Bug in "Geometry Instances" tutorial

CesiumJS
1

1. A concise explanation of the problem you’re experiencing.

Code in https://cesiumjs.org/tutorials/Geometry-and-Appearances/#geometry-instances has a bug

2. A minimal code example. If you’ve found a bug, this helps us reproduce and repair it.

Here is the fix

var viewer = new Cesium.Viewer(‘cesiumContainer’);
var scene = viewer.scene;

var ellipsoidGeometry = new Cesium.EllipsoidGeometry({
vertexFormat : Cesium.PerInstanceColorAppearance.VERTEX_FORMAT,
radii : new Cesium.Cartesian3(300000.0, 200000.0, 150000.0)
});

var cyanEllipsoidInstance = new Cesium.GeometryInstance({
geometry : ellipsoidGeometry,
modelMatrix : Cesium.Matrix4.multiplyByTranslation(
Cesium.Transforms.eastNorthUpToFixedFrame(Cesium.Cartesian3.fromDegrees(-100.0, 40.0)),
new Cesium.Cartesian3(0.0, 0.0, 150000.0),
new Cesium.Matrix4()
),
attributes : {
color : Cesium.ColorGeometryInstanceAttribute.fromColor(Cesium.Color.CYAN)
}
});

var orangeEllipsoidInstance = new Cesium.GeometryInstance({
geometry : ellipsoidGeometry,
modelMatrix : Cesium.Matrix4.multiplyByTranslation(
Cesium.Transforms.eastNorthUpToFixedFrame(Cesium.Cartesian3.fromDegrees(-100.0, 40.0)),
new Cesium.Cartesian3(0.0, 0.0, 450000.0),
new Cesium.Matrix4()
),
attributes : {
color : Cesium.ColorGeometryInstanceAttribute.fromColor(Cesium.Color.ORANGE)
}
});

scene.primitives.add(new Cesium.Primitive({
geometryInstances : [cyanEllipsoidInstance, orangeEllipsoidInstance],
appearance : new Cesium.PerInstanceColorAppearance({
translucent : false,
closed : true
})
}));

``

3. Context. Why do you need to do this? We might know a better way to accomplish your goal.

Trying to figure out how to place instances.

4. The Cesium version you’re using, your operating system and browser.

Win 7, latest chrome and cesium

2

Thanks for reporting the issue and supplying the fix Patrick.h! I've submitted a pull request and should get that fixed soon.

3

Should be all good now!