internal (SCNVector3?, ARPlaneAnchor, Boolean) WorldPositionFromScreenPosition(CGPoint position, ARSCNView sceneView, SCNVector3?objectPos, bool infinitePlane = false)
{
var dragOnInfinitePlanesEnabled = AppSettings.DragOnInfinitePlanes;
// -------------------------------------------------------------------------------
// 1. Always do a hit test against exisiting plane anchors first.
// (If any such anchors exist & only within their extents.)
var planeHitTestResults = sceneView.HitTest(position, ARHitTestResultType.ExistingPlaneUsingExtent);
var result = planeHitTestResults.FirstOrDefault();
if (result != null)
{
var planeHitTestPosition = result.WorldTransform.Translation();
var planeAnchor = result.Anchor;
return(planeHitTestPosition, (ARPlaneAnchor)planeAnchor, true);
}
// -------------------------------------------------------------------------------
// 2. Collect more information about the environment by hit testing against
// the feature point cloud, but do not return the result yet.
SCNVector3?featureHitTestPosition = null;
var highQualityFeatureHitTestResult = false;
var highQualityfeatureHitTestResults = sceneView.HitTestWithFeatures(position, 18, 0.2, 2.0);
if (highQualityfeatureHitTestResults.Count() > 0)
{
var highQualityFeatureHit = highQualityfeatureHitTestResults.First();
featureHitTestPosition = highQualityFeatureHit.Position;
highQualityFeatureHitTestResult = true;
}
// -------------------------------------------------------------------------------
// 3. If desired or necessary (no good feature hit test result): Hit test
// against an infinite, horizontal plane (ignoring the real world).
if ((infinitePlane && dragOnInfinitePlanesEnabled) || !highQualityFeatureHitTestResult)
{
if (objectPos.HasValue)
{
var pointOnInfinitePlane = sceneView.HitTestWithInfiniteHorizontalPlane(position, objectPos.Value);
if (pointOnInfinitePlane != null)
{
return(pointOnInfinitePlane, null, true);
}
}
}
// -------------------------------------------------------------------------------
// 4. If available, return the result of the hit test against high quality
// features if the hit tests against infinite planes were skipped or no
// infinite plane was hit.
if (highQualityFeatureHitTestResult)
{
return(featureHitTestPosition, null, false);
}
// -------------------------------------------------------------------------------
// 5. As a last resort, perform a second, unfiltered hit test against features.
// If there are no features in the scene, the result returned here will be nil.
var unfilteredFeatureHitTestResults = sceneView.HitTestWithFeatures(position);
if (unfilteredFeatureHitTestResults.Count() > 0)
{
var unfilteredFeaturesResult = unfilteredFeatureHitTestResults.First();
return(unfilteredFeaturesResult.Position, null, false);
}
return(null, null, false);
}
public static (SCNVector3?, ARPlaneAnchor, bool) WorldPositionFromScreenPosition(CGPoint position,
ARSCNView sceneView,
SCNVector3?objectPos,
bool infinitePlane = false)
{
// -------------------------------------------------------------------------------
// 1. Always do a hit test against existing plane anchors first.
// (If any such anchors exist & only within their extents.)
var result = sceneView.HitTest(position, ARHitTestResultType.ExistingPlaneUsingExtent)?.FirstOrDefault();
if (result != null)
{
var planeHitTestPosition = result.WorldTransform.GetTranslation();
var planeAnchor = result.Anchor;
// Return immediately - this is the best possible outcome.
return(planeHitTestPosition, planeAnchor as ARPlaneAnchor, true);
}
// -------------------------------------------------------------------------------
// 2. Collect more information about the environment by hit testing against
// the feature point cloud, but do not return the result yet.
SCNVector3?featureHitTestPosition = null;
var highQualityFeatureHitTestResult = false;
var highQualityfeatureHitTestResults = sceneView.HitTestWithFeatures(position, 18f, 0.2f, 2f);
if (highQualityfeatureHitTestResults.Any())
{
featureHitTestPosition = highQualityfeatureHitTestResults[0].Position;
highQualityFeatureHitTestResult = true;
}
// -------------------------------------------------------------------------------
// 3. If desired or necessary (no good feature hit test result): Hit test
// against an infinite, horizontal plane (ignoring the real world).
if (infinitePlane || !highQualityFeatureHitTestResult)
{
if (objectPos.HasValue)
{
var pointOnInfinitePlane = sceneView.HitTestWithInfiniteHorizontalPlane(position, objectPos.Value);
if (pointOnInfinitePlane.HasValue)
{
return(pointOnInfinitePlane, null, true);
}
}
}
// -------------------------------------------------------------------------------
// 4. If available, return the result of the hit test against high quality
// features if the hit tests against infinite planes were skipped or no
// infinite plane was hit.
if (highQualityFeatureHitTestResult)
{
return(featureHitTestPosition, null, false);
}
// -------------------------------------------------------------------------------
// 5. As a last resort, perform a second, unfiltered hit test against features.
// If there are no features in the scene, the result returned here will be nil.
var unfilteredFeatureHitTestResults = sceneView.HitTestWithFeatures(position);
if (unfilteredFeatureHitTestResults.Any())
{
var first = unfilteredFeatureHitTestResults[0];
return(first.Position, null, false);
}
return(null, null, false);
}
