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ARFoundation Camera Intrinsic Params

Discussion in 'AR' started by ibrahimpenekli, Dec 25, 2018.

  1. ibrahimpenekli

    ibrahimpenekli

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    Mar 10, 2015
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    Hi,

    Is there a way to get camera intrinsic parameters via ARFoundation interface? (Focal length and principal point etc)
     
  2. tdmowrer

    tdmowrer

    Unity Technologies

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    Not currently, but there will be in the next release.
     
  3. EdwinLyons

    EdwinLyons

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    Oct 4, 2012
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    Just like to vote for this feature - it used to be possible to get this when using the ARKit Unity plugin, but it appears to have been removed in recent releases, so I'm now left with no way to do this (without patching the ARKit plugin myself to add it back in).
     
  4. ecr23

    ecr23

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    Can we calculate the camera intrinsic using existing APIs?
     
  5. camogram

    camogram

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    Jul 11, 2018
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    I'd also like to vote for this one!
     
  6. tdmowrer

    tdmowrer

    Unity Technologies

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  7. HyperLethalVector92

    HyperLethalVector92

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    Hi, I've managed to pull the camera image, however the 'TryGetIntrinsics' Method always returns false, is there something special I should be doing for the build to be able to do this?
     
  8. avilleret

    avilleret

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    how is it possible to retrieve the intrinsic parameter of the new iPad depth camera ? it is available through Apple ARKit but I can't find it in the ARFoundation 4.01-preview7 documentation.
     
  9. tdmowrer

    tdmowrer

    Unity Technologies

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    It is not currently exposed, but you can get a pointer to the ARFrame and access it from there if you're wiling to write a bit of Objective-C. See https://docs.unity3d.com/Packages/com.unity.xr.arfoundation@4.1/manual/extensions.html and https://docs.unity3d.com/Packages/c...ngine_XR_ARSubsystems_XRCameraFrame_nativePtr
     
  10. avilleret

    avilleret

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    Thanks for the hint regarding direct Lidar access.
    However, how to be sure that the intrinsics parameter we get with `TryGetIntrinsics` are related to the frame we get with `TryGetLatestImage` ?
    Since the intrinsics parameters could change from frame to frame due to autofocus, we need some timestamp to associate intrinsic parameter and the corresponding frame.
     
  11. thibautvdumont

    thibautvdumont

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    Oct 6, 2015
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    @tdmowrer

    I'd also be interested to know if the intrinsics we get from TryGetIntrinsics are related to the raw and unprocessed cpu image we get with TryGetLatestImage.

    More precisely, the image I get with TryGetLatestImage on my iphone is mirrored, so I have to apply XRCpuImage.Transformation.MirrorY when converting it :
    Code (CSharp):
    1.         var requestParams = new XRCpuImage.ConversionParams
    2.         {
    3.             outputFormat = TextureFormat.RGB24,
    4.             inputRect = new RectInt(0, 0, img.width, img.height),
    5.             outputDimensions = new Vector2Int(img.width, img.height),
    6.             transformation = XRCpuImage.Transformation.MirrorY
    7.         };
    Should I correct the optical center on X accordingly in the provided intrinsic matrix so that Ox = cpu_image_width - Ox ?
     
    Last edited: Jan 8, 2021
  12. KirillKuzyk

    KirillKuzyk

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    Nov 4, 2013
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    I think what you're looking for is displayMatrix. ARKit and ARCore use it to display the camera image in correct orientation/crop.
    Here is a link that describes the anatomy of the displayMatrix.
     
    thibautvdumont likes this.
  13. thibautvdumont

    thibautvdumont

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    Many thanks, I was about to decompose the displayMatrix to get the corrections I should apply on the intrinsic, so this is definitely useful :)
     
  14. ROBYER1

    ROBYER1

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