[2]<<endl;
217 }
218
219
220 // the global matrix for the surveyed volume - ng
221 Double_t rot[9] = {ab[0],bc[0],plane[0],ab[1],bc[1],plane[1],ab[2],bc[2],plane[2]};
222 TGeoHMatrix ng;
223 ng.SetTranslation(orig);
224 ng.SetRotation(rot);
225
226 cout<<"\n********* global matrix inferred from surveyed fiducial marks ***********\n";
227 ng.Print();
228
229// // To produce the alignment object for the given volume you would
230// // then do something like this:
231// // Calculate the global delta transformation as ng * g3-1
232// TGeoHMatrix gdelta = g3->Inverse(); //now equal to the inverse of g3
233// gdelta.MultiplyLeft(&ng);
234// Int_t index = 0;
235// // if the volume is in the look-up table use something like this instead:
236// // AliAlignObj::LayerToVolUID(AliAlignObj::kTOF,i);
237// AliAlignObjMatrix* mobj = new AliAlignObjMatrix("symname",index,gdelta,kTRUE);
238
239}