I want to project the geometric model in G4 onto a plane (plane x-y, plane x-z, plane y-z) and draw it with MATLAB, but how do I get the coordinates of the projection points projected onto the plane?

I assume that by (*plane x-y, plane x-z, plane y-z*) you mean the coordinate planes.

The coordinate planes are described by the following equations:

*plane x-y: z = 0*

*plane x-z: y = 0*

*plane y-z: x = 0*

The projections of a point (*x,y,z*) onto the coordinate planes will have the following coordinates:

*on plane x-y: (x,y,0)*

*on plane x-z: (x,0,z)*

*on plane y-z: (0,y,z)*

Thanks so much for your answer!

Now the question is how do I get the projected coordinates of the geometric outline without using the mathematical method.

I wonder if it is possible to directly obtain the projection coordinate information of geometry (such as cube, cylinder, etc.) from GEANT4, for example, from DAWN or VRML output file

You will see all the coordinates in a VRML file:

/vis/open VRML2FILE

/vis/viewer/flush

Similarly DAWNFILE.