예제 #1
0
        public static HitTestRay HitTestRayFromScreenPos(this ARSCNView self, CGPoint point)
        {
            if (self.Session == null || ViewController.CurrentFrame == null)
            {
                return(null);
            }

            var frame = ViewController.CurrentFrame;

            if (frame == null || frame.Camera == null || frame.Camera.Transform == null)
            {
                return(null);
            }

            var cameraPos = SCNVector3Extensions.PositionFromTransform(frame.Camera.Transform);

            // Note: z: 1.0 will unproject() the screen position to the far clipping plane.
            var positionVec = new SCNVector3((float)point.X, (float)point.Y, 1.0f);
            var screenPosOnFarClippingPlane = self.UnprojectPoint(positionVec);

            var rayDirection = screenPosOnFarClippingPlane.Subtract(cameraPos);

            rayDirection.Normalize();

            return(new HitTestRay(cameraPos, rayDirection));
        }
예제 #2
0
        /// Reduce visual size change with distance by scaling up when close and down when far away.
        ///
        /// These adjustments result in a scale of 1.0x for a distance of 0.7 m or less
        /// (estimated distance when looking at a table), and a scale of 1.2x
        /// for a distance 1.5 m distance (estimated distance when looking at the floor).
        private float ScaleBasedOnDistance(ARCamera camera)
        {
            if (camera == null)
            {
                return(1.0f);
            }

            var distanceFromCamera = Position.Subtract(SCNVector3Extensions.PositionFromTransform(camera.Transform)).LengthFast;

            // This function reduces size changes of the focus square based on the distance by scaling it up if it far away,
            // and down if it is very close.
            // The values are adjusted such that scale will be 1 in 0.7 m distance (estimated distance when looking at a table),
            // and 1.2 in 1.5 m distance (estimated distance when looking at the floor).
            var newScale = (distanceFromCamera < 0.7f) ? (distanceFromCamera / 0.7f) : (0.25f * distanceFromCamera + 0.825f);

            return(newScale);
        }