Changeset 1614 for trunk/MagicSoft/Simulation/Detector/ReflectorII/ph2cph.c

Timestamp:

11/14/02 21:39:04 (22 years ago)

Author:

bigongia

Message:

*** empty log message ***

File:

• trunk/MagicSoft/Simulation/Detector/ReflectorII/ph2cph.c (modified) (7 diffs)

trunk/MagicSoft/Simulation/Detector/ReflectorII/ph2cph.c

@@ -118 +118 @@
   r[0] = ph->u; 
   r[1] = ph->v; 
-  r[2] = (float) sqrt(1.0 - r[0]*r[0] - r[1]*r[1]);
+
+// AM 11/2002: fixed line below: u v are the direction cosines of the 
+// *downgoing* photon. Hence, third component must be negative!
+// This was a serious bug affecting all versions before 0.6 (see TDAS 
+// note on Reflector program 0.6).
+
+  r[2] = (float) -sqrt(1.0 - r[0]*r[0] - r[1]*r[1]);
 
   /* get photon time and production height */    
@@ -494 +500 @@
   /* 
    if we still have the photon, we continue with the reflexion;        
-   we calculate normal vector in this point 
-   (and normalize, with the sign changed)
+   we calculate normal vector in this point and normalize:
   */ 
 
   rnor[0] = 2.0f*xcut[0];
   rnor[1] = 2.0f*xcut[1];
-  rnor[2] = (float) (2.0*(xcut[2] - 2.0*ct_Focal[i_mirror]));
+  rnor[2] = (float) (2.0*(xcut[2] - 2.0*ct_data[i_mirror].f));
 
   /* CBC */
@@ -506 +511 @@
   /* CBC */ 
 
-  rnorm    = -NORM( rnor );
+// Changed AM, 11/2002: now we use the normal vector going "outwards" 
+// from inside the sphere (=removed minus sign in normalization below).
+// It is easier to do so, since now the vector rm indicating the 
+// photon direction also goes from the front to the back of the mirror.
+
+  rnorm    = NORM( rnor );
   rnor[0] /= rnorm;
   rnor[1] /= rnorm;
@@ -525 +535 @@
   */ 
 
-  calpha = (float) fabs(rnor[0]*rm[0] + rnor[1]*rm[1] + rnor[2]*rm[2]);
+// AM 11/2002: removed absolute value in scalar 
+// product below (it is now unnecessary):
+
+  calpha = (float) (rnor[0]*rm[0] + rnor[1]*rm[1] + rnor[2]*rm[2]);
 
   /* CBC */
@@ -532 +545 @@
         
   /*  finally!!! we have the reflected trajectory of the photon */ 
+
 
   rrefl[0] = (float) (2.0*rnor[0]*calpha - rm[0]);
@@ -633 +647 @@
    calculate angle of incidence between tray. and camera plane
    the camera plane is
-   0 y + 0 y + z - ct_Focal = 0 => (A,B,C,D) = (0,0,1,-ct_Focal)
+   0 x + 0 y + z - ct_Focal_mean = 0 => (A,B,C,D) = (0,0,1,-ct_Focal_mean)
    from Table 3.20 "Tasch. der Math."
   */ 
@@ -679 +693 @@
   /* Output */ 
 
-/*  cph->w   = wl;  */
-  cph->x   = xcam[0];
-  cph->y   = xcam[1];
+  /* AM Nov 2002: Added one further change of coordinates so that the camera 
+   * images have the "right" orientation: they will appear as seen by an 
+   * observer on ground, standing behind the mirror dish and looking towards 
+   * the camera. Formerly cph->x and cph->y were simply xcam[0] and xcam[1].
+   */
+
+  cph->x   = -xcam[1];
+  cph->y   = -xcam[0];
+
   cph->u   = r[0];
   cph->v   = r[1];