<div dir="ltr"><div>Hi everyone, <br><br>I'm trying to create a pinhole collimater. So far, I have everything set up well, but the orientation is wrong with the preexisting orientation of the camera. (i.e. the primary axis of the pinhole should be the normal of the pixel grid) <br><br>The code I have now is:</div><div><br>## Volume at the front of the spect device for the collimator<br><br>/gate/front/daughters/name                                                 collimator<br>/gate/front/daughters/insert                                        box<br>/gate/collimator/geometry/setXLength            44. mm<br>/gate/collimator/geometry/setYLength            11.14 mm<br>/gate/collimator/geometry/setZLength            44. mm<br>/gate/collimator/placement/setTranslation       0. -0.2 0. mm<br>/gate/collimator/setMaterial                    Air<br><br># Square of tungsten with correct thickness at the wider base (crystal side) <br>/gate/collimator/daughters/name              base<br>/gate/collimator/daughters/insert            box<br>/gate/base/geometry/setXLength                            44. mm<br>/gate/base/geometry/setYLength                       1 mm<br>/gate/base/geometry/setZLength                          44. mm<br>/gate/base/placement/setTranslation            0. -0.2 0. mm<br>/gate/base/setMaterial Tungsten<br><br># Cone of tungsten for collimation<br>/gate/collimator/daughters/name        Tcone<br>/gate/collimator/daughters/insert      cone<br>/gate/Tcone/geometry/setRmin1              0 mm<br>/gate/Tcone/geometry/setRmax1                    3 mm<br>/gate/Tcone/geometry/setRmin2                    0 mm<br>/gate/Tcone/geometry/setRmax2                    25 mm<br>/gate/Tcone/geometry/setHeight                  11.14 mm<br>/gate/Tcone/placement/setTranslation       0. -0.2 0. mm<br>/gate/Tcone/setMaterial                               Tungsten<br><br># Cone of Air within the cone of tungsten<br>/gate/Tcone/daughters/name        hole2<br>/gate/Tcone/daughters/insert     cone<br>/gate/hole2/geometry/setRmin1         0 mm<br>/gate/hole2/geometry/setRmax1    2 mm<br>/gate/hole2/geometry/setRmin2    0 mm<br>/gate/hole2/geometry/setRmax2    24 mm<br>/gate/hole2/geometry/setHeight   11.14 mm<br>/gate/hole2/placement/setTranslation       0. -0.2 0. mm<br></div><div><br></div><div>So, basically, the hollow tungsten cone should be within the air volume allocate for the collimator. The primary axis of the cone is along the z direction though, so I get the following visualization:<br><br><div><img src="cid:ii_k0i4z4rx0" alt="image.png" width="322" height="253" style="margin-right: 0px;"><br>As you can see, the solid red cone (pinhole) is oriented along the z-axis, whereas the rest of the SPECT device is oriented along the y axis...<br><br>Things I've tried: <br>/gate/Tcone/placement/alignToY - This command just centers it along the y axis. Doesn't change the primary axis. <br>/gate/Tcone/placement/setRotationAxis + /gate/Tcone/placement/setRotationAngle - Also doesn't yield any helpful changes.<br><br>I'd appreciate any help! <br><br>Cheers!<br><br>Chris</div><br></div></div>