如何更新几何顶点位置Objloader [英] How to update the Geometry vertex position Objloader

问题描述

我使用objloader加载多个对象。我正在尝试移动其中一个对象，并需要更新顶点位置。加载对象时，我将缓冲几何转换为几何并运行一些函数。我检查了所有更新缓冲区几何顶点的样本。我是否需要将其转换回缓冲区？
我需要在移动时计算一些其他函数的实时位置，所以我不想继续从缓冲区转换到几何，反之亦然。

I am using objloader to load multiple objects. I am trying to move one of the objects and need to have the updated vertex positions. while loading the objects I converted the buffergeometry to geometry and run some functions. I checked some samples all updating the vertices of the buffergeometry. Do I need to convert it back to buffergeometry or not ? I need to have the real time positions while moving to calculate some other functions, so I prefer not to keep on converting from buffer to geometry and vice versa.

以下是一段代码：

Here is a piece of code:

          var tool= new THREE.OBJLoader();
          tool.load( '../obj/tool.obj', function ( object ) {
          var material = new THREE.MeshLambertMaterial({color:0xA0A0A0});             
          object.traverse( function ( child ) {
          if ( child instanceof THREE.Mesh ) {
               child.material = material;
               Geometry = new THREE.Geometry().fromBufferGeometry(child.geometry);
              }

          console.log(Geometry.vertices[220]);
          Geometry.position.x += 0.01;
          Geometry.verticesNeedUpdate = true;
          console.log(Geometry.vertices[220]);

另外，我检查了迁移文件最新版本并检出它们。

Besides, I checked the migration document of the latest versions and checked them out.

推荐答案

OBJLoader returns BufferGeometry 。您可以像这样更新顶点位置：

OBJLoader returns BufferGeometry. You can update a vertex position like so:

geometry.attributes.position.setX( index, x );

geometry.attributes.position.setXYZ( index, x, y, z ); // alternate

geometry.attributes.position.needsUpdate = true; // only required if geometry previously-rendered

研究 http://threejs.org/docs/#Reference/Core/BufferAttribute

相反，您可以转换为几何。在你的情况下，在加载器回调中执行以下操作：

Instead, you can convert to Geometry. In your case, do the following in the loader callback:

child.geometry = new THREE.Geometry().fromBufferGeometry( child.geometry );

然后使用这种模式更新顶点位置：

You then update a vertex position using this pattern:

geometry.vertices[ 0 ].set( x, y, z );
geometry.verticesNeedUpdate = true;

如果几何图形只设置 needsUpdate 已经被提交。

Only set the needsUpdate flag if the geometry has been previously rendered.

three.js r.71

three.js r.71

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