Orillusion

    const geometry = new GeometryBase();
    geometry.setIndices(indices_arr);
    geometry.setAttribute(VertexAttributeName.position, position_arr);
    geometry.setAttribute(VertexAttributeName.normal, normal_arr);
            geometry.addSubGeometry({
                indexStart: 0,
                indexCount: indices_arr.length,
                vertexStart: 0,
                index: 0,
            });

不知道这样能否满足你的需求