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Extrinsic transformation between Hololens 'origin' and locatable RGB camera?
Hi,
For a project of mine, I am needing to know the precise rotation and translation between the HoloLens' locatable camera and the 'origin' point of the HoloLens device (i.e. the location in Unity where the virtual Main Camera is). I can use the PhotoCameraFrame class to get the transform between the locatable camera and the world-space origin of the spatial mesh, but this doesn't give me the transform between the camera and the HoloLens origin.
I have already tried placing the HoloLens in a fixed location and querying both the locatable-camera-to-world and the HoloLens-origin-to-world matrices, but because these queries are not synchronized and there is small variation over time in the estimation of these matrices, I am getting small changes in the locatable-camera-to-HoloLens-origin matrix.
This is info that I would think should be directly accessible in some documentation. Does anyone know where I could find it?
Best Answer
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utekai ✭✭✭
See https://forums.hololens.com/discussion/782/live-stream-of-locatable-camera-webcam-in-unity
Discussion about minor differences due to the two slightly different coordinate systems.
Also see method calls in https://docs.unity3d.com/550/Documentation/ScriptReference/VR.WSA.WebCam.PhotoCaptureFrame.html
5
Answers
Have you gone over this documentation? https://developer.microsoft.com/en-us/windows/holographic/locatable_camera
Yes, I have looked through that, but I was unable to find what I was looking for. That page talks about going between the CameraCoordinateSystem (the coordinate system of the locatable camera) and the application/world coordinate system, but nothing about the coordinate system of the headset itself (i.e. the Main Camera position in Unity). Is there a way to specify at runtime what the application coordinate system I care about is?
See https://forums.hololens.com/discussion/782/live-stream-of-locatable-camera-webcam-in-unity
Discussion about minor differences due to the two slightly different coordinate systems.
Also see method calls in https://docs.unity3d.com/550/Documentation/ScriptReference/VR.WSA.WebCam.PhotoCaptureFrame.html