Question

我正在尝试构建一个Web应用程序，以使用户可以使用three.js观看360幅全景图像，但是某些代码无法正常工作。问题涉及旋转相机。

我能够通过听触摸事件或设备定向事件来旋转相机，但是我无法同时使两者同时工作。

当前，相机通过触摸手势旋转，但在检测到设备方向事件后会立即回弹。

我希望摄像头以触摸手势旋转，然后以设备方向旋转，从先前通过触摸设置的旋转开始。

我认为我应该改善 add-gestures.js 中的deviceorientation事件处理程序或setQuaternion方法，但我不知道如何。

index.html

<!doctype html>
<html>
  <head>
    <meta name="viewport" content="width=device-width,initial-scale=1">

    <link rel="stylesheet" href="pages/vr/style.css') ?>
  </head>

  <body>
    <canvas id="vr-canvas"></canvas>

    <script src="/js/lib/threejs/r104/build/three.min.js"></script>

    <script src="/js/pages/vr/init-vr.js"></script>
    <script src="/js/pages/vr/add-gestures.js"></script>
    <script src="/js/pages/vr/add-sphere.js"></script>
  </body>
</html>

init-vr.js

window.VRApp = window.VRApp || {};

const canvas = document.querySelector("#vr-canvas");

const renderer = (() => {
  const webGLRenderer = new THREE.WebGLRenderer({ canvas });

  webGLRenderer.setPixelRatio(window.devicePixelRatio);

  return webGLRenderer;
})();

const scene = new THREE.Scene();

const camera = (() => {
  const perspectiveCamera = new THREE.PerspectiveCamera(100, canvas.width / canvas.height, 0.01, 100);

  perspectiveCamera.rotation.order = "ZYX";

  return perspectiveCamera;
})();

const animate = () => {
  requestAnimationFrame(animate);

  renderer.render(scene, camera);
};

animate();

window.VRApp.renderer = renderer;
window.VRApp.scene = scene;
window.VRApp.camera = camera;

add-gestures.js

window.VRApp = window.VRApp || {};

const State = {
  Neutral: 0x0000,
  RotateCamera: 0x0001,
};

let state = State.Neutral;

let windowOrientation = window.orientation || 0;
let cameraRotationCache = window.VRApp.camera.rotation.clone();

let mousePositionCache = {
  x: 0,
  y: 0,
  minYDiff: 0,
  maxYDiff: 0,
};

const setState = (newState) => {
  if (State.hasOwnProperty(newState)) {
    state = State[newState];
  }
};

const checkState = (targetState) => {
  if (State.hasOwnProperty(targetState)) {
    return state === State[targetState];
  }

  return false;
};

const setQuaternion = (() => {
  const zee = new THREE.Vector3(0, 0, 1);
  const euler = new THREE.Euler();
  const q0 = new THREE.Quaternion();
  const q1 = new THREE.Quaternion(-1 * Math.sqrt(0.5), 0, 0, Math.sqrt(0.5));

  return (alpha, beta, gamma, orientation) => {
    euler.set(beta, alpha, -1 * gamma, "YXZ");

    window.VRApp.camera.quaternion.setFromEuler(euler);
    window.VRApp.camera.quaternion.multiply(q1);
    window.VRApp.camera.quaternion.multiply(q0.setFromAxisAngle(zee, -1 * orientation));
  };
})();

const onMouseDownHandler = (clientX, clientY) => {
  setState("RotateCamera");

  cameraRotationCache = window.VRApp.camera.rotation.clone();

  mousePositionCache.x = clientX;
  mousePositionCache.y = clientY;
  mousePositionCache.minYDiff = -90 - (cameraRotationCache.x * (180 / Math.PI)) - (clientY * (Math.PI / 180));
  mousePositionCache.maxYDiff = 90 - (cameraRotationCache.x * (180 / Math.PI)) - (clientY * (Math.PI / 180));
};


const onMouseMoveHandler = (clientX, clientY) => {
  if (checkState("RotateCamera")) {
    window.VRApp.camera.rotation.order = "ZYX";

    let xDiff = clientX - mousePositionCache.x;
    let yDiff = clientY - mousePositionCache.y;

    if (yDiff < mousePositionCache.minYDiff) {
      yDiff = mousePositionCache.minYDiff;

      mousePositionCache.y = clientY - mousePositionCache.minYDiff;
    }

    if (yDiff > mousePositionCache.maxYDiff) {
      yDiff = mousePositionCache.maxYDiff;

      mousePositionCache.y = clientY - mousePositionCache.maxYDiff;
    }

    let newAngleX = cameraRotationCache.x + (yDiff * (Math.PI / 180));
    let newAngleY = cameraRotationCache.y + (xDiff * (Math.PI / 180));

    window.VRApp.camera.rotation.x = newAngleX;
    window.VRApp.camera.rotation.y = newAngleY;
  }
};

const onMouseUpHandler = () => {
  setState("Neutral");

  cameraRotationCache = window.VRApp.camera.rotation.clone();

  mousePositionCache.x = 0;
  mousePositionCache.y = 0;
  mousePositionCache.minYDiff = 0;
  mousePositionCache.maxYDiff = 0;
};

if ("onresize" in window) {
  window.addEventListener("resize", (event) => {
    const width = window.innerWidth;
    const height = window.innerHeight;

    window.VRApp.renderer.domElement.width = width;
    window.VRApp.renderer.domElement.height = height;

    window.VRApp.renderer.domElement.style.height = height + "px";

    window.VRApp.renderer.setSize(width, height);

    window.VRApp.camera.aspect = width / height;
    window.VRApp.camera.updateProjectionMatrix();
  });
}

if ("onload" in window) {
  window.addEventListener("load", (event) => {
    const width = window.innerWidth;
    const height = window.innerHeight;

    window.VRApp.renderer.domElement.width = width;
    window.VRApp.renderer.domElement.height = height;

    window.VRApp.renderer.domElement.style.height = height + "px";

    window.VRApp.renderer.setSize(width, height);

    window.VRApp.camera.aspect = width / height;
    window.VRApp.camera.updateProjectionMatrix();
  });
}

if ("onmousedown" in window.VRApp.renderer.domElement) {
  window.VRApp.renderer.domElement.addEventListener("mousedown", (event) => {
    onMouseDownHandler(event.clientX, event.clientY);
  });
}

if ("onmousemove" in window.VRApp.renderer.domElement) {
  window.VRApp.renderer.domElement.addEventListener("mousemove", (event) => {
    onMouseMoveHandler(event.clientX, event.clientY);
  });
}

if ("onmouseup" in window.VRApp.renderer.domElement) {
  window.VRApp.renderer.domElement.addEventListener("mouseup", (event) => {
    onMouseUpHandler();
  });
}

if ("onmouseleave" in window.VRApp.renderer.domElement) {
  window.VRApp.renderer.domElement.addEventListener("mouseleave", (event) => {
    onMouseUpHandler();
  });
}

if ("ontouchstart" in window.VRApp.renderer.domElement) {
  window.VRApp.renderer.domElement.addEventListener("touchstart", (event) => {
    event.preventDefault();

    if (event.touches.length === 1) {
      const touch = event.touches[0];

      onMouseDownHandler(touch.clientX, touch.clientY);
    }
  });
}

if ("ontouchmove" in window.VRApp.renderer.domElement) {
  window.VRApp.renderer.domElement.addEventListener("touchmove", (event) => {
    event.preventDefault();

    if (event.touches.length === 1) {
      const touch = event.touches[0];

      onMouseMoveHandler(touch.clientX, touch.clientY);
    }
  });
}

if ("ontouchend" in window.VRApp.renderer.domElement) {
  window.VRApp.renderer.domElement.addEventListener("touchend", (event) => {
    event.preventDefault();

    onMouseUpHandler();
  });
}

if ("ontouchcancel" in window.VRApp.renderer.domElement) {
  window.VRApp.renderer.domElement.addEventListener("touchcancel", (event) => {
    event.preventDefault();

    onMouseUpHandler();
  });
}

if ("onorientationchange" in window) {
  window.addEventListener("orientationchange", (event) => {
    windowOrientation = window.orientation || 0;
  });
}

if ("ondeviceorientation" in window) {
  window.addEventListener("deviceorientation", (event) => {
    if (checkState("Neutral")) {
      let alpha = event.alpha * (Math.PI / 180);
      let beta = event.beta * (Math.PI / 180);
      let gamma = event.gamma * (Math.PI / 180);
      let orientation = windowOrientation * (Math.PI / 180);

      setQuaternion(alpha, beta, gamma, orientation);
    }
  });
}

add-sphere.js

window.VRApp = window.VRApp || {};

const sphere = (() => {
  const geometry = new THREE.SphereGeometry(100, 64, 64);

  geometry.scale(1, 1, -1);
  geometry.rotateY(Math.PI / 2);

  const material = new THREE.MeshBasicMaterial({
  });

  const mesh = new THREE.Mesh(geometry, material);

  return mesh;
})();

const textureLoader = new THREE.TextureLoader();
const texture = textureLoader.load("/img/pages/vr/sample-360.jpg");

sphere.material.map = texture;

window.VRApp.scene.add(sphere);

three.js相机通过触摸事件和设备定向事件旋转

0 个答案: