Model

new Model()

A 3D model based on glTF, the runtime asset format for WebGL, OpenGL ES, and OpenGL.

Cesium includes support for geometry and materials, glTF animations, and glTF skinning. In addition, individual glTF nodes are pickable with Scene#pick and animatable with Model#getNode. glTF cameras and lights are not currently supported.

An external glTF asset is created with Model.fromGltf. glTF JSON can also be created at runtime and passed to this constructor function. In either case, the Model#readyToRender event is fired when the model is ready to render, i.e., when the external binary, image, and shader files are downloaded and the WebGL resources are created.

Name Type Default Description
options.gltf Object optional The object for the glTF JSON.
options.basePath String '' optional The base path that paths in the glTF JSON are relative to.
options.show Boolean true optional Determines if the model primitive will be shown.
options.modelMatrix Matrix4 Matrix4.IDENTITY optional The 4x4 transformation matrix that transforms the model from model to world coordinates.
options.scale Number 1.0 optional A uniform scale applied to this model.
options.minimumPixelSize Number 0.0 optional The approximate minimum pixel size of the model regardless of zoom.
options.id Object optional A user-defined object to return when the model is picked with Scene#pick.
options.allowPicking Boolean true optional When true, each glTF mesh and primitive is pickable with Scene#pick.
options.asynchronous Boolean true optional Determines if model WebGL resource creation will be spread out over several frames or block until completion once all glTF files are loaded.
options.debugShowBoundingVolume Boolean false optional For debugging only. Draws the bounding sphere for each DrawCommand in the model.
options.debugWireframe Boolean false optional For debugging only. Draws the model in wireframe.
See:

Members

activeAnimations :ModelAnimationCollection

The currently playing glTF animations.

readonlyallowPicking :Boolean

When true, each glTF mesh and primitive is pickable with Scene#pick. When false, GPU memory is saved.
Default Value: true

readonlyasynchronous :Boolean

Determines if model WebGL resource creation will be spread out over several frames or block until completion once all glTF files are loaded.
Default Value: true

readonlybasePath :String

The base path that paths in the glTF JSON are relative to. The base path is the same path as the path containing the .json file minus the .json file, when binary, image, and shader files are in the same directory as the .json. When this is '', the app's base path is used.
Default Value: ''

readonlyboundingSphere :DeveloperError

The model's bounding sphere in its local coordinate system. This does not take into account glTF animation and skins or Model#scale.
Default Value: undefined
Example:
// Center in WGS84 coordinates
var center = Matrix4.multiplyByPoint(model.modelMatrix, model.boundingSphere.center);

debugShowBoundingVolume :Boolean

This property is for debugging only; it is not for production use nor is it optimized.

Draws the bounding sphere for each DrawCommand in the model. A glTF primitive corresponds to one DrawCommand. A glTF mesh has an array of primitives, often of length one.

Default Value: false

debugWireframe :Boolean

This property is for debugging only; it is not for production use nor is it optimized.

Draws the model in wireframe.

Default Value: false

readonlygltf :Object

The object for the glTF JSON, including properties with default values omitted from the JSON provided to this model.
Default Value: undefined

id :Object

User-defined object returned when the model is picked.
Default Value: undefined
See:

minimumPixelSize :Number

The approximate minimum pixel size of the model regardless of zoom. This can be used to ensure that a model is visible even when the viewer zooms out. When 0.0, no minimum size is enforced.
Default Value: 0.0

modelMatrix :Matrix4

The 4x4 transformation matrix that transforms the model from model to world coordinates. When this is the identity matrix, the model is 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.IDENTITY
Example:
var origin = Cesium.Cartesian3.fromDegrees(-95.0, 40.0, 200000.0);
m.modelMatrix = Transforms.eastNorthUpToFixedFrame(origin);
See:

readonlyready :Boolean

When true, this model is ready to render, i.e., the external binary, image, and shader files were downloaded and the WebGL resources were created. This is set to true right before Model#readyToRender is fired.
Default Value: false
See:

readyToRender :Event

The event fired when this model is ready to render, i.e., when the external binary, image, and shader files were downloaded and the WebGL resources were created.

This event is fired at the end of the frame before the first frame the model is rendered in.

Default Value: new Event()
Example:
// Play all animations at half-speed when the model is ready to render
model.readyToRender.addEventListener(function(model) {
  model.activeAnimations.addAll({
    speedup : 0.5
  });
});
See:

scale :Number

A uniform scale applied to this model before the Model#modelMatrix. Values greater than 1.0 increase the size of the model; values less than 1.0 decrease.
Default Value: 1.0

show :Boolean

Determines if the model primitive will be shown.
Default Value: true

Methods

staticModel.fromGltf()Model

Creates a model from a glTF asset. When the model is ready to render, i.e., when the external binary, image, and shader files are downloaded and the WebGL resources are created, the Model#readyToRender event is fired.
Name Type Default Description
options.url String The url to the glTF .json file.
options.headers Object optional HTTP headers to send with the request.
options.show Boolean true optional Determines if the model primitive will be shown.
options.modelMatrix Matrix4 Matrix4.IDENTITY optional The 4x4 transformation matrix that transforms the model from model to world coordinates.
options.scale Number 1.0 optional A uniform scale applied to this model.
options.minimumPixelSize Number 0.0 optional The approximate minimum pixel size of the model regardless of zoom.
options.allowPicking Boolean true optional When true, each glTF mesh and primitive is pickable with Scene#pick.
options.asynchronous Boolean true optional Determines if model WebGL resource creation will be spread out over several frames or block until completion once all glTF files are loaded.
options.debugShowBoundingVolume Boolean false optional For debugging only. Draws the bounding sphere for each DrawCommand in the model.
options.debugWireframe Boolean false optional For debugging only. Draws the model in wireframe.
Returns:
The newly created model.
Example:
// Example 1. Create a model from a glTF asset
var model = scene.primitives.add(Model.fromGltf({
  url : './duck/duck.json'
}));

// Example 2. Create model and provide all properties and events
var origin = Cesium.Cartesian3.fromDegrees(-95.0, 40.0, 200000.0);
var modelMatrix = Transforms.eastNorthUpToFixedFrame(origin);

var model = scene.primitives.add(Model.fromGltf({
  url : './duck/duck.json',
  show : true,                     // default
  modelMatrix : modelMatrix,
  scale : 2.0,                     // double size
  minimumPixelSize : 128,          // never smaller than 128 pixels
  allowPicking : false,            // not pickable
  debugShowBoundingVolume : false, // default
  debugWireframe : false
}));

model.readyToRender.addEventListener(function(model) {
  // Play all animations when the model is ready to render
  model.activeAnimations.addAll();
});
See:

destroy()undefined

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 isDestroyed will result in a DeveloperError exception. Therefore, assign the return value (undefined) to the object as done in the example.
Returns:
Throws:
  • DeveloperError : This object was destroyed, i.e., destroy() was called.
Example:
model = model && model.destroy();
See:

getMaterial(name)ModelMaterial

Returns the glTF material with the given name property.
Name Type Description
name String The glTF name of the material.
Returns:
The material or undefined if no material with name exists.
Throws:
  • DeveloperError : The model is not loaded. Wait for the model's readyToRender event or ready property.

getMesh(name)ModelMesh

Returns the glTF mesh with the given name property.
Name Type Description
name String The glTF name of the mesh.
Returns:
The mesh or undefined if no mesh with name exists.
Throws:
  • DeveloperError : The model is not loaded. Wait for the model's readyToRender event or ready property.

getNode(name)ModelNode

Returns the glTF node with the given name property. This is used to modify a node's transform for animation outside of glTF animations.
Name Type Description
name String The glTF name of the node.
Returns:
The node or undefined if no node with name exists.
Throws:
  • DeveloperError : The model is not loaded. Wait for the model's readyToRender event or ready property.
Example:
// Apply non-uniform scale to node LOD3sp
var node = model.getNode('LOD3sp');
node.matrix = Matrix4.fromScale(new Cartesian3(5.0, 1.0, 1.0), node.matrix);

isDestroyed()Boolean

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: