three.js 切割模型动画，并且播放

因为公司没有人会用blender，所以动画都是用max做的，动画师一般都是会把多个动画做在一个模型上，然后程序中需要使用的话，调用指定的帧数。unity可以把动画切割成animationclip。最近公司使用了需要在three.js中添加一个模型，模型带了一段长动画，所以我这边就是需要把模型的指定帧数之间的动画切割出来。

接下来演示部分：

1.准备素材一段带动画的素材 

初始化，加入相机，灯光模型等元素

function init() {

      var canHeight = window.innerHeight;
      var canWidth = window.innerWidth;
      container = document.createElement('div');

      camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 2000);
      camera.position.set(0, 150, 300);
      scene = new THREE.Scene();

      // ground
      var mesh = new THREE.Mesh(new THREE.PlaneBufferGeometry(2000, 2000), new THREE.MeshPhongMaterial({ color: 0x999999, depthWrite: false }));
      mesh.rotation.x = - Math.PI / 2;
      mesh.receiveShadow = true;
      scene.add(mesh);

      var grid = new THREE.GridHelper(2000, 20, 0x000000, 0x000000);
      grid.material.opacity = 0.2;
      grid.material.transparent = true;
      scene.add(grid);

      renderer = new THREE.WebGLRenderer({
        antialias: true,
        alpha: true
      });

      renderer.setPixelRatio(window.devicePixelRatio);
      renderer.setSize(window.innerWidth, window.innerHeight);
      renderer.shadowMap.enabled = true;
      container.appendChild(renderer.domElement);

      controls = new THREE.OrbitControls(camera, renderer.domElement);
      controls.target.set(0, 100, 0);
      controls.update();
      LoadModel();
      LoadLightModel();
      document.getElementById("threejsContainer").appendChild(renderer.domElement);
      window.addEventListener('resize', onWindowResize, false);
    }

    function LoadLightModel() {
      scene.background = new THREE.Color(0xa0a0a0);
      light = new THREE.HemisphereLight(0xffffff, 0x444444);
      light.position.set(0, 200, 0);
      scene.add(light);

      light = new THREE.DirectionalLight(0xffffff);
      light.position.set(0, 200, 100);
      light.castShadow = true;
      light.shadow.camera.top = 180;
      light.shadow.camera.bottom = - 100;
      light.shadow.camera.left = - 120;
      light.shadow.camera.right = 120;
      scene.add(light);

    }


    function LoadModel() {
      var femaleModel = new THREE.FBXLoader();
      femaleModel.load('../Model/Female_Match_Animation_H5.FBX', (object) => {
        object.scale.set(100, 100, 100);
        object.traverse(function (child) {

          if (child.isMesh) {
            if (child.name === 'head_base') {
              child.visible = false;
            }
            if (child.name === 'female_body_gai001') {
              child.material = new THREE.MeshBasicMaterial({
                map: new THREE.TextureLoader().load('../Model/map/female_body.jpg'),
                skinning: true,
                color: 0xffffff,
                side: THREE.DoubleSide
              });
            }
            if (child.name === 'female_head_26') {
              for (var i = 0; i < child.material.length; i++) {
                if (child.material[i].name === 'head_bozi_female_26_small_Std_Skin_Head') {
                  child.material[i] = new THREE.MeshBasicMaterial({
                    map: new THREE.TextureLoader().load(
                      '../Model/map/female_head_26.png'
                    ),
                    skinning: true,
                    color: 0xffffff,
                    morphTargets: true,
                    side: THREE.DoubleSide

                  });
                }

                if (child.material[i].name === 'Eyelash') {
                  child.material[i] = new THREE.MeshBasicMaterial({
                    map: new THREE.TextureLoader().load(
                      '../Model/map/female_Eyelash.png'
                    ),
                    skinning: true,
                    color: 0xffffff,
                    transparent: true,
                  });
                }
                if (child.material[i].name === 'Eye') {
                  child.material[i] = new THREE.MeshBasicMaterial({
                    map: new THREE.TextureLoader().load(
                      '../Model/map/female_eye.png'
                    ),
                    skinning: true,
                    color: 0xffffff,
                  });

                }
              }
            }
          }
        });
        model = object;
        scene.add(object);
      });

    }

导入模型之后如上图所示，这个时候并没有执行模型的动画，所以他就是没有动画的状态

2.切割three.js 需要使用的是THREE.AnimationUtils.subclip这个方法

我这边需要的是动作每一个动作的姿势，所以我只切割了一帧。如果大家需要的是一个动作的话就可以根据需要来切割

 function SetModelAnimationClip(action) {
      console.log(action)
      mixer = new THREE.AnimationMixer(model);
      var modelaction = model.animations[0];
      if (actionList.length == 0) {

        actionList.actionA = mixer.clipAction(THREE.AnimationUtils.subclip(modelaction, 'A', 59, 60));
        actionList.actionB = mixer.clipAction(THREE.AnimationUtils.subclip(modelaction, 'B', 129, 130));
        actionList.actionC = mixer.clipAction(THREE.AnimationUtils.subclip(modelaction, 'C', 199, 200));
        actionList.actionD = mixer.clipAction(THREE.AnimationUtils.subclip(modelaction, 'D', 270, 271));
        actionList.actionE = mixer.clipAction(THREE.AnimationUtils.subclip(modelaction, 'E', 399, 400));
        actionList.actionF = mixer.clipAction(THREE.AnimationUtils.subclip(modelaction, 'F', 529, 530));
        actionList.actionG = mixer.clipAction(THREE.AnimationUtils.subclip(modelaction, 'G', 599, 600));
        actionList.actionH = mixer.clipAction(THREE.AnimationUtils.subclip(modelaction, 'H', 668, 669));

      }
      actionClip = actionList['action' + action];
      actionClip.play();

    }

这里我把这些切割玩的动画放在了一个actionList中，以后需要调用的时候直接使用就可以了。

3.在界面中添加一些按钮这样就可以直接切换动作了

切换不同的动作。

遇到的问题：一开始我只引用了three.js这个脚本（单独的），在使用THREE.AnimationUtils.subclip这个方法的时候无法执行，代码也不会报错。可能是脚本插件不齐全吧,所以我用了我在vue中下载的比较完整的three的插件。

下载地址：https://download.csdn.net/download/AlZhuo/13577173