Hi everyone, trying to display only secondary particles almost works quite nicely with /vis/filtering/trajectories/create/attributeFilter secondaries /vis/filtering/trajectories/secondaries/setAttribute PID /vis/filtering/trajectories/secondaries/addValue 0 /vis/filtering/trajectories/secondaries/…

Mmmm. All trajectories NOT with Parent ID PID == 0. Not sure what you mean, “gamma particles that are only redirected”. OK, I see what you mean - for example, from a Compton scatter. [image] weller: Is there a way to display all particles starting from the point of first physical interaction, …

great idea, thanks! I tried your suggestion and report: it partially works. I can estimate the time the photons require to travel to the first surface, and indeed with the right startTime, only the remaining part of the tracks is drawn. However, being a single global value for all tracks, this doe…

OK. Yes. That’s right. No single start time for all events. Mmmm. One last idea. In principle (be warned, I have never tried this), you can add your own attributes to a trajectory. This means implementing you own trajectory class, G4MyTrajectory and G4MyTrajectoryPoint, ultimately inherited from G…

Interesting idea, but I‘m afraid that is beyond my skill level. Thanks for your suggestions, though! Wondering if this would actually work… as I understand, the trajectory is the whole „path“ the gamma takes, from primary event until it completely vanishes. The scattering events are points where ad…

I have just realised a rich trajectory offers a whole slew of attributes. Would these do? Process Defined Step (PDS): G4String Process Type Defined Step (PTDS): G4String Trying to think how to dump values. Try /vis/viewer/set/picking and pick a relevant trajectory. Printed at startup: G4Tr…

in principle yes, but the original challenge remains: after scattering it is still the same track/trajectory. So filtering trajectories does either remove the photon for good, or not at all. I see now that the track has a list of G4RichTrajectoryPoints. Filtering for Pre-step-point global time (Pr…

Ah! OK. So sorry, nothing available on the command line. Another idea, which only works in sequential mode (export G4RUN_MANAGER_TYPE=Serial). Draw your own trajectories. In end of event action: auto TC = event -> GetTrajectoryContainer (); if (!TC) return; auto pVVisManager = G4VVisManager:…

Mmmm. Maybe. But not my area of expertise. :thinking:

Dear experts, the topic came up again in a different variant: I would like to count photons with a sensitive detector, and distinguish between non-interacting photons directly from the primary vertex and photons that were redirected via Rayleigh or Compton events. Unfortunately, here the same hol…

Filter primary particles

Recording, Visualizing and Persisting Data

weller January 21, 2021, 4:38pm 9

are there specific reasons to maintain the incident photon in compton / rayleigh interactions? could it be replaced by a secondary? maybe that is a much more trivial change to the code than custom display routines…