可以看到entity通过viewer中的entities加载到场景中，entities是entity的集合对象。这是一个最简单的示例，在场景中加一个点，可以看到需要以下属性：
//Ellipse
viewer.entities.add({
position: Cesium.Cartesian3.fromDegrees(103.0, 40.0),
name: 'Red ellipse on surface with outline',
ellipse: {
semiMinorAxis: 250000.0,
semiMajorAxis: 400000.0,
material: Cesium.Color.RED.withAlpha(0.5),
outline: true,
outlineColor: Cesium.Color.RED
}
});
//Corridor
viewer.entities.add({
name: 'Red corridor on surface with rounded corners and outline',
corridor: {
positions: Cesium.Cartesian3.fromDegreesArray([
100.0, 40.0,
105.0, 40.0,
105.0, 35.0
]),
width: 200000.0,
material: Cesium.Color.RED.withAlpha(0.5),
outline: true,
outlineColor: Cesium.Color.RED
}
});
//Cylinder
viewer.entities.add({
name: 'Green cylinder with black outline',
position: Cesium.Cartesian3.fromDegrees(100.0, 40.0, 200000.0),
cylinder: {
length: 400000.0,
topRadius: 200000.0,
bottomRadius: 200000.0,
material: Cesium.Color.GREEN.withAlpha(0.5),
outline: true,
outlineColor: Cesium.Color.DARK_GREEN
}
});
//Cone
viewer.entities.add({
name: 'Red cone',
position: Cesium.Cartesian3.fromDegrees(105.0, 40.0, 200000.0),
cylinder: {
length: 400000.0,
topRadius: 0.0,
bottomRadius: 200000.0,
material: Cesium.Color.RED
}
});
//Polygon
viewer.entities.add({
name: 'Red polygon on surface',
polygon: {
hierarchy: Cesium.Cartesian3.fromDegreesArray([115.0, 37.0,
115.0, 32.0,
107.0, 33.0,
102.0, 31.0,
102.0, 35.0]),
material: Cesium.Color.RED
}
});
//polyline
viewer.entities.add({
name: 'Red line on the surface',
polyline: {
positions: Cesium.Cartesian3.fromDegreesArray([75, 35,
125, 35]),
width: 5,
material: Cesium.Color.RED
}
});
//polylineVolume
function computeCircle(radius) {
var positions = [];
for (var i = 0; i < 360; i++) {
var radians = Cesium.Math.toRadians(i);
positions.push(new Cesium.Cartesian2(radius * Math.cos(radians), radius * Math.sin(radians)));
}
return positions;
}
viewer.entities.add({
name: 'Red tube with rounded corners',
polylineVolume: {
positions: Cesium.Cartesian3.fromDegreesArray([85.0, 32.0,
85.0, 36.0,
89.0, 36.0]),
shape: computeCircle(60000.0),
material: Cesium.Color.RED
}
});
//rectangle
viewer.entities.add({
name: 'Red translucent rectangle with outline',
rectangle: {
coordinates: Cesium.Rectangle.fromDegrees(80.0, 20.0, 110.0, 25.0),
material: Cesium.Color.RED.withAlpha(0.5),
outline: true,
outlineColor: Cesium.Color.RED
}
});
//Sphere
viewer.entities.add({
name: 'Red sphere with black outline',
position: Cesium.Cartesian3.fromDegrees(107.0, 40.0, 300000.0),
ellipsoid: {
radii: new Cesium.Cartesian3(300000.0, 300000.0, 300000.0),
material: Cesium.Color.RED.withAlpha(0.5),
outline: true,
outlineColor: Cesium.Color.BLACK
}
});
//ellipsoid
viewer.entities.add({
name: 'Blue ellipsoid',
position: Cesium.Cartesian3.fromDegrees(114.0, 40.0, 300000.0),
ellipsoid: {
radii: new Cesium.Cartesian3(200000.0, 200000.0, 300000.0),
material: Cesium.Color.BLUE
}
});
//wall
viewer.entities.add({
name: 'Green wall from surface with outline',
wall: {
positions: Cesium.Cartesian3.fromDegreesArrayHeights([107.0, 43.0, 100000.0,
97.0, 43.0, 100000.0,
97.0, 40.0, 100000.0,
107.0, 40.0, 100000.0,
107.0, 43.0, 100000.0]),
material: Cesium.Color.GREEN
}
});
