Ios 在ARKit中放置、拖动和删除SCNNodes

我正在用ARKit做一个小项目。我希望能够在点击时将对象添加到我的AR SceneView中，通过双击将其删除，并通过平移或拖动来拖动主题

最初点击以放置对象效果良好，但我在删除节点和拖动时遇到了一些问题

删除和拖动的主要问题是很难实际“按住”或单击SCNNode。大多数结果最终都不在我添加的SCNNode上

第二个问题是拖拽有点麻烦，SCNNode实际上没有我的手指在拖拽时移动那么多

我决定在github上创建一个项目，链接如下：

但我也会在这里发布我的删除对象和拖动对象的代码：

-(void)handleRemoveObject:(UITapGestureRecognizer *)recognizer {
    NSLog(@"Long Press Fired");
    CGPoint tapPoint = [recognizer locationInView:_sceneView];

    NSArray <SCNHitTestResult *> *result = [self.sceneView hitTest:tapPoint options:nil];

    if ([result count] == 0) {
        return;
    }
    SCNHitTestResult *hitResult = [result firstObject];
    if (hitResult.node) {
        [[hitResult.node parentNode] removeFromParentNode];
    }
}

-(void)moveObject:(UIPanGestureRecognizer *)recognizer {
    NSLog(@"Move object");
    if (recognizer.state == UIGestureRecognizerStateBegan) {
        NSLog(@"Pan state began");
        CGPoint tapPoint = [recognizer locationInView:_sceneView];
        NSArray <SCNHitTestResult *> *result = [self.sceneView hitTest:tapPoint options:nil];

        if ([result count] == 0) {
            return;
        }
        SCNHitTestResult *hitResult = [result firstObject];
        if ([hitResult.node.name isEqualToString:@"candle"]) {
            movedObject = [hitResult node];
        } else if ([[hitResult.node parentNode].name isEqualToString:@"candle"]) {
            movedObject = [[[hitResult node] parentNode] parentNode] parentNode];
        }
        if (movedObject){
            NSLog(@"Holding an Object");
        }
    }
    if (recognizer.state == UIGestureRecognizerStateChanged) {
        NSLog(@"Pan State Changed");
        if (movedObject) {

            CGPoint tapPoint = [recognizer locationInView:_sceneView];
            NSArray <ARHitTestResult *> *hitResults = [_sceneView hitTest:tapPoint types:ARHitTestResultTypeFeaturePoint];
            ARHitTestResult *result = [hitResults lastObject];

            SCNMatrix4 matrix = SCNMatrix4FromMat4(result.worldTransform);
            SCNVector3 vector = SCNVector3Make(matrix.m41, matrix.m42, matrix.m43);

            [movedObject setPosition:vector];
            NSLog(@"Moving object position");
        }
    }
    if (recognizer.state == UIGestureRecognizerStateEnded) {
        NSLog(@"Done moving object homeie");
        movedObject = nil;
    }
}

所以问题似乎是，我之前没有抓住整个物体，而是抓住了这个物体的一个子物体，当你试图拖动一个子物体时，由于某种原因，它会迫使物体移动缓慢。因此，我不得不做一些尝试和错误，以认识到我必须提高家长级别来解决这个问题

---

希望这有帮助

拖动对象的解决方案是将movedObject设置为[[[hitResult node]parentNode]parentNode]parentNode]，拖动变得更加平滑

如果你还没有，你可能想看看苹果的示例项目“在增强现实中放置虚拟对象”，请参阅该项目的url。这肯定涵盖了屏幕上的拖动部分。什么是“移动对象”？我没有看到声明。我正试图在swift中实现这一点，目前为止我已经做到了：@objc func-pangestree（发送方：uipangestrerecognizer）{let sceneView=sender.view as！ARSCNView let pannedLocation=sender.location（in:sceneView）let-hitTest=sceneView.hitTest（pannedLocation）if（sender.state==uigestrerecognizerState.start）{如果（！hitTest.isEmpty）{让sceneHitTestResult=hitTest.first！sceneView.scene.rootNode.chil=sceneHitTestResult.node.parent}movedObject只是一个对SCNNode的引用，该SCNNode在点击时被设置为开始状态，然后在平移手势的状态更改时被更新。它基本上只用于此函数。我使用swift，但请查看我的答案，了解如何拖动具有任意数量子节点的SCNNode。最基本的事情必须是done正在为要选择的对象指定一个

.categoryBitMask

-值，并且仅对具有该位掩码的对象进行hitTest，这样您就不会选择任何不需要的对象。git链接不起作用。请提供代码，以了解对象的放置方式。

-(void)moveObject:(UIPanGestureRecognizer *)recognizer {
    NSLog(@"Move object");
    if (recognizer.state == UIGestureRecognizerStateBegan) {
        NSLog(@"Pan state began");
        CGPoint tapPoint = [recognizer locationInView:_sceneView];
        NSArray <SCNHitTestResult *> *result = [self.sceneView hitTest:tapPoint options:nil];

        if ([result count] == 0) {
            return;
        }
        SCNHitTestResult *hitResult = [result firstObject];
        movedObject = [[[hitResult node] parentNode] parentNode] parentNode]; //This aspect varies based on the type of .SCN file that you have
        }
        if (movedObject){
            NSLog(@"Holding an Object");
        }
    }
    if (recognizer.state == UIGestureRecognizerStateChanged) {
        NSLog(@"Pan State Changed");
        if (movedObject) {

            CGPoint tapPoint = [recognizer locationInView:_sceneView];
            NSArray <ARHitTestResult *> *hitResults = [_sceneView hitTest:tapPoint types:ARHitTestResultTypeFeaturePoint];
            ARHitTestResult *result = [hitResults lastObject];

            SCNMatrix4 matrix = SCNMatrix4FromMat4(result.worldTransform);
            SCNVector3 vector = SCNVector3Make(matrix.m41, matrix.m42, matrix.m43);

            [movedObject setPosition:vector];
            NSLog(@"Moving object position");
        }
    }
    if (recognizer.state == UIGestureRecognizerStateEnded) {
        NSLog(@"Done moving object homeie");
        movedObject = nil;
    }
}