Help reading transformation coordinates from a json file

[shefmarkh]

Hello,

I am trying to read a cylinder surface in from a json file. This seems to work in that I can create a cylinder surface and verify it has the dimensions of those in the json file. The problem I have is that I also have a transformation x,y,z stored in the file and when I go onto create a volume, using the surface, I am unable to take this into account.

I create a "nominal" cylinder here:

https://github.com/shefmarkh/acts/blob/pflowSurfaces/Tests/UnitTests/Core/Detector/PFlowSurfaces.cpp#L82

using the transform identity. ReadRadius etc are defined from the surface:

https://github.com/shefmarkh/acts/blob/pflowSurfaces/Tests/UnitTests/Core/Detector/PFlowSurfaces.cpp#L60

The test json file I have is attached, which is where the surface has been read from.

PFlowSurfaces.json

The next thing I tried is to create a volume using the transform read from the json file:

https://github.com/shefmarkh/acts/blob/pflowSurfaces/Tests/UnitTests/Core/Detector/PFlowSurfaces.cpp#L109

which does not show any shift in coordinates of the cylinder (the transform is a linear shift in Z)
, so I presume the transform has not been taking into account.

I tested that the transform I read in has coordinates 0,0,0 rather than the values stored:

https://github.com/shefmarkh/acts/blob/pflowSurfaces/Tests/UnitTests/Core/Detector/PFlowSurfaces.cpp#L102

so I suppose this is where I am going wrong. The transform was read as shown here:

https://github.com/shefmarkh/acts/blob/pflowSurfaces/Tests/UnitTests/Core/Detector/PFlowSurfaces.cpp#L44

( I also tried using the key "transform" initially, which had the same result).

Is it obvious to anyone where I am going wrong?

Thanks,

Mark