ARKit plane visualization - arkit

Question

I want to be able to visualize the planes that my ARKit app detects. How do I do that?
This is what I want to be able to do

Answer 1

Create a new AR project in Xcode with SceneKit and Obj-C, then add these to ViewController.m:
//as a class or global variable:
NSMapTable *planes;
//add to viewWillAppear:
configuration.planeDetection = ARPlaneDetectionHorizontal;
//to viewDidLoad:
planes = [NSMapTable mapTableWithKeyOptions:NSMapTableStrongMemory
valueOptions:NSMapTableWeakMemory];
//new functions:
- (void)renderer:(id<SCNSceneRenderer>)renderer didAddNode:(SCNNode *)node forAnchor:(ARAnchor *)anchor {
if( [anchor isKindOfClass:[ARPlaneAnchor class]] ){
[planes setObject:anchor forKey:node];
ARPlaneAnchor *pa = anchor;
SCNNode *pn = [SCNNode node];
[node addChildNode:pn];
pn.geometry = [SCNPlane planeWithWidth:pa.extent.x height:pa.extent.z];
SCNMaterial *m = [SCNMaterial material];
m.emission.contents = UIColor.blueColor;
m.transparency = 0.1;
pn.geometry.materials = #[m];
pn.position = SCNVector3Make(pa.center.x, -0.002, pa.center.z);
pn.transform = SCNMatrix4MakeRotation(-M_PI / 2.0, 1, 0, 0);
}
}
- (void)renderer:(id<SCNSceneRenderer>)renderer didUpdateNode:(SCNNode *)node forAnchor:(ARAnchor *)anchor {
if( [anchor isKindOfClass:[ARPlaneAnchor class]] ){
[planes setObject:anchor forKey:node];
ARPlaneAnchor *pa = anchor;
SCNNode *pn = [node childNodes][0];
SCNPlane *pg = pn.geometry;
pg.width = pa.extent.x;
pg.height = pa.extent.z;
pn.position = SCNVector3Make(pa.center.x, -0.002, pa.center.z);
}
}
- (void)renderer:(id<SCNSceneRenderer>)renderer didRemoveNode:(nonnull SCNNode *)node forAnchor:(nonnull ARAnchor *)anchor{
[planes removeObjectForKey:node];
}
You'll see translucent planes, give m.emission.contents a texture if you feel so.
Alternatively get the Example App from Apple in Swift