How to synchronize camera ?

[lchauvin]

Hello,

I would like to be able to synchronize cameras for all images (when I zoom on one image, and switch to another image, to get the same view).
I was able to do this with a previous version of VolView, but lots have changed since then.

I initially put a flag in CameraConfig to check if cameras should be sync or not, and then when a camera property was updated, I was checking the flag and updating all cameras with the same properties.

However, I don't think it works since I updated VolView, because it seems to sync CameraConfig with vtkCamera in usePersistentCameraConfig.ts, and vtkCamera doesn't have the flag I added, so it raised some error.

Could you suggest a way to do achieve this ?

Thank you.

[lchauvin]

I managed to synchronize camera properties, but when I change image, it resets the camera

[lchauvin]

Where would be the best place to put the logic for syncing cameras ? usePersistCameraConfig.ts ?

[lchauvin]

It seems from this code:

type KeyType = keyof CameraConfig;
  const keys: KeyType[] = [
    'position',
    'focalPoint',
    'viewUp',
    'parallelScale',
    'directionOfProjection',
  ];

  const cameraRefs = keys.reduce(
    (refs, key) => ({
      ...refs,
      [key]: guardedWritableRef(
        vtkFieldRef(camera, key),
        (incoming) => !!incoming
      ),
    }),
    {} as Record<KeyType, Ref<any>>
  );

that CameraConfig can only have properties that are in vtkCamera. What if I want to add a config parameter that is not in vtkCamera ?

How would I do that ?

[lchauvin]

What if I want to add something on the Pinia store that will not be set in VTK.js camera ? Because it seems both are using CameraConfig

[PaulHax]

Should be safe to remove all explcit reference to CameraConfig in usePersistCameraConfig.ts

[lchauvin]

I got this to work.

However, the issue I have now, is that, when I change image, it resets the camera.

I tried to comment out the resetCamera function in SliceViewer but it doesn't work.

I think it might have something to do with disableAutoResetCamera but I'm not sure. I tried to turn it off, but then the image is all black (or not in the FOV, not sure).

[PaulHax]

progress! ⭐️

Not sure. Are we re-creating the VTK.js scene/camera on switching images? Are you saving the camera pose then applying after loading the matching image?

Perhaps time to open a PR and disscuss with code.

[lchauvin]

I created a PR here: #615