# Is it possible to change the length of an existing cylinder?

**URL:** <https://community.cesium.com/t/is-it-possible-to-change-the-length-of-an-existing-cylinder/780>\
**Category:** CesiumJS\
**Created:** [October 16, 2013, 4:46pm UTC](https://community.cesium.com/t/is-it-possible-to-change-the-length-of-an-existing-cylinder/780 "2013-10-16T16:46:30Z")\
**Posts on this page:** 14\
**Page:** 1

<div class="post-metadata">

**Author:** ![max1](https://avatars.discourse-cdn.com/v4/letter/m/e99b99/32.png) [@max1](https://community.cesium.com/u/max1)\
**Post date:** [October 16, 2013, 4:46pm UTC](https://community.cesium.com/t/is-it-possible-to-change-the-length-of-an-existing-cylinder/780/1 "2013-10-16T16:46:30Z")

</div>

Removing and adding a new one causes too much flicker.

---

<div class="post-metadata">

**Author:** ![patrick](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/patrick/32/2045_2.png) [@patrick](https://community.cesium.com/u/patrick)\
**Post date:** [October 17, 2013, 12:31am UTC](https://community.cesium.com/t/is-it-possible-to-change-the-length-of-an-existing-cylinder/780/2 "2013-10-17T00:31:40Z")

</div>

If you have a single cylinder in a primitive, you can use the modelMatrix to change the scale, and thus the height, of the cylinder. See [Matrix4.fromUniformScale](http://cesium.agi.com/Cesium/Build/Documentation/Matrix4.html#fromUniformScale).

If you have several cylinders in a primitive, it is possible to write a custom appearance that allows per-instance cylinder height and applies it in the vertex shader. We may add an example like this to the tutorial since other folks have asked a similar question about changing the height of a polygon.

Patrick

---

<div class="post-metadata">

**Author:** ![David3](https://avatars.discourse-cdn.com/v4/letter/d/f475e1/32.png) [@David3](https://community.cesium.com/u/David3)\
**Post date:** [August 7, 2014, 4:27pm UTC](https://community.cesium.com/t/is-it-possible-to-change-the-length-of-an-existing-cylinder/780/3 "2014-08-07T16:27:49Z")

</div>

any update on this?

---

<div class="post-metadata">

**Author:** ![patrick](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/patrick/32/2045_2.png) [@patrick](https://community.cesium.com/u/patrick)\
**Post date:** [August 7, 2014, 10:28pm UTC](https://community.cesium.com/t/is-it-possible-to-change-the-length-of-an-existing-cylinder/780/4 "2014-08-07T22:28:44Z")

</div>

Hi David,

No update on a custom appearance, but this is a reasonable approach if you don’t have 1,000 of cylinders:

> If you have a single cylinder in a primitive, you can use the modelMatrix to change the scale, and thus the height, of the cylinder. See [Matrix4.fromUniformScale](http://cesium.agi.com/Cesium/Build/Documentation/Matrix4.html#fromUniformScale).

Patrick

---

<div class="post-metadata">

**Author:** ![David3](https://avatars.discourse-cdn.com/v4/letter/d/f475e1/32.png) [@David3](https://community.cesium.com/u/David3)\
**Post date:** [August 8, 2014, 3:44pm UTC](https://community.cesium.com/t/is-it-possible-to-change-the-length-of-an-existing-cylinder/780/5 "2014-08-08T15:44:34Z")

</div>

I don’t exactly understand the documentation.  
So this would increase the all around size of the cylinder not just the height right?

I want to be able to adjust the height, and radius seperately (for testing purposes to have height and radius change by a trackbar)

---

<div class="post-metadata">

**Author:** ![David3](https://avatars.discourse-cdn.com/v4/letter/d/f475e1/32.png) [@David3](https://community.cesium.com/u/David3)\
**Post date:** [August 8, 2014, 4:37pm UTC](https://community.cesium.com/t/is-it-possible-to-change-the-length-of-an-existing-cylinder/780/6 "2014-08-08T16:37:49Z")

</div>

Also I have been attempting to use that function but I’m not sure how.

Here is my sample sandcastle code. [https://cesiumjs.org/Cesium/Apps/Sandcastle/index.html](https://cesiumjs.org/Cesium/Apps/Sandcastle/index.html)

var viewer = new Cesium.Viewer(‘cesiumContainer’, {

sceneMode: Cesium.SceneMode.COLUMBUS\_VIEW,

//Hide the base layer picker

baseLayerPicker: false,

//Use BingMaps

imageryProvider: new Cesium.BingMapsImageryProvider({

url: ‘[//dev.virtualearth.net](https://dev.virtualearth.net)’,

mapStyle: Cesium.BingMapsStyle.ROAD

}),

fullscreenButton: false,

homeButton: false,

navigationHelpButton: false,

navigationInstructionsInitiallyVisible: false,

animation: false,

geocoder: false,

infobox: false,

sceneModePicker: false,

selectionIndicator: false,

timeline: false

});

Sandcastle.addToolbarButton(‘Matrix4.fromScale(2.0)’, function() {

var CurrentModelMatrix = primitives.get(0).geometryInstances[0].modelMatrix;

CurrentModelMatrix = Cesium.Matrix4.fromScale(2.0);

});

Sandcastle.addToolbarButton(‘Matrix4.fromScale(3.0)’, function() {

var CurrentModelMatrix = primitives.get(0).geometryInstances[0].modelMatrix;

CurrentModelMatrix = Cesium.Matrix4.fromScale(3.0);

});

Sandcastle.addToolbarButton(‘Matrix4.fromScale(4.0)’, function() {

var CurrentModelMatrix = primitives.get(0).geometryInstances[0].modelMatrix;

CurrentModelMatrix = Cesium.Matrix4.fromScale(2.0);

});

var scene = viewer.scene;

var primitives = scene.primitives;

function flyTo(x,y) {

try {

viewer.scene.camera.flyTo({

destination: Cesium.Cartesian3.fromDegrees(x - .006,y - .015, 2000.0),

up: new Cesium.Cartesian3(0.0, 0.0, 1),

direction: new Cesium.Cartesian3(0.3, 0.5, -.5)

});

}

catch (e) {

alert(e.message);

}

}

var positionOnEllipsoid = Cesium.Cartesian3.fromDegrees(-120.0, 40.0);

var modelMatrix = Cesium.Matrix4.multiplyByTranslation(

Cesium.Transforms.eastNorthUpToFixedFrame(positionOnEllipsoid),

new Cesium.Cartesian3(0.0, 0.0, length \* 0.5), new Cesium.Matrix4()

);

// Create the cylinder geometry.

var cylinderGeometry = new Cesium.CylinderGeometry({

length : 1000.0,

topRadius : 100.0,

bottomRadius : 100.0,

vertexFormat : Cesium.PerInstanceColorAppearance.VERTEX\_FORMAT

});

// Create a geometry instance using the cylinder geometry

// created above. We can also specify a color attribute,

// in this case, we’re creating a solid green color.

var greenCylinder = new Cesium.GeometryInstance({

geometry : cylinderGeometry,

modelMatrix : modelMatrix,

attributes : {

color : Cesium.ColorGeometryInstanceAttribute.fromColor(Cesium.Color.GREEN)

}

});

primitives.add(new Cesium.Primitive({

releaseGeometryInstances: false,

geometryInstances : [greenCylinder],

appearance : new Cesium.PerInstanceColorAppearance({

closed : true,

translucent: false

})

}));

flyTo(-120,40);

``

---

<div class="post-metadata">

**Author:** ![patrick](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/patrick/32/2045_2.png) [@patrick](https://community.cesium.com/u/patrick)\
**Post date:** [August 9, 2014, 2:20am UTC](https://community.cesium.com/t/is-it-possible-to-change-the-length-of-an-existing-cylinder/780/7 "2014-08-09T02:20:28Z")

</div>

The modelMatrix doesn’t have to change the overall size. Use non-uniform scale (and you’ll probably want a translation too). For example, if Z is up, then we only want to scale in the Z direction. See [Matrix4.fromScale](https://github.com/AnalyticalGraphicsInc/cesium/blob/master/Source/Core/Matrix4.js#L425). Sorry, I posted the wrong scale function before.

Patrick

---

<div class="post-metadata">

**Author:** ![David3](https://avatars.discourse-cdn.com/v4/letter/d/f475e1/32.png) [@David3](https://community.cesium.com/u/David3)\
**Post date:** [August 10, 2014, 2:48pm UTC](https://community.cesium.com/t/is-it-possible-to-change-the-length-of-an-existing-cylinder/780/8 "2014-08-10T14:48:10Z")

</div>

That seems like it should do the trick, could you possibly give me a sandcastle example so I could see how it works? my previous example should change the size but it does nothing. Thanks for your help Patrick.

---

<div class="post-metadata">

**Author:** ![David3](https://avatars.discourse-cdn.com/v4/letter/d/f475e1/32.png) [@David3](https://community.cesium.com/u/David3)\
**Post date:** [August 13, 2014, 2:46pm UTC](https://community.cesium.com/t/is-it-possible-to-change-the-length-of-an-existing-cylinder/780/9 "2014-08-13T14:46:52Z")

</div>

> That seems like it should do the trick, could you possibly give me a sandcastle example so I could see how it works? my previous example should change the size but it does nothing. Thanks for your help Patrick.

> >

> > Patrick

> > The modelMatrix doesn’t have to change the overall size. Use non-uniform scale (and you’ll probably want a translation too). For example, if Z is up, then we only want to scale in the Z direction. See [Matrix4.fromScale](https://github.com/AnalyticalGraphicsInc/cesium/blob/master/Source/Core/Matrix4.js#L425). Sorry, I posted the wrong scale function before.

> > > Also I have been attempting to use that function but I’m not sure how.  
> > > Here is my sample sandcastle code. [https://cesiumjs.org/Cesium/Apps/Sandcastle/index.html](https://cesiumjs.org/Cesium/Apps/Sandcastle/index.html)
> > > 
> > > var viewer = new Cesium.Viewer(‘cesiumContainer’, {

> > > sceneMode: Cesium.SceneMode.COLUMBUS\_VIEW,

> > > //Hide the base layer picker

> > > baseLayerPicker: false,

> > > //Use BingMaps

> > > imageryProvider: new Cesium.BingMapsImageryProvider({

> > > url: ‘//[dev.virtualearth.net](http://dev.virtualearth.net)’,

> > > mapStyle: Cesium.BingMapsStyle.ROAD

> > > }),

> > > fullscreenButton: false,

> > > homeButton: false,

> > > navigationHelpButton: false,

> > > navigationInstructionsInitiallyVisible: false,

> > > animation: false,

> > > geocoder: false,

> > > infobox: false,

> > > sceneModePicker: false,

> > > selectionIndicator: false,

> > > timeline: false

> > >

> > > });

> > > Sandcastle.addToolbarButton(‘Matrix4.fromScale(2.0)’, function() {

> > > var CurrentModelMatrix = primitives.get(0).geometryInstances[0].modelMatrix;

> > > CurrentModelMatrix = Cesium.Matrix4.fromScale(2.0);

> > > });

> > > Sandcastle.addToolbarButton(‘Matrix4.fromScale(3.0)’, function() {

> > > var CurrentModelMatrix = primitives.get(0).geometryInstances[0].modelMatrix;

> > > CurrentModelMatrix = Cesium.Matrix4.fromScale(3.0);

> > > });

> > > Sandcastle.addToolbarButton(‘Matrix4.fromScale(4.0)’, function() {

> > > var CurrentModelMatrix = primitives.get(0).geometryInstances[0].modelMatrix;

> > > CurrentModelMatrix = Cesium.Matrix4.fromScale(2.0);

> > > });

> > > var scene = viewer.scene;

> > > var primitives = scene.primitives;

> > >

> > > function flyTo(x,y) {

> > > try {

> > > viewer.scene.camera.flyTo({

> > > destination: Cesium.Cartesian3.fromDegrees(x - .006,y - .015, 2000.0),

> > > up: new Cesium.Cartesian3(0.0, 0.0, 1),

> > > direction: new Cesium.Cartesian3(0.3, 0.5, -.5)

> > > });

> > > }

> > > catch (e) {

> > > alert(e.message);

> > > }

> > > }

> > > var positionOnEllipsoid = Cesium.Cartesian3.fromDegrees(-120.0, 40.0);

> > > var modelMatrix = Cesium.Matrix4.multiplyByTranslation(

> > > Cesium.Transforms.eastNorthUpToFixedFrame(positionOnEllipsoid),

> > > new Cesium.Cartesian3(0.0, 0.0, length \* 0.5), new Cesium.Matrix4()

> > > );

> > > // Create the cylinder geometry.

> > > var cylinderGeometry = new Cesium.CylinderGeometry({

> > > length : 1000.0,

> > > topRadius : 100.0,

> > > bottomRadius : 100.0,

> > > vertexFormat : Cesium.PerInstanceColorAppearance.VERTEX\_FORMAT

> > > });

> > > // Create a geometry instance using the cylinder geometry

> > > // created above. We can also specify a color attribute,

> > > // in this case, we’re creating a solid green color.

> > > var greenCylinder = new Cesium.GeometryInstance({

> > > geometry : cylinderGeometry,

> > > modelMatrix : modelMatrix,

> > > attributes : {

> > > color : Cesium.ColorGeometryInstanceAttribute.fromColor(Cesium.Color.GREEN)

> > > }

> > > });

> > > primitives.add(new Cesium.Primitive({

> > > releaseGeometryInstances: false,

> > > geometryInstances : [greenCylinder],

> > > appearance : new Cesium.PerInstanceColorAppearance({

> > > closed : true,

> > > translucent: false

> > > })

> > > }));

> > > flyTo(-120,40);

> > > ``

> > > > I don’t exactly understand the documentation.  
> > > > So this would increase the all around size of the cylinder not just the height right?

> > > > I want to be able to adjust the height, and radius seperately (for testing purposes to have height and radius change by a trackbar)
> > > > 
> > > > > Hi David,

> > > > > No update on a custom appearance, but this is a reasonable approach if you don’t have 1,000 of cylinders:

> > > > >

> > > > > > If you have a single cylinder in a primitive, you can use the modelMatrix to change the scale, and thus the height, of the cylinder. See [Matrix4.fromUniformScale](http://cesium.agi.com/Cesium/Build/Documentation/Matrix4.html#fromUniformScale).

> > > > >

> > > > > Patrick

> > > > > > any update on this?
> > > > > > 
> > > > > > > If you have a single cylinder in a primitive, you can use the modelMatrix to change the scale, and thus the height, of the cylinder. See [Matrix4.fromUniformScale](http://cesium.agi.com/Cesium/Build/Documentation/Matrix4.html#fromUniformScale).

> > > > > > > If you have several cylinders in a primitive, it is possible to write a custom appearance that allows per-instance cylinder height and applies it in the vertex shader. We may add an example like this to the tutorial since other folks have asked a similar question about changing the height of a polygon.

> > > > > > >

> > > > > > > Patrick

> > > > > > > > Removing and adding a new one causes too much flicker.

> > > > > > –
> > > > > > 
> > > > > > You received this message because you are subscribed to a topic in the Google Groups “cesium-dev” group.
> > > > > > 
> > > > > > To unsubscribe from this topic, visit [https://groups.google.com/d/topic/cesium-dev/uFjOz5F0uK8/unsubscribe](https://groups.google.com/d/topic/cesium-dev/uFjOz5F0uK8/unsubscribe).
> > > > > > 
> > > > > > To unsubscribe from this group and all its topics, send an email to [cesium-dev+...@googlegroups.com](mailto:cesium-dev+...@googlegroups.com).
> > > > > > 
> > > > > > For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout).

> > > > >

> > > > > –  
> > > > > [twitter.com/pjcozzi](http://twitter.com/pjcozzi)

> > > –
> > > 
> > > You received this message because you are subscribed to a topic in the Google Groups “cesium-dev” group.
> > > 
> > > To unsubscribe from this topic, visit [https://groups.google.com/d/topic/cesium-dev/uFjOz5F0uK8/unsubscribe](https://groups.google.com/d/topic/cesium-dev/uFjOz5F0uK8/unsubscribe).
> > > 
> > > To unsubscribe from this group and all its topics, send an email to [cesium-dev+unsubscribe@googlegroups.com](mailto:cesium-dev+unsubscribe@googlegroups.com).
> > > 
> > > For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout).

> >

> > –  
> > [twitter.com/pjcozzi](http://twitter.com/pjcozzi)

> > –
> > 
> > You received this message because you are subscribed to a topic in the Google Groups “cesium-dev” group.
> > 
> > To unsubscribe from this topic, visit [https://groups.google.com/d/topic/cesium-dev/uFjOz5F0uK8/unsubscribe](https://groups.google.com/d/topic/cesium-dev/uFjOz5F0uK8/unsubscribe).
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> > For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout).

> 

So I ended up creating a custom datasource instead and using that method, only downside is it takes a while to load the json and set all of the sampledpositionproperty, and I still can’t increase the size of the entities once created. My current method is creating an array of Cesium.SampledPositionProperty for each size that I want to be able to increase or decrease to for each entity…and then looping through the entities and setting the positions. So if the method you mentioned [Matrix4.fromScale](https://github.com/AnalyticalGraphicsInc/cesium/blob/master/Source/Core/Matrix4.js#L425) will work please help me understand how! Thank you for your time.

---

<div class="post-metadata">

**Author:** ![David3](https://avatars.discourse-cdn.com/v4/letter/d/f475e1/32.png) [@David3](https://community.cesium.com/u/David3)\
**Post date:** [August 13, 2014, 8:35pm UTC](https://community.cesium.com/t/is-it-possible-to-change-the-length-of-an-existing-cylinder/780/10 "2014-08-13T20:35:01Z")

</div>

But how can you have the primitive redrawn? when I make a change it isn’t reflected. although if I use the same method before the object is drawn it does reflect the change. So my issues isthat the primitive isn’t redrawn after the change, any ideas?

---

<div class="post-metadata">

**Author:** ![patrick](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/patrick/32/2045_2.png) [@patrick](https://community.cesium.com/u/patrick)\
**Post date:** [August 18, 2014, 1:01pm UTC](https://community.cesium.com/t/is-it-possible-to-change-the-length-of-an-existing-cylinder/780/11 "2014-08-18T13:01:00Z")

</div>

Can you provide a concise code example? The scene is automatically redrawn unless you explicitly set viewer.useDefaultRenderLoop to false. In Cesium 1.0, in 3D, if a primitive contains a single geometry, we should be able to update its modelMatrix and it should be reflected in the next frame.

Patrick

---

<div class="post-metadata">

**Author:** ![David3](https://avatars.discourse-cdn.com/v4/letter/d/f475e1/32.png) [@David3](https://community.cesium.com/u/David3)\
**Post date:** [August 18, 2014, 3:44pm UTC](https://community.cesium.com/t/is-it-possible-to-change-the-length-of-an-existing-cylinder/780/12 "2014-08-18T15:44:27Z")

</div>

here is a sandcastle code example that has 2 problems

1. object isn’t redrawn after modelmatrix is changed(to see if the code does anything change addToolbarButton to addDefaultToolbarButton this will process the code before its drawn)

2. Changing the model matrix moves location of the model instead of changing its dimensions, i want to keep its position but change its height or rather make it taller.

var viewer = new Cesium.Viewer(‘cesiumContainer’, {

```
            sceneMode: Cesium.SceneMode.COLUMBUS_VIEW,

            //Hide the base layer picker

            baseLayerPicker: false,

            //Use BingMaps

            imageryProvider: new Cesium.BingMapsImageryProvider({

                url: '//dev.virtualearth.net',

                mapStyle: Cesium.BingMapsStyle.ROAD

            }),

            fullscreenButton: false,

            homeButton: false,

            navigationHelpButton: false,

            navigationInstructionsInitiallyVisible: false,

            animation: false,

            geocoder: false,

            infobox: false,

            sceneModePicker: false,

            selectionIndicator: false,

            timeline: false

        });

```

var scene = viewer.scene;

var toolbar = document.getElementById(‘toolbar’);

var primitives = viewer.scene.primitives;

// Draw a red box and position it on the globe surface.

var dimensions = new Cesium.Cartesian3(50.0, 50.0, 1000.0);

// Box geometries are initially centered on the origin.

// We can use a model matrix to position the box on the

// globe surface.

var positionOnEllipsoid = Cesium.Cartesian3.fromDegrees(-111, 41);

var boxModelMatrix = Cesium.Matrix4.multiplyByTranslation(

```
Cesium.Transforms.eastNorthUpToFixedFrame(positionOnEllipsoid),

new Cesium.Cartesian3(0.0, 0.0, dimensions.z * 0.5), new Cesium.Matrix4());

```

// Create a box geometry.

var boxGeometry = Cesium.BoxGeometry.fromDimensions({

```
vertexFormat : Cesium.PerInstanceColorAppearance.VERTEX_FORMAT,

dimensions : dimensions

```

});

// Create a geometry instance using the geometry

// and model matrix created above.

var boxGeometryInstance = new Cesium.GeometryInstance({

```
geometry : boxGeometry,

modelMatrix : boxModelMatrix,

attributes : {

    color : Cesium.ColorGeometryInstanceAttribute.fromColor(new Cesium.Color(1.0, 0.0, 0.0, 0.5))

}

```

});

// Add the geometry instance to primitives.

primitives.add(new Cesium.Primitive({

```
releaseGeometryInstances : false,

asynchronous : false,

geometryInstances : boxGeometryInstance,

appearance : new Cesium.PerInstanceColorAppearance({

    closed: true

})

```

}));

viewer.scene.camera.flyTo({

```
                    destination: Cesium.Cartesian3.fromDegrees(-111 - .006, 41 - .05, 5000.0),

                    up: new Cesium.Cartesian3(0.0, 0.0, 1),

                    direction: new Cesium.Cartesian3(0.3, 0.5, -.5)

                });

```

Sandcastle.addToolbarButton(‘Change Model Matrix’, function() {

```
var prim = viewer.scene.primitives.get(0);

alert(prim);//check to see if primitive object exists

var matrix = prim.geometryInstances.modelMatrix;

alert(matrix);//check to see if the matrix object exists

var newMatrix = Cesium.Matrix4.multiplyByTranslation(

Cesium.Transforms.eastNorthUpToFixedFrame(positionOnEllipsoid),

new Cesium.Cartesian3(0.0, 0.0, dimensions.z), new Cesium.Matrix4());

prim.geometryInstances.modelMatrix = newMatrix;

```

});

``

---

<div class="post-metadata">

**Author:** ![David3](https://avatars.discourse-cdn.com/v4/letter/d/f475e1/32.png) [@David3](https://community.cesium.com/u/David3)\
**Post date:** [August 20, 2014, 9:04pm UTC](https://community.cesium.com/t/is-it-possible-to-change-the-length-of-an-existing-cylinder/780/13 "2014-08-20T21:04:49Z")

</div>

I was able to figure out that it is possible to change the height width color and much more of a polygon contained in a czmldatasource here are the functions i’ve created

function changePolygonHeight(layer, height) {

var datasource = viewer.dataSources.get(layer);

datasource.entities.suspendEvents();

var entities = viewer.dataSources.get(layer).entities.entities

for (var i = 0; i \< entities.length; i++) {

var extrudedHeights = source.entities.entities[i].\_polygon.\_extrudedHeight.\_values;

for (var j = 0; j \< extrudedHeights.length; j++) {

var extrudedHeight = source.entities.entities[i].\_polygon.\_extrudedHeight.\_values[j].data;

extrudedHeight = extrudedHeight \* 2;

}

}

datasource.entities.resumeEvents();

}

function changePolygonWidth(layer, width){

var datasource = viewer.dataSources.get(layer);

datasource.entities.suspendEvents();

var entities = viewer.dataSources.get(layer).entities.entities

for (var i = 0; i \< entities.length; i++) {

var lat = entities[i].lat;

var long = entities[i].long;

var positions = entities[i].\_polygon.\_positions;

positions.setValue(Cesium.Cartesian3.fromDegreesArray(degreesToFourPoints(lat,long)));

}

}

function changePolygonColor(layer, red, green, blue) {

var datasource = viewer.dataSources.get(layer);

datasource.entities.suspendEvents();

var entities = viewer.dataSources.get(layer).entities.entities

for (var i = 0; i \< entities.length; i++) {

entities[i].\_polygon.\_material.\_color.setValue(Color.fromBytes(red,green,blue,255));

}

}

function degreesToFourPoints(lattitude, longitude) { // generate four points at an equal distance from the center point

var ax,ay,az,bx,by,bz,cx,cy,cz,dx,dy,dz;

ax = longitude+.001;

ay = lattitude+.001;

az = 0.0;

bx = longitude-.001;

by = lattitude+.001;

bz = 0.0;

cx = longitude-.001;

cy = lattitude-.001;

cz = 0.0;

dx = longitude+.001;

dy = lattitude-.001;

dz = 0.0;

var points = [ax,ay,az,bx,by,bz,cx,cy,cz,dx,dy,dz];

return points;

}

``

---

<div class="post-metadata">

**Author:** ![David3](https://avatars.discourse-cdn.com/v4/letter/d/f475e1/32.png) [@David3](https://community.cesium.com/u/David3)\
**Post date:** [August 20, 2014, 9:05pm UTC](https://community.cesium.com/t/is-it-possible-to-change-the-length-of-an-existing-cylinder/780/14 "2014-08-20T21:05:57Z")

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I forgot to add the resumeEvents() to some of those…