平湖网站建设公司,百度云app下载安装,旅游网站建设注册,网站 app建设开发合作协议最近整理了下手上的代码#xff0c;以下是对模型压平的说明。
原理是使用了customShader来重新设置了模型的着色器#xff0c;通过修改模型顶点的坐标来实现了压平。
废话不多说#xff0c;下面上代码#xff1a;
/*** class* description 3dtiles模型压平*/
class Flat…最近整理了下手上的代码以下是对模型压平的说明。
原理是使用了customShader来重新设置了模型的着色器通过修改模型顶点的坐标来实现了压平。
废话不多说下面上代码
/*** class* description 3dtiles模型压平*/
class Flat {/*** * param {Cesium.Cesium3DTileset} tileset 三维模型* param {Object} opt * param {Number} opt.flatHeight 压平高度 */constructor(tileset, opt) {if (!tileset) return;this.tileset tileset;this.opt opt || {};this.flatHeight this.opt.flatHeight || 0;this.center tileset.boundingSphere.center.clone();this.matrix Cesium.Transforms.eastNorthUpToFixedFrame(this.center.clone());this.localMatrix Cesium.Matrix4.inverse(this.matrix, new Cesium.Matrix4());// 多面的坐标数组this.regionList [];// 多个面坐标转为局部模型坐标this.localPositionsArr [];}/*** 添加压平面* param {Object} attr 参数* param {Cesium.Cartesian3[]} attr.positions 压平面坐标* param {Number} attr.height 压平深度当前不支持单独设置* param {Number} attr.id 唯一标识*/addRegion(attr) {let { positions, height, id } attr || {};// this.flatHeight height;if (!id) id (new Date()).getTime() Number(Math.random() * 1000).toFixed(0);this.regionList.push(attr);for (let i 0; i this.regionList.length; i) {let item this.regionList[i];const positions item.positions;let localCoor this.cartesiansToLocal(positions);this.localPositionsArr.push(localCoor);}const funstr this.getIsinPolygonFun(this.localPositionsArr);let str ;for (let i 0; i this.localPositionsArr.length; i) {const coors this.localPositionsArr[i];const n coors.length;let instr ;coors.forEach((coordinate, index) {instr points_${n}[${index}] vec2(${coordinate[0]}, ${coordinate[1]});\n;})str ${instr}if(isPointInPolygon_${n}(position2D)){vec4 tileset_local_position_transformed vec4(tileset_local_position.x, tileset_local_position.y, ground_z, 1.0);vec4 model_local_position_transformed czm_inverseModel * u_tileset_localToWorldMatrix * tileset_local_position_transformed;vsOutput.positionMC.xy model_local_position_transformed.xy;vsOutput.positionMC.z model_local_position_transformed.z modelMC.z*0.002;return;};}this.updateShader(funstr, str);}/*** 根据id删除压平的面* param {String} id 唯一标识*/removeRegionById(id) {if (!id) return;this.regionList this.regionList.filter((attr) {return attr.id ! id;})this.localPositionsArr [];for (let i 0; i this.regionList.length; i) {let item this.regionList[i];const positions item.positions;let localCoor this.cartesiansToLocal(positions);this.localPositionsArr.push(localCoor);}const funstr this.getIsinPolygonFun(this.localPositionsArr);let str ;for (let i 0; i this.localPositionsArr.length; i) {const coors this.localPositionsArr[i];const n coors.length;let instr ;coors.forEach((coordinate, index) {instr points_${n}[${index}] vec2(${coordinate[0]}, ${coordinate[1]});\n;})str ${instr}if(isPointInPolygon_${n}(position2D)){vec4 tileset_local_position_transformed vec4(tileset_local_position.x, tileset_local_position.y, ground_z, 1.0);vec4 model_local_position_transformed czm_inverseModel * u_tileset_localToWorldMatrix * tileset_local_position_transformed;vsOutput.positionMC.xy model_local_position_transformed.xy;vsOutput.positionMC.z model_local_position_transformed.z modelMC.z*0.002;return;};}this.updateShader(funstr, str);}/*** 销毁*/destroy() {this.tileset.customShader undefined;}/*** 根据数组长度构建 判断点是否在面内 的压平函数*/getIsinPolygonFun(polygons) {let pmap polygons.map((polygon) polygon.length);let uniqueArray this.getUniqueArray(pmap);let str ;uniqueArray.forEach(length {str vec2 points_${length}[${length}];bool isPointInPolygon_${length}(vec2 point){int nCross 0; // 交点数const int n ${length}; for(int i 0; i n; i){vec2 p1 points_${length}[i];vec2 p2 points_${length}[int(mod(float(i1),float(n)))];if(p1[1] p2[1]){continue;}if(point[1] min(p1[1], p2[1])){continue;}if(point[1] max(p1[1], p2[1])){continue;}float x p1[0] ((point[1] - p1[1]) * (p2[0] - p1[0])) / (p2[1] - p1[1]);if(x point[0]){nCross;}}return int(mod(float(nCross), float(2))) 1;}})return str}updateShader(vtx1, vtx2) {let flatCustomShader new Cesium.CustomShader({uniforms: {u_tileset_localToWorldMatrix: {type: Cesium.UniformType.MAT4,value: this.matrix,},u_tileset_worldToLocalMatrix: {type: Cesium.UniformType.MAT4,value: this.localMatrix,},u_flatHeight: {type: Cesium.UniformType.FLOAT,value: this.flatHeight,},},vertexShaderText: // 所有isPointInPolygon函数${vtx1}void vertexMain(VertexInput vsInput, inout czm_modelVertexOutput vsOutput){vec3 modelMC vsInput.attributes.positionMC;vec4 model_local_position vec4(modelMC.x, modelMC.y, modelMC.z, 1.0);vec4 tileset_local_position u_tileset_worldToLocalMatrix * czm_model * model_local_position;vec2 position2D vec2(tileset_local_position.x,tileset_local_position.y);float ground_z 0.0 u_flatHeight;// 多个多边形区域${vtx2}},});this.tileset.customShader flatCustomShader;}// 数组去重不能处理嵌套的数组getUniqueArray (arr) {return arr.filter(function (item, index, arr) {//当前元素在原始数组中的第一个索引当前索引值否则返回当前元素return arr.indexOf(item, 0) index;});}// 世界坐标转数组局部坐标cartesiansToLocal(positions) {let arr [];for (let i 0; i positions.length; i) {let position positions[i];let localp Cesium.Matrix4.multiplyByPoint(this.localMatrix,position.clone(),new Cesium.Cartesian3())arr.push([localp.x, localp.y]);}return arr;}}export default Flat;
调用方式
let flatTool new Flat(tileset, {flatHeight: -30});flatTool.addRegion({positions : positions,id : new Date().getTime()});
以下是仓库地址
CesiumExp-tilesetFlat: 3dtiles模型压平
