I noticed that even when forward projecting a perfectly axially symmetric image using a BlocksOnCylindrical scanner geometry, the resulting viewgrams are not axially symmetric:
This turned out to be a combination of a bug in GeometryBlocksOnCylindrical.cxx and in the downsampling of the scanners in scatter simulation and in the interpolation tests. After fixing, it looks like this:
I noticed that even when forward projecting a perfectly axially symmetric image using a BlocksOnCylindrical scanner geometry, the resulting viewgrams are not axially symmetric:
This turned out to be a combination of a bug in GeometryBlocksOnCylindrical.cxx and in the downsampling of the scanners in scatter simulation and in the interpolation tests. After fixing, it looks like this: