虽然我建议您在用户点击时放置对象以及他/她在屏幕上点击的位置，但您的要求可以这样实现。 （这个例子是在 Kotlin 中）
在开始放置对象之前，您需要创建一个ModelRenderable。全局声明一个@Nullable。
private var modelRenderable: ModelRenderable? = null
//Create the football renderable
ModelRenderable.builder()
//get the context of the ARFragment and pass the name of your .sfb file
.setSource(fragment.context, Uri.parse("FootBall.sfb"))
.build()
//I accepted the CompletableFuture using Async since I created my model on creation of the activity. You could simply use .thenAccept too.
//Use the returned modelRenderable and save it to a global variable of the same name
.thenAcceptAsync { modelRenderable -> this@MainActivity.modelRenderable = modelRenderable }
编程的主要部分必须在框架的onUpdate 方法上完成。所以你像这样为帧更新附加一个监听器
fragment.arSceneView.scene.addOnUpdateListener(this@MainActivity) //You can do this anywhere. I do it on activity creation post inflating the fragment
现在您处理在侦听器上添加一个对象。
override fun onUpdate(frameTime: FrameTime?) {
//get the frame from the scene for shorthand
val frame = fragment.arSceneView.arFrame
if (frame != null) {
//get the trackables to ensure planes are detected
val var3 = frame.getUpdatedTrackables(Plane::class.java).iterator()
while(var3.hasNext()) {
val plane = var3.next() as Plane
//If a plane has been detected & is being tracked by ARCore
if (plane.trackingState == TrackingState.TRACKING) {
//Hide the plane discovery helper animation
fragment.planeDiscoveryController.hide()
//Get all added anchors to the frame
val iterableAnchor = frame.updatedAnchors.iterator()
//place the first object only if no previous anchors were added
if(!iterableAnchor.hasNext()) {
//Perform a hit test at the center of the screen to place an object without tapping
val hitTest = frame.hitTest(frame.screenCenter().x, frame.screenCenter().y)
//iterate through all hits
val hitTestIterator = hitTest.iterator()
while(hitTestIterator.hasNext()) {
val hitResult = hitTestIterator.next()
//Create an anchor at the plane hit
val modelAnchor = plane.createAnchor(hitResult.hitPose)
//Attach a node to this anchor with the scene as the parent
val anchorNode = AnchorNode(modelAnchor)
anchorNode.setParent(fragment.arSceneView.scene)
//create a new TranformableNode that will carry our object
val transformableNode = TransformableNode(fragment.transformationSystem)
transformableNode.setParent(anchorNode)
transformableNode.renderable = this@MainActivity.modelRenderable
//Alter the real world position to ensure object renders on the table top. Not somewhere inside.
transformableNode.worldPosition = Vector3(modelAnchor.pose.tx(),
modelAnchor.pose.compose(Pose.makeTranslation(0f, 0.05f, 0f)).ty(),
modelAnchor.pose.tz())
}
}
}
}
}
}
我使用了一种扩展方法
//A method to find the screen center. This is used while placing objects in the scene
private fun Frame.screenCenter(): Vector3 {
val vw = findViewById<View>(android.R.id.content)
return Vector3(vw.width / 2f, vw.height / 2f, 0f)
}
这是最终结果