Cesium 与 Babylon.js 可视化 glsl 特效篇（十六）

Posted 2023-03-15 haibalai

我决定不从Babylonjs 基础来讲了 直接整合cesium与babylonjs可视化来讲

我整合一个类库 后续不断更新中

• npm i @haibalai/cesium-babylonjs

 

初始化cesium -babylonjs 类库， map 是cesium 的viewer对象

• import  BabylonMapManager from "@haibalai/cesium-babylonjs";
• BabylonMapManager.init(map);

 

添加特效

• import BabylonMapManager  from "@haibalai/cesium-babylonjs";
• const fragmentShader = `
• precision highp float;
• uniform float iTime;
• const vec2 iResolution = vec2(1.0,1.0);
• varying vec2 vUv;
• vec3 rY(vec3 p, float a)
• vec3 q = p;
• float c = cos(a);
• float s = sin(a);
• q.x = c * p.x + s * p.z;
• q.z = -s * p.x + c * p.z;
• return q;
• // returns a pair of values for the distances along the ray at which there are sphere intersections, or 0 if none
• vec2 sphereIntersectionDistances(vec3 rayOrigin, vec3 rayDirection, vec3 sphereOrigin, float sphereRadius)
• vec3 toCenter = sphereOrigin - rayOrigin;
• float toCenterAlongRay = dot(toCenter, rayDirection);
• float perpendicularDistanceSquared = dot(toCenter, toCenter) - toCenterAlongRay * toCenterAlongRay;
• float radiusSquared = sphereRadius * sphereRadius;
• if (perpendicularDistanceSquared > radiusSquared)  // ray doesn’t touch the sphere
• return vec2(0.);
• float insideSphereAlongRay = sqrt(radiusSquared - perpendicularDistanceSquared); // half the length of the portion of the ray inside the sphere
• float intersection1 = toCenterAlongRay - insideSphereAlongRay;
• float intersection2 = toCenterAlongRay + insideSphereAlongRay;

Cesium 与 Babylon.js 可视化 glsl 特效篇（十六） － 小专栏