Questions on how to use the OptiX Engine

I am rusty on object oriented Programming and i have some questions which i suppose will be easy to answer for you.

  1. I would like to add a variable „relativeSpeedInXDirection“ to my GeometryInstances in order to
    calculate Doppler shifts, how and where do i do that?
  2. I would like to add a variable „dopplerShift“ to the payload of each Ray
  3. I would like to change the position of my light along with the position of the camera,
    While I have managed to do this, I do not know how to access the lightposition of the light-Struct
    within the light_buffer of the tutorial file and change the position directly
    (what I do is use a variable instead)
  4. I do not know how to save the output_buffer in a matlab_friendly way

Any help would be greatly appreciated!
Mike

PS: Is there a Tutorial which teaches me how to use the OptiX framework?
(Learn me how to fish, rather than fish for me)