VTK/WASM: Push client camera state to server (i.e. update server camera to match the client camera)

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@jaswantp Hi Jaswant, I know we spoke about this earlier but I forgot to ask specifically how it’s done.

In VTK/WASM, the active camera on the server does not stay synchronized with the active camera on the frontend unless you manually send some kind of “synchronize” command to the server from the frontend.

For example, let’s say I have moved, zoomed, and rotated the camera a bit on the frontend, and upon clicking a button, I wish to send this new camera state to the server, so that the server’s vtkCamera object is in exactly the same position, zoom, and orientation. What exactly do I call in JavaScript to make this happen?

I have experimented with the following but it’s not working for me. I’m not getting an error; it just doesn’t do anything to to the server’s camera:

function updateServerCamera(){

    // wasmManager is a VtkWASMHandler object from the outer scope

    // renderWindowWasmId is a number from the outer scope

    const [clientCameraId] = wasmManager.cameraIds;

    const clientCameraState = wasmManager.getState(clientCameraId);

    await wasmManager.patchState(clientCameraState); // this did not work

    await wasmManager.update(renderWindowWasmId); // this did not work

}

As you can see, wasmManager.patchState() and wasmManager.update() did not work.

Is there a method I haven’t tried yet?

I also found these methods and tried them, but to no avail:

sceneManager.updateStateFromObject(firstCameraId)

sceneManager.updateObjectFromState(JSON.stringify(cameraState))

2

You need to send that state to the server yourself, and then ask the objectManager to update VTK from the given state. wasmManager does not handle any networking.

I’ve found an example here