English | 简体中文

PrimitiveCollection

new Cesium.PrimitiveCollection(options)

A collection of primitives. This is most often used with Scene#primitives, but PrimitiveCollection is also a primitive itself so collections can be added to collections forming a hierarchy.
Name Type Description
options object optional Object with the following properties:
Name Type Default Description
show boolean true optional Determines if the primitives in the collection will be shown.
destroyPrimitives boolean true optional Determines if primitives in the collection are destroyed when they are removed.
Example:
const billboards = new Cesium.BillboardCollection();
const labels = new Cesium.LabelCollection();

const collection = new Cesium.PrimitiveCollection();
collection.add(billboards);

scene.primitives.add(collection);  // Add collection
scene.primitives.add(labels);      // Add regular primitive

Members

destroyPrimitives : boolean

Determines if primitives in the collection are destroyed when they are removed by PrimitiveCollection#destroy or PrimitiveCollection#remove or implicitly by PrimitiveCollection#removeAll.
Default Value: true
Examples:
// Example 1. Primitives are destroyed by default.
const primitives = new Cesium.PrimitiveCollection();
const labels = primitives.add(new Cesium.LabelCollection());
primitives = primitives.destroy();
const b = labels.isDestroyed(); // true
// Example 2. Do not destroy primitives in a collection.
const primitives = new Cesium.PrimitiveCollection();
primitives.destroyPrimitives = false;
const labels = primitives.add(new Cesium.LabelCollection());
primitives = primitives.destroy();
const b = labels.isDestroyed(); // false
labels = labels.destroy();    // explicitly destroy
Gets the number of primitives in the collection.
An event that is raised when a primitive is added to the collection. Event handlers are passed the primitive that was added.
An event that is raised when a primitive is removed from the collection. Event handlers are passed the primitive that was removed.

Note: Depending on the destroyPrimitives constructor option, the primitive may already be destroyed.

Determines if primitives in this collection will be shown.
Default Value: true

Methods

add(primitive, index)object

Adds a primitive to the collection.
Name Type Description
primitive object The primitive to add.
index number optional The index to add the layer at. If omitted, the primitive will be added at the bottom of all existing primitives.
Returns:
The primitive added to the collection.
Throws:
  • DeveloperError : This object was destroyed, i.e., destroy() was called.
Example:
const billboards = scene.primitives.add(new Cesium.BillboardCollection());

contains(primitive)boolean

Determines if this collection contains a primitive.
Name Type Description
primitive object optional The primitive to check for.
Returns:
true if the primitive is in the collection; false if the primitive is undefined or was not found in the collection.
Throws:
  • DeveloperError : This object was destroyed, i.e., destroy() was called.
See:
Destroys the WebGL resources held by each primitive in this collection. Explicitly destroying this collection allows for deterministic release of WebGL resources, instead of relying on the garbage collector to destroy this collection.

Since destroying a collection destroys all the contained primitives, only destroy a collection when you are sure no other code is still using any of the contained primitives.

Once this collection 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:
primitives = primitives && primitives.destroy();
See:
Returns the primitive in the collection at the specified index.
Name Type Description
index number The zero-based index of the primitive to return.
Returns:
The primitive at the index.
Throws:
  • DeveloperError : This object was destroyed, i.e., destroy() was called.
Example:
// Toggle the show property of every primitive in the collection.
const primitives = scene.primitives;
const length = primitives.length;
for (let i = 0; i < length; ++i) {
  const p = primitives.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 isDestroyed will result in a DeveloperError exception.
Returns:
True if this object was destroyed; otherwise, false.
See:
Lowers a primitive "down one" in the collection. If all primitives in the collection are drawn on the globe surface, this visually moves the primitive down one.
Name Type Description
primitive object optional The primitive to lower.
Throws:
See:
Lowers a primitive to the "bottom" of the collection. If all primitives in the collection are drawn on the globe surface, this visually moves the primitive to the bottom.
Name Type Description
primitive object optional The primitive to lower to the bottom.
Throws:
See:
Raises a primitive "up one" in the collection. If all primitives in the collection are drawn on the globe surface, this visually moves the primitive up one.
Name Type Description
primitive object optional The primitive to raise.
Throws:
See:
Raises a primitive to the "top" of the collection. If all primitives in the collection are drawn on the globe surface, this visually moves the primitive to the top.
Name Type Description
primitive object optional The primitive to raise the top.
Throws:
See:

remove(primitive)boolean

Removes a primitive from the collection.
Name Type Description
primitive object optional The primitive to remove.
Returns:
true if the primitive was removed; false if the primitive is undefined or was not found in the collection.
Throws:
  • DeveloperError : This object was destroyed, i.e., destroy() was called.
Example:
const billboards = scene.primitives.add(new Cesium.BillboardCollection());
scene.primitives.remove(billboards);  // Returns true
See:
Removes all primitives in the collection.
Throws:
  • DeveloperError : This object was destroyed, i.e., destroy() was called.
See:
Need help? The fastest way to get answers is from the community and team on the Cesium Forum.