A renderable collection of points.
Points are added and removed from the collection using
Points are added and removed from the collection using
PointPrimitiveCollection#add
and PointPrimitiveCollection#remove.
Performance:
For best performance, prefer a few collections, each with many points, to many collections with only a few points each. Organize collections so that points with the same update frequency are in the same collection, i.e., points that do not change should be in one collection; points that change every frame should be in another collection; and so on.
| Name | Type | Description | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
options |
object |
optional
Object with the following properties:
|
Example:
// Create a pointPrimitive collection with two points
const points = scene.primitives.add(new Cesium.PointPrimitiveCollection());
points.add({
position : new Cesium.Cartesian3(1.0, 2.0, 3.0),
color : Cesium.Color.YELLOW
});
points.add({
position : new Cesium.Cartesian3(4.0, 5.0, 6.0),
color : Cesium.Color.CYAN
});See:
Members
The point blending option. The default is used for rendering both opaque and translucent points.
However, if either all of the points are completely opaque or all are completely translucent,
setting the technique to BlendOption.OPAQUE or BlendOption.TRANSLUCENT can improve
performance by up to 2x.
-
Default Value:
BlendOption.OPAQUE_AND_TRANSLUCENT
This property is for debugging only; it is not for production use nor is it optimized.
Draws the bounding sphere for each draw command in the primitive.
-
Default Value:
false
Returns the number of points in this collection. This is commonly used with
PointPrimitiveCollection#get to iterate over all the points
in the collection.
modelMatrix : Matrix4
The 4x4 transformation matrix that transforms each point in this collection from model to world coordinates.
When this is the identity matrix, the pointPrimitives are drawn in world coordinates, i.e., Earth's WGS84 coordinates.
Local reference frames can be used by providing a different transformation matrix, like that returned
by
Transforms.eastNorthUpToFixedFrame.
-
Default Value:
Matrix4.IDENTITYExample:
const center = Cesium.Cartesian3.fromDegrees(-75.59777, 40.03883);
pointPrimitives.modelMatrix = Cesium.Transforms.eastNorthUpToFixedFrame(center);
pointPrimitives.add({
color : Cesium.Color.ORANGE,
position : new Cesium.Cartesian3(0.0, 0.0, 0.0) // center
});
pointPrimitives.add({
color : Cesium.Color.YELLOW,
position : new Cesium.Cartesian3(1000000.0, 0.0, 0.0) // east
});
pointPrimitives.add({
color : Cesium.Color.GREEN,
position : new Cesium.Cartesian3(0.0, 1000000.0, 0.0) // north
});
pointPrimitives.add({
color : Cesium.Color.CYAN,
position : new Cesium.Cartesian3(0.0, 0.0, 1000000.0) // up
});See:
Determines if primitives in this collection will be shown.
-
Default Value:
true
Methods
Creates and adds a point with the specified initial properties to the collection.
The added point is returned so it can be modified or removed from the collection later.
Performance:
Calling add is expected constant time. However, the collection's vertex buffer
is rewritten - an O(n) operation that also incurs CPU to GPU overhead. For
best performance, add as many pointPrimitives as possible before calling update.
| Name | Type | Description |
|---|---|---|
options |
object | optional A template describing the point's properties as shown in Example 1. |
Returns:
The point that was added to the collection.
Throws:
-
DeveloperError : This object was destroyed, i.e., destroy() was called.
Examples:
// Example 1: Add a point, specifying all the default values.
const p = pointPrimitives.add({
show : true,
position : Cesium.Cartesian3.ZERO,
pixelSize : 10.0,
color : Cesium.Color.WHITE,
outlineColor : Cesium.Color.TRANSPARENT,
outlineWidth : 0.0,
id : undefined
});// Example 2: Specify only the point's cartographic position.
const p = pointPrimitives.add({
position : Cesium.Cartesian3.fromDegrees(longitude, latitude, height)
});See:
Check whether this collection contains a given point.
| Name | Type | Description |
|---|---|---|
pointPrimitive |
PointPrimitive | optional The point to check for. |
Returns:
true if this collection contains the point, false otherwise.
Destroys the WebGL resources held by this object. Destroying an object allows for deterministic
release of WebGL resources, instead of relying on the garbage collector to destroy this object.
Once an object is destroyed, it should not be used; calling any function other than
Once an object is destroyed, it should not be used; calling any function other than
isDestroyed will result in a DeveloperError exception. Therefore,
assign the return value (undefined) to the object as done in the example.
Throws:
-
DeveloperError : This object was destroyed, i.e., destroy() was called.
Example:
pointPrimitives = pointPrimitives && pointPrimitives.destroy();See:
Returns the point in the collection at the specified index. Indices are zero-based
and increase as points are added. Removing a point shifts all points after
it to the left, changing their indices. This function is commonly used with
PointPrimitiveCollection#length to iterate over all the points
in the collection.
Performance:
Expected constant time. If points were removed from the collection and
PointPrimitiveCollection#update was not called, an implicit O(n)
operation is performed.
| Name | Type | Description |
|---|---|---|
index |
number | The zero-based index of the point. |
Returns:
The point at the specified index.
Throws:
-
DeveloperError : This object was destroyed, i.e., destroy() was called.
Example:
// Toggle the show property of every point in the collection
const len = pointPrimitives.length;
for (let i = 0; i < len; ++i) {
const p = pointPrimitives.get(i);
p.show = !p.show;
}See:
Returns true if this object was destroyed; otherwise, false.
If this object was destroyed, it should not be used; calling any function other than
If this object was destroyed, it should not be used; calling any function other than
isDestroyed will result in a DeveloperError exception.
Returns:
true if this object was destroyed; otherwise, false.
Removes a point from the collection.
Performance:
Calling remove is expected constant time. However, the collection's vertex buffer
is rewritten - an O(n) operation that also incurs CPU to GPU overhead. For
best performance, remove as many points as possible before calling update.
If you intend to temporarily hide a point, it is usually more efficient to call
PointPrimitive#show instead of removing and re-adding the point.
| Name | Type | Description |
|---|---|---|
pointPrimitive |
PointPrimitive | The point to remove. |
Returns:
true if the point was removed; false if the point was not found in the collection.
Throws:
-
DeveloperError : This object was destroyed, i.e., destroy() was called.
Example:
const p = pointPrimitives.add(...);
pointPrimitives.remove(p); // Returns trueSee:
Removes all points from the collection.
Performance:
O(n). It is more efficient to remove all the points
from a collection and then add new ones than to create a new collection entirely.
Throws:
-
DeveloperError : This object was destroyed, i.e., destroy() was called.
Example:
pointPrimitives.add(...);
pointPrimitives.add(...);
pointPrimitives.removeAll();