SceneKit – Playing DAE and USDZ animation using Objective-C - objective-c

Question

I want to create walking man animation in SceneKit.
I'm exporting animated .dae files from 3DSMax + OpenCollada , I also use ConvertToXcodeCollada to combine all animations in one.
How i get animation:
SCNScene *humanScene = [SCNScene sceneNamed:#"art.scnassets/myScene.DAE"];
CAAnimation *Animation = [[humanScene rootNode] animationForKey:#"myScene-1"];
I also try to get animation from "SCNSceneSource"
How i add animation:
SCNNode *humanNode = [humanScene.rootNode childNodeWithName:#"myScene-1" recursively:YES];
[humanNode addAnimation:walkingAnimation forKey:#"myScene-1"];
or:
SCNNode* humanNode = [SCNNode new];
for(SCNNode* node in humanScene.rootNode.childNodes){
[humanNode addChildNode:node];
}
[humanNode addAnimation:walkingAnimation forKey:#"myScene-1"];
My object "walkingAnimation" is "CAAnimationGroup".
But it doesn't animate in application.
I can see animation only in Xcode sceneKit editor.
example of my .DAE file

Answer 1

Try the following code with your model. It works. I used Xcode 13.2.1 in macOS 12.1.
At first fill viewDidLoad method:
#import "GameViewController.h"
#implementation GameViewController
SCNView *sceneView;
bool notRunningSwitch;
NSMutableDictionary<NSString*, CAAnimation*> *animations;
SCNNode *node;
- (void)viewDidLoad
{
[super viewDidLoad];
sceneView = (SCNView *)self.view;
notRunningSwitch = YES;
animations = #{}.mutableCopy;
node = [SCNNode node];
SCNScene *scene = [SCNScene scene];
sceneView.scene = scene;
sceneView.autoenablesDefaultLighting = YES;
sceneView.allowsCameraControl = YES;
[self anime];
}
Then anime and loadAnime methods:
- (void)anime
{
SCNScene *standStillScene = [SCNScene sceneNamed:#"art.scnassets/Idle"];
for (SCNNode *childNode in standStillScene.rootNode.childNodes)
{
[node addChildNode:childNode];
}
node.scale = SCNVector3Make(0.1, 0.1, 0.1);
node.position = SCNVector3Make(0, 0,-2.5);
[sceneView.scene.rootNode addChildNode: node];
[self loadAnime:#"running" inScene:#"art.scnassets/Running" withID:#"Running-1"];
}
- (void)loadAnime:(NSString*)withKey inScene:(NSString*)scene withID:(NSString*)id
{
NSURL *url = [NSBundle.mainBundle URLForResource:scene withExtension:#"usdz"];
SCNSceneSource *source = [SCNSceneSource sceneSourceWithURL:url options:Nil];
CAAnimation *charAnimation = [source entryWithIdentifier:id
withClass:CAAnimation.self];
charAnimation.repeatCount = 1;
charAnimation.fadeInDuration = 1;
charAnimation.fadeOutDuration = 1;
[animations setValue:charAnimation forKey:withKey];
}
And at last touchesBegan:
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
CGPoint point = [touches.allObjects.firstObject locationInView: sceneView];
NSDictionary<SCNHitTestOption, id> *options = #{ SCNHitTestBoundingBoxOnlyKey: #(YES) };
NSArray<SCNHitTestResult *> *hitTestResults = [sceneView hitTest: point options: options];
if (notRunningSwitch == YES) {
[sceneView.scene.rootNode addAnimation:animations[#"running"] forKey:#"running"];
} else {
[sceneView.scene.rootNode removeAnimationForKey:#"running" blendOutDuration:1.0];
}
notRunningSwitch = !notRunningSwitch;
NSLog(#"%#", hitTestResults.firstObject.node.name);
NSLog(#"%f", hitTestResults.firstObject.modelTransform.m43);
}
#end