在Three.js中使用轨道控制旋转相机时发生奇怪的晃动 [英] Strange shaking while rotating the camera with Orbit Controls in Three.js
问题描述
我正在为太阳系建模。这是我当前的指标：
I'm making a model of the Solar System. This is my current metric:
scale = 0.001;
// 1 unit - 1 kilometer
var AU = 149597871 * scale;
这是我定义相机，渲染器和控件的方式：
This is how i define the camera, renderer and controls:
camera = new THREE.PerspectiveCamera(70, window.innerWidth / window.innerHeight, 0.1 * scale, 0.1 * AU);
renderer = new THREE.WebGLRenderer({ alpha: true, antialias: true });
controls = new THREE.OrbitControls(camera, renderer.domElement);
然后我为用户提供了在对象之间跳转的选项，因此这是我设置相机的方式用户选择一个行星/月球：
Then i give the user the option to jump between the objects so this is how i set the camera after user selects a planet/moon:
function cameraGoTo() {
for (var i = scene.children.length - 1; i >= 0 ; i--) {
var obj = scene.children[i];
if (obj.name == parameters.selected) {
controls.target = obj.position;
camera.position.copy(obj.position);
camera.position.y += obj.radius * 2;
}
}
}
问题是表示，对于小行星/月球（半径<= 1000 km），相机在绕天体旋转时会发抖。我只有计算机图形学的基本知识，所以我不知道这是Orbit Controls的问题，还是它与渲染器本身有关...所以我尝试设置 logarithmicDepthBuffer = true ，但没有帮助。尝试使用不同的比例也没有任何改变。
The problem is that for small planets/moons ( <= 1000 km in radius) camera is shaking while rotating around the object. I have only basic knowledge of computer graphics so i don't know either this is the problem of Orbit Controls or it has something to with renderer itself...so I've tried to set logarithmicDepthBuffer = true but it didn't help. Also trying different scale didn't change anything.
在此先感谢您的帮助/提示。
Thank in advance for any help/clues.
编辑：
这是小提琴：
http://jsfiddle.net/twxyz/8kxcdkjj/
您可以看到以下任何一种情况都会增加抖动：
You can see that shaking increases with any of the following:
- 对象越小
- 对象离原点越远
这是什么原因？显然，这似乎与相机的近/远光谱值无关，但与物体离场景中心的距离有关。
What is the cause of this? It clearly seems it has nothing to do with the camera near/far spectrum values but is related to the distance the objects are from the center of the scene.
推荐答案
我想出了解决方案。
我的问题是处理对象而不是对象时出现浮点精度错误。原点。事实证明这是一个众所周知的问题，并且有各种解决方案。我曾经用过这个：
My problem was with the floating point precision errors when dealing with objects far from the point of origin. This turns out to be a very known problem and there are various solutions. I've used this one:
http://answers.unity3d.com/questions/54739/any-solution-for-extreamly-large-gameworlds-single.html
发生的事情基本上不是移动摄像机/播放器，而是相对于始终位于原点的摄像机/播放器转换整个场景。在这种情况下，Orbit Controls的目标始终是起点。
What happens is basically instead of moving the camera/player, we transform whole scene relative to the camera/player that is always at the point of origin. In this case, Orbit Controls' target is always point of origin.
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