I am using USRBIN to score energy deposition of a cylindrical structure and get three plots as the following（projections on R,Φ,Z respectively）：
But I’m a little confused about the beginer course which said:
Take Z projection for example, does it mean that the value shown in the plot is the average value over Z axis ( here z from -2 to 28 )?
As I am more interested in the space distribution of energy deposition, is there a way to get 3D plots?
Your interpretation is correct: e.g. in the z-projection, the values are the average along the z axis (here along the full length of your object). However, you can set specific limits for the coordinates in the Plot menu (Look for the “Projection and Limits” box), so you could generate the same plot taking only a slice along z, alowing you to scan different depths of the object.
To get a 3D view, you can create a layer in the Geoeditor adding the specific URSBIN scoring to a 3D view of the geometry. This would then plot the results on top of your geometry. See for example slide 21 in this lecture from the recent online course: https://indico.cern.ch/event/955105/contributions/4013349/attachments/2108473/3546267/08_Scoring_I_2020_online.pdf