cesium/Apps/Sandcastle/gallery/Fog Post Process.html

117 lines
4.3 KiB
HTML

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