Figuring out if Anchor is visible in current screen

Question

I'm using ARCore to build my android app, where I allowing users to place anchors. I need to be able to check if the Anchor is in the current frame. Any idea how can I do it? Thanks!

Answer 1

I created a method based on camera.worldToScreenPoint(worldPosition). So I can check if a position is visible:

fun com.google.ar.sceneform.Camera.isWorldPositionVisible(worldPosition: Vector3): Boolean {
    val var2 = com.google.ar.sceneform.math.Matrix()
    com.google.ar.sceneform.math.Matrix.multiply(projectionMatrix, viewMatrix, var2)
    val var5: Float = worldPosition.x
    val var6: Float = worldPosition.y
    val var7: Float = worldPosition.z
    val var8 = var5 * var2.data[3] + var6 * var2.data[7] + var7 * var2.data[11] + 1.0f * var2.data[15]
    if (var8 < 0f) {
        return false
    }
    val var9 = Vector3()
    var9.x = var5 * var2.data[0] + var6 * var2.data[4] + var7 * var2.data[8] + 1.0f * var2.data[12]
    var9.x = var9.x / var8
    if (var9.x !in -1f..1f) {
        return false
    }

    var9.y = var5 * var2.data[1] + var6 * var2.data[5] + var7 * var2.data[9] + 1.0f * var2.data[13]
    var9.y = var9.y / var8
    return var9.y in -1f..1f
}

(And I fixed the problem that Anton Stukov said in the comments)