[Gate-users] SPECT projection plane and output world coordinates of detector pixel elements

[Changguo Ji]

Dear Gaters,
I am trying to run the example_SPECT …. I have generated the projection image 
which is the interfile format. I used the continuous crystal material.
 My questions are: 
1)      What's the exact plane location used to calculate this projection image? 
i.e. the projection plane is the plane right after the crystal or the middle 
plane of crystal? I want use this projection image to verify a reconstruction 
algorithm, thus accurate geometrical information for pixel plane is crucial.
2) How to modify the source code to calculate and generate world coordinates of 
detector pixel elements?
Any experts can clarify it or give me some instructions will be greatly helpful!
Thanks a lot!
Jason