ARFoundation Camera Intrinsic Params

Hi,

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

 

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).

 

Can we calculate the camera intrinsic using existing APIs?

 

I'd also like to vote for this one!

 

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?

 

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.

 

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.

 

@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 ?

 

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.

 

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

 

I have been advised to chase this up in the Shader Graph forum but doubtful I will get any help as it's probably just the AR Foundation team who have any understanding of what the regular ARKitBackgroundShader does in AR Foundation not the general population of Shader Graph forums.

If anyone has had any experience with using ARCamera displayMatrix in shader graph, please let me know?

https://forum.unity.com/threads/how...on-in-shader-graph-displaymatrix-4x4.1094767/