版本：3.8.5

实现目标：给3d道路生成路边景观花草

在场景下创建一个节点，我这里种植两种花草模型，兰花和菊花，所以分别在节点下另创建两个节点，为了静态合批。

 1.将花草模型分别拖入场景中，制作成预制文件。

 2.给plant节点绑定一个脚本，用来初始化生成植物。

一般道路是由平面连接成，所以需要先获取道路模型的网格顶点

    /*** 根据 道路路径获取两侧边界点* @param roadPath */public static getPointByRoad(roadPath: string) {try {let road = find(roadPath)let mesh = CommonUtil.getMeshRendererAdapter(road).meshlet pos = mesh.renderingSubMeshes[mesh.jointBufferIndices[0]].geometricInfo.positions;let result = []let worldMatrix = mat4();CommonUtil.getMeshRendererAdapter(road).node.getWorldMatrix(worldMatrix);for (let i = 0; i < pos.length; i += 3) {//顶点的本地坐标坐标转世界坐标let position=new Vec3()Vec3.fromArray(position, pos, i);let transform = v3();Vec3.transformMat4(transform, position, worldMatrix);result.push(transform)}return result} catch (e) {return []}}

如果模型面数比较大，数据就要进行抽稀

    public static dataDilution(data=[],deg:number=1){if(deg<=1||data.length==0){return data}let arr=[]for(let i=0;i<data.length;i+=deg){arr.push(data[i])}return arr}

现在就可以在plant脚本上进行创建使用了

    initData(){let arr = RoadsidePlantUtil.getPointByRoad(this.roadPath)arr = RoadsidePlantUtil.dataDilution(arr,2)let lanhuag=find(MarryManUtil.housPath + '/luduan/plant/lanhuag')let juhuag=find(MarryManUtil.housPath + '/luduan/plant/juhuag')for(let i=0;i<arr.length;i++){//y值小于-30不进行操作if(arr[i].y<-30){continue}let tty = Math.random() * 2if(tty<1){resources.load('prefab/flower/lanhua', Prefab, (err: any, data) => {if (!data) {return}let hua = instantiate(data)hua.parent = lanhuaghua.setPosition(v3(arr[i].x,arr[i].y,arr[i].z))})}else {resources.load('prefab/flower/juhua', Prefab, (err: any, data) => {if (!data) {return}let hua = instantiate(data)hua.parent = juhuaghua.setPosition(v3(arr[i].x,arr[i].y,arr[i].z))})}}}

效果如下