overlaySKScene not rendered when using SCNRenderer - ios

Question

I'm using a SCNRenderer to render a scene into an existing OpenGL context (basically a modified version of the Vuforia ImageTarget sample) and the overlaySKScene to show annotations for the objects in the scene.
Since the update to iOS 9 the overlaySKScene is no longer rendered. None of the per frame actions (update:, didEvaluateActions, ...) are being called.
It worked with iOS 8 and the same SKScene still works with a SCNView in a different view controller in the same app.
Context setup:
self.context = [[EAGLContext alloc] initWithAPI:context.API sharegroup:scnViewContext.sharegroup];
OpenGL initialitaion (mostly copied from the Vuforia sample):
- (void)createFramebuffer
{
if (self.context) {
// Create default framebuffer object
glGenFramebuffers(1, &_defaultFramebuffer);
glBindFramebuffer(GL_FRAMEBUFFER, self.defaultFramebuffer);
// Create colour renderbuffer and allocate backing store
glGenRenderbuffers(1, &_colorRenderbuffer);
glBindRenderbuffer(GL_RENDERBUFFER, self.colorRenderbuffer);
// Allocate the renderbuffer's storage (shared with the drawable object)
[self.context renderbufferStorage:GL_RENDERBUFFER fromDrawable:(CAEAGLLayer*)self.layer];
GLint framebufferWidth;
GLint framebufferHeight;
glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_WIDTH, &framebufferWidth);
glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_HEIGHT, &framebufferHeight);
// Create the depth render buffer and allocate storage
glGenRenderbuffers(1, &_depthRenderbuffer);
glBindRenderbuffer(GL_RENDERBUFFER, self.depthRenderbuffer);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, framebufferWidth, framebufferHeight);
// Attach colour and depth render buffers to the frame buffer
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, self.colorRenderbuffer);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, self.depthRenderbuffer);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, self.stencilRenderbuffer);
// Leave the colour render buffer bound so future rendering operations will act on it
glBindRenderbuffer(GL_RENDERBUFFER, self.colorRenderbuffer);
}
}
- (void)setFramebuffer{
// The EAGLContext must be set for each thread that wishes to use it. Set
// it the first time this method is called (on the render thread)
if (self.context != [EAGLContext currentContext]) {
[EAGLContext setCurrentContext:self.context];
}
if (!self.defaultFramebuffer) {
// Perform on the main thread to ensure safe memory allocation for the
// shared buffer. Block until the operation is complete to prevent
// simultaneous access to the OpenGL context
[self performSelectorOnMainThread:#selector(createFramebuffer) withObject:self waitUntilDone:YES];
}
glBindFramebuffer(GL_FRAMEBUFFER, self.defaultFramebuffer);
}
- (BOOL)presentFramebuffer
{
// setFramebuffer must have been called before presentFramebuffer, therefore
// we know the context is valid and has been set for this (render) thread
// Bind the colour render buffer and present it
glBindRenderbuffer(GL_RENDERBUFFER, self.colorRenderbuffer);
return [self.context presentRenderbuffer:GL_RENDERBUFFER];
}
SCNRenderer setup:
self.skScene = [[MarkerOverlayScene alloc] initWithSize:CGSizeMake(2048, 2048)];
self.renderer = [SCNRenderer rendererWithContext:self.context options:nil];
self.renderer.autoenablesDefaultLighting = NO;
self.renderer.delegate = self;
self.renderer.overlaySKScene = self.skScene;
self.renderer.playing = YES;
if (self.sceneURL) {
self.renderer.scene = [SCNScene sceneWithURL:self.sceneURL options:nil error:nil];
[self.renderer prepareObjects:#[self.renderer.scene] withCompletionHandler:^(BOOL success) {
}];
}
Vuforia render callback:
- (void)renderFrameQCAR
{
[self setFramebuffer];
// Clear colour and depth buffers
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
// Render video background and retrieve tracking state
QCAR::State state = QCAR::Renderer::getInstance().begin();
QCAR::Renderer::getInstance().drawVideoBackground();
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);
glCullFace(GL_BACK);
if(QCAR::Renderer::getInstance().getVideoBackgroundConfig().mReflection == QCAR::VIDEO_BACKGROUND_REFLECTION_ON) {
glFrontFace(GL_CW); //Front camera
} else {
glFrontFace(GL_CCW); //Back camera
}
for (int i = 0; i < state.getNumTrackableResults(); ++i) {
// Get the trackable
const QCAR::TrackableResult* result = state.getTrackableResult(i);
QCAR::Matrix44F modelViewMatrix = QCAR::Tool::convertPose2GLMatrix(result->getPose());
SCNMatrix4 matrix = [self convertARMatrix:modelViewMatrix];
matrix = SCNMatrix4Mult(SCNMatrix4MakeRotation(M_PI_2, 1, 0, 0), matrix);
matrix = SCNMatrix4Mult(SCNMatrix4MakeScale(10, 10, 10), matrix);
self.arTransform = matrix;
}
if (state.getNumTrackableResults() == 0) {
self.arTransform = SCNMatrix4Identity;
}
[self.renderer renderAtTime:CFAbsoluteTimeGetCurrent() - self.startTime];
glDisable(GL_DEPTH_TEST);
glDisable(GL_CULL_FACE);
QCAR::Renderer::getInstance().end();
[self presentFramebuffer];
}

Answer 1

Mess with the skScene. settings. When I switched to ios9 no touches were getting through. I had to add skScene.userInteractionEnabled = NO; which was not needed in iOS8. I guess the defaults have changed or setting it to an overlay no longer changes the defaults.
Regardless, the issue is likely with the skScene settings.