<!DOCTYPE html>
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<html lang="en">
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<head>
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<meta charset="utf-8" />
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<meta http-equiv="X-UA-Compatible" content="IE=edge" />
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<meta
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name="viewport"
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content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no"
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/>
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<meta name="description" content="Fog post process" />
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<meta
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name="cesium-sandcastle-labels"
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content="Showcases, Post Processing"
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/>
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<title>Cesium Demo</title>
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<script type="text/javascript" src="../Sandcastle-header.js"></script>
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<script type="text/javascript" src="../CesiumUnminified/Cesium.js"></script>
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</head>
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<body
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class="sandcastle-loading"
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data-sandcastle-bucket="bucket-requirejs.html"
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>
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<style>
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@import url(../templates/bucket.css);
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</style>
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<div id="cesiumContainer" class="fullSize"></div>
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<div id="loadingOverlay"><h1>Loading...</h1></div>
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<div id="toolbar"></div>
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<script id="cesium_sandcastle_script">
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function startup(Cesium) {
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"use strict";
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//Sandcastle_Begin
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var viewer = new Cesium.Viewer("cesiumContainer", {
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shouldAnimate: true,
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});
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if (!viewer.scene.context.depthTexture) {
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window.alert("This browser does not support the fog post process.");
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}
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var tileset = new Cesium.Cesium3DTileset({
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url: Cesium.IonResource.fromAssetId(40866),
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});
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viewer.scene.primitives.add(tileset);
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viewer.scene.camera.setView({
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destination: new Cesium.Cartesian3(
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1216356.033078094,
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-4736402.278325668,
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4081270.375520902
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),
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orientation: new Cesium.HeadingPitchRoll(
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0.08033365594766728,
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-0.29519015695063455,
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0.00027759141518046704
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),
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endTransform: Cesium.Matrix4.IDENTITY,
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});
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var fragmentShaderSource =
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"float getDistance(sampler2D depthTexture, vec2 texCoords) \n" +
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"{ \n" +
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" float depth = czm_unpackDepth(texture2D(depthTexture, texCoords)); \n" +
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" if (depth == 0.0) { \n" +
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" return czm_infinity; \n" +
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" } \n" +
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" vec4 eyeCoordinate = czm_windowToEyeCoordinates(gl_FragCoord.xy, depth); \n" +
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" return -eyeCoordinate.z / eyeCoordinate.w; \n" +
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"} \n" +
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"float interpolateByDistance(vec4 nearFarScalar, float distance) \n" +
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"{ \n" +
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" float startDistance = nearFarScalar.x; \n" +
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" float startValue = nearFarScalar.y; \n" +
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" float endDistance = nearFarScalar.z; \n" +
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" float endValue = nearFarScalar.w; \n" +
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" float t = clamp((distance - startDistance) / (endDistance - startDistance), 0.0, 1.0); \n" +
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" return mix(startValue, endValue, t); \n" +
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"} \n" +
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"vec4 alphaBlend(vec4 sourceColor, vec4 destinationColor) \n" +
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"{ \n" +
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" return sourceColor * vec4(sourceColor.aaa, 1.0) + destinationColor * (1.0 - sourceColor.a); \n" +
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"} \n" +
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"uniform sampler2D colorTexture; \n" +
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"uniform sampler2D depthTexture; \n" +
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"uniform vec4 fogByDistance; \n" +
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"uniform vec4 fogColor; \n" +
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"varying vec2 v_textureCoordinates; \n" +
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"void main(void) \n" +
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"{ \n" +
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" float distance = getDistance(depthTexture, v_textureCoordinates); \n" +
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" vec4 sceneColor = texture2D(colorTexture, v_textureCoordinates); \n" +
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" float blendAmount = interpolateByDistance(fogByDistance, distance); \n" +
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" vec4 finalFogColor = vec4(fogColor.rgb, fogColor.a * blendAmount); \n" +
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" gl_FragColor = alphaBlend(finalFogColor, sceneColor); \n" +
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"} \n";
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var ellipsoid = viewer.scene.globe.ellipsoid;
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var postProcessStage = viewer.scene.postProcessStages.add(
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new Cesium.PostProcessStage({
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fragmentShader: fragmentShaderSource,
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uniforms: {
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fogByDistance: new Cesium.Cartesian4(10, 0.0, 200, 1.0),
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fogColor: Cesium.Color.BLACK,
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},
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})
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); //Sandcastle_End
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Sandcastle.finishedLoading();
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}
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if (typeof Cesium !== "undefined") {
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window.startupCalled = true;
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startup(Cesium);
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}
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</script>
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</body>
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</html>
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