In the following screenshot of some simulation in HepRApp Data Browser, are the x (red), y (green), z (blue) axes in front of the simulated beam or behind it? If it is in front, then it is a left handed Cartesian coordinates, if it is behind, then it is a right handed Cartesian coordinates. It’s funny that a wireframe view allows you to imagine it in both ways.
I’m not familiar with HepRApp, but the Geant4 axes are right-handed. I can personally vouch for that. I believe HepRApp simply draws what it is asked to draw, namely coloured tubes with a cone at one end.
The axes are (x,y,z) → (red, green, blue). (There should be labels on them - maybe HepRApp doesn’t do text?)
Is there a perspective option in HepRApp? That might help.
By the way, I’m pleased to see HepRApp being used.
thanks for confirming the right-handedness of the coordinate system in Geant4.
HepRApp Browser doesn’t do text. But that’s Ok. We all know that RGB means xyz.
There are quite some projection choices, including perspective, in HepRApp. None of them helps to break the ambiguity due to the lack of shadowing in wireframe, that is, there is no way to tell which line is in front, which is behind.
I like HepRApp Browser a lot. It has some nice feature for geometry debugging. But It’s hard to make it work in a modern system due to its dependence on an old version of java. I created a docker image to run HepRApp, https://hub.docker.com/r/physino/heprapp. This way, I can run it in any system that can handle docker.
Can someone confirm my understanding of beam view and side view?
