prepareWithDevice

Declaration

var prepareWithDevice: ((any MTLDevice) -> Void)?

Mentioned in

• Applying core image filters as a postprocess effect
• Implementing postprocess effects using Metal compute functions

Discussion

If you assign a function to prepareWithDevice, RealityKit calls that function once, after it does its setup work, but before it renders the next frame. If you register a prepareWithDevice callback during app startup, RealityKit calls it before it renders the first frame. A callback function looks like this:

    func myPostProcessSetupCallback(device: MTLDevice) {
        // Handle setup work here.
    }

To register the function so RealityKit calls it, assign it to the prepareWithDevice property of the view’s renderCallbacks property.

arView.renderCallbacks.prepareWithDevice = myPostProcessSetupCallback

To remove the callback, assign nil.

arView.renderCallbacks.prepareWithDevice = nil

If you assign a new closure or function to the property after setting it to nil, RealityKit calls the new closure before it renders the next frame. In that case, avoid doing long-running tasks in the callback function to avoid rendering hitches.

See Also

Register callback closures

• postProcess