如何从对象获取坐标，即顶点

问题描述

我正在尝试一次获得一个顶点等几何数据.到目前为止，我尝试过的事情:

I am trying to get geometry data one element at a time such as vertices.What I tried so far:

• fragproxy = viewer.gui.impl.getFragmentProxy(model,fragid)给了我某种几何形状，但没有任何顶点，我可以通过dbId来访问

• fragproxy = viewer.gui.impl.getFragmentProxy(model,fragid) gives me some kind of geometry, but not any vertices, which I can access by dbId

frags = viewer.gui.model.getFragmentList()给了我一个从fragId到dbId的映射，但没有从dbId到几何的连接

frags = viewer.gui.model.getFragmentList() gives me a fragId to dbId map but no no connection from dbId to geometry

有人知道一种获取带有顶点的几何图形的方法吗?

Does anyone know a method to get the geometry with the vertices ?

推荐答案

以下代码段的positions值是您想要的顶点.

The positions value of the following code snippets is the vertices what you want.

  function getLeafFragIds( model, leafId ) {
    const instanceTree = model.getData().instanceTree;
    const fragIds = [];

    instanceTree.enumNodeFragments( leafId, function( fragId ) {
      fragIds.push( fragId );
    });

    return fragIds;
  }

  function getComponentGeometry( viewer, dbId ) {

    const fragIds = getLeafFragIds( viewer.model, dbId );

    let matrixWorld = null;

    const meshes = fragIds.map( function( fragId ) {

      const renderProxy = viewer.impl.getRenderProxy( viewer.model, fragId );

      const geometry = renderProxy.geometry;
      const attributes = geometry.attributes;
      const positions = geometry.vb ? geometry.vb : attributes.position.array;

      const indices = attributes.index.array || geometry.ib;
      const stride = geometry.vb ? geometry.vbstride : 3;
      const offsets = geometry.offsets;

      matrixWorld = matrixWorld || renderProxy.matrixWorld.elements;

      return {
        positions,
        indices,
        offsets,
        stride
      };
    });

    return {
      matrixWorld,
      meshes
    };
  }

  var meshInfo = getComponentGeometry( viewer, 1234 );

由于Forge片段的此信息存储在扁平存储器中，因此请检查演示扩展 Autodesk.ADN.Viewing.Extension.MeshData.js (如果需要)重建网格关系.

Since this information of the Forge fragment is stored in a flatten storage, please check the demo extension Autodesk.ADN.Viewing.Extension.MeshData.js if you want to rebuild the meshing relationship.

希望有帮助！

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