Add image overlays

    // Create an Envelope for displaying the image frame in the correct location.
    private val pacificSouthwestEnvelope = Envelope(
        center = pointForImageFrame,
        width = 15.0958,
        height = -14.3770
    )

    // (untransformed) Lower-left -> Upper-left -> Upper-right -> Lower-right
    private val pacificSouthwestPolygon = Polygon(
        listOf(
            Point(x = -123.000, y = 27.000),
            Point(x = -123.000, y = 40.000),
            Point(x = -120.000, y = 40.000),
            Point(x = -120.000, y = 27.000),
        )
    )

            // Create an image with the given path and use it to create an image frame

            val imageFrame = ImageFrame(
                uri = imageFile.path,
                extent = pacificSouthwestEnvelope
            )

                val imageFrame = ImageFrame.createWithImageAndExtent(
                    image = bitmapDrawable,
                    extent = pacificSouthwestEnvelope
                )

        var imageOverlay = ImageOverlay()

        // Attach the initial image frame to the image overlay.
        imageOverlay.imageFrame = imageFrames[0]
        imageOverlay.opacity = 0.5f

                // Add image overlay to scene view's image overlays
                SceneView(
                    modifier = Modifier
                        .fillMaxSize(),
                    arcGISScene = scene,
                    imageOverlays = listOf(imageOverlay)
                )

        scene.initialViewpoint = imageFrames[0].extent?.let { extent ->
            Viewpoint(
                boundingGeometry = extent,
                camera = camera
            )
        }

        // Get the image files from local storage and iterate over the files.
        // For each file, create an image frame, and add it to imageFrames list.
        (File(filePath).listFiles())?.sorted()?.forEach { imageFile ->

            // Create an image with the given path and use it to create an image frame

            val imageFrame = ImageFrame(
                uri = imageFile.path,
                extent = pacificSouthwestEnvelope
            )

            imageFrames.add(imageFrame)

        }

        // Get the current period from the fps state flow
        val period = when (_fps.value) {
            60 -> 17 // 1000ms/17 = 60 fps
            30 -> 33 // 1000ms/33 = 30 fps
            15 -> 67 // 1000ms/67 = 15 fps
            else -> 0
        }
        // Cancel any timers that might be running
        timer?.cancel()
        timer = null
        // Create a new timer with the given period
        timer = kotlin.concurrent.fixedRateTimer("Image overlay timer", period = period.toLong()) {
            addNextImageFrameToImageOverlay()
        }

    private var imageFrameIndex = 0

    private fun addNextImageFrameToImageOverlay() {
        // Set image frame to image overlay
        imageOverlay.imageFrame = imageFrames[imageFrameIndex]
        // Increment the index to keep track of which image to load next
        imageFrameIndex++
        // Reset index once all files have been loaded
        if (imageFrameIndex == imageFrames.size)
            imageFrameIndex = 0
    }