I am looking for help figuring out how to approach this problem. SceneKit allows you to set a CALayer as the contents of a SCNNode's appearance. Is it possible to get the CALayer from a UIWebView and render it as the contents of an SCNMaterial?
I am attempting to change the SCNNode's diffuse contents to the WebView Layer in the function - (void)webViewDidFinishLoad:(UIWebView *)webView completes, but the code crashes.
But I get this error: 43282] bool _WebTryThreadLock(bool), 0x7fae33f33680: Tried to obtain the web lock from a thread other than the main thread or the web thread. This may be a result of calling to UIKit from a secondary thread. Crashing now...
Here is my code for reference
//
// GameViewController.h
// WebViewLayerTest
//
#import <UIKit/UIKit.h>
#import <SceneKit/SceneKit.h>
@interface GameViewController : UIViewController <UIWebViewDelegate,SCNNodeRendererDelegate>
@property (nonatomic, retain) IBOutlet UIWebView *webView;
@property (nonatomic,retain) SCNBox *box;
-(void) storeLayer;
@end
//
// GameViewController.m
// WebViewLayerTest
//
//
#import "GameViewController.h"
#import <QuartzCore/QuartzCore.h>
@implementation GameViewController
- (void)viewDidLoad
{
[super viewDidLoad];
self.webView = [[UIWebView alloc] initWithFrame:CGRectMake(10, 10, self.view.bounds.size.width-20.0, self.view.bounds.size.height-30.0)];
NSString *urlAddress = @"https://www.google.com/";
NSURL *url = [NSURL URLWithString:urlAddress];
NSURLRequest *requestObj = [NSURLRequest requestWithURL:url];
[self.webView loadRequest:requestObj];
self.webView.delegate = self;
// create a new scene
SCNScene *scene = [SCNScene scene];
// create and add a camera to the scene
SCNNode *cameraNode = [SCNNode node];
cameraNode.camera = [SCNCamera camera];
[scene.rootNode addChildNode:cameraNode];
// // place the camera
cameraNode.position = SCNVector3Make(0, 0, 15);
// create and add a light to the scene
SCNNode *lightNode = [SCNNode node];
lightNode.light = [SCNLight light];
lightNode.light.type = SCNLightTypeOmni;
lightNode.position = SCNVector3Make(0, 10, 10);
[scene.rootNode addChildNode:lightNode];
// create and add an ambient light to the scene
SCNNode *ambientLightNode = [SCNNode node];
ambientLightNode.light = [SCNLight light];
ambientLightNode.light.type = SCNLightTypeAmbient;
ambientLightNode.light.color = [UIColor darkGrayColor];
[scene.rootNode addChildNode:ambientLightNode];
self.box = [SCNBox boxWithWidth:1.0 height:1.0 length:1.0 chamferRadius:0.05];
self.box.firstMaterial.diffuse.contents = [UIColor blueColor];
SCNNode* ship = [SCNNode nodeWithGeometry:self.box];
// // animate the 3d object
[ship runAction:[SCNAction repeatActionForever:[SCNAction rotateByX:0 y:2 z:0 duration:1]]];
//
// // retrieve the SCNView
SCNView *scnView = (SCNView *)self.view;
//
[scene.rootNode addChildNode:ship];
// // set the scene to the view
scnView.scene = scene;
// allows the user to manipulate the camera
scnView.allowsCameraControl = YES;
// show statistics such as fps and timing information
scnView.showsStatistics = YES;
// configure the view
scnView.backgroundColor = [UIColor blackColor];
// add a tap gesture recognizer
// UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)];
// NSMutableArray *gestureRecognizers = [NSMutableArray array];
// [gestureRecognizers addObject:tapGesture];
// [gestureRecognizers addObjectsFromArray:scnView.gestureRecognizers];
// scnView.gestureRecognizers = gestureRecognizers;
}
- (void) handleTap:(UIGestureRecognizer*)gestureRecognize
{
// retrieve the SCNView
SCNView *scnView = (SCNView *)self.view;
// check what nodes are tapped
CGPoint p = [gestureRecognize locationInView:scnView];
NSArray *hitResults = [scnView hitTest:p options:nil];
// check that we clicked on at least one object
if([hitResults count] > 0){
// retrieved the first clicked object
SCNHitTestResult *result = [hitResults objectAtIndex:0];
// get its material
SCNMaterial *material = result.node.geometry.firstMaterial;
// highlight it
[SCNTransaction begin];
[SCNTransaction setAnimationDuration:0.5];
// on completion - unhighlight
[SCNTransaction setCompletionBlock:^{
[SCNTransaction begin];
[SCNTransaction setAnimationDuration:0.5];
material.emission.contents = [UIColor blackColor];
[SCNTransaction commit];
}];
material.emission.contents = [UIColor redColor];
[SCNTransaction commit];
}
}
- (void)webViewDidFinishLoad:(UIWebView *)webView {
NSLog(@"Finished Loading");
// self.box.firstMaterial.diffuse.contents = _webView.layer;
dispatch_async(dispatch_get_main_queue(),^ {
self.box.firstMaterial.diffuse.contents = _webView.layer;
} );
// [self performSelectorOnMainThread:@selector(storeLayer) withObject:nil waitUntilDone:YES];
}
-(void) storeLayer{
self.box.firstMaterial.diffuse.contents = _webView.layer;
}
- (BOOL)shouldAutorotate
{
return YES;
}
- (BOOL)prefersStatusBarHidden {
return YES;
}
- (UIInterfaceOrientationMask)supportedInterfaceOrientations
{
if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
return UIInterfaceOrientationMaskAllButUpsideDown;
} else {
return UIInterfaceOrientationMaskAll;
}
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
@endI encountered the same problem and I solved by the following methods.
1. Experiments found that CALayer can be used directly to set diffuse.contents，but UIView can not
func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
guard let imageAnchor = anchor as? ARImageAnchor else { return }
let testLayer = CALayer()
testLayer.frame = self.view.bounds
testLayer.backgroundColor = UIColor.blue.cgColor
let referenceImage = imageAnchor.referenceImage
let plane = SCNPlane(width: referenceImage.physicalSize.width,
height: referenceImage.physicalSize.height)
plane.firstMaterial?.diffuse.contents = testLayer
let planeNode = SCNNode(geometry: plane)
planeNode.eulerAngles.x = -.pi / 2
node.addChildNode(planeNode)
}
}
2. Get a webview snapshot when the webview did finish load.
func captureWebview() -> UIImage{
var image : UIImage!
UIGraphicsBeginImageContextWithOptions(webView.scrollView.contentSize, webView.scrollView.isOpaque, 0.0)
let savedContentOffset = webView.scrollView.contentOffset
let savedFrame = webView.scrollView.frame
webView.scrollView.contentOffset = CGPoint.zero
webView.scrollView.frame = CGRect(x: 0, y: 0, width: webView.scrollView.contentSize.width,height: webView.scrollView.contentSize.height)
webView.scrollView.layer.render(in: UIGraphicsGetCurrentContext()!)
image = UIGraphicsGetImageFromCurrentImageContext()
webView.scrollView.contentOffset = savedContentOffset
webView.scrollView.frame = savedFrame
UIGraphicsEndImageContext()
return image
}
3. Set the webview snapshot as diffuse.contents
func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
guard let imageAnchor = anchor as? ARImageAnchor else { return }
let referenceImage = imageAnchor.referenceImage
let plane = SCNPlane(width: referenceImage.physicalSize.width,
height: referenceImage.physicalSize.height)
plane.firstMaterial?.diffuse.contents = self.testImage
let planeNode = SCNNode(geometry: plane)
planeNode.eulerAngles.x = -.pi / 2
node.addChildNode(planeNode)
}