Model

internal constructor new Cesium.Model()
engine/Source/Scene/Model/Model.js 163

To construct a Model, call Model.fromGltfAsync. Do not call the constructor directly.
A 3D model based on glTF, the runtime asset format for WebGL, OpenGL ES, and OpenGL.

Cesium supports glTF assets with the following extensions:

Note: for models with compressed textures using the KHR_texture_basisu extension, we recommend power of 2 textures in both dimensions for maximum compatibility. This is because some samplers require power of 2 textures (Using textures in WebGL) and KHR_texture_basisu requires multiple of 4 dimensions (KHR_texture_basisu additional requirements).

Demo:
See:

Members

readonly activeAnimations : ModelAnimationCollection
engine/Source/Scene/Model/Model.js 688

The currently playing glTF animations.

backFaceCulling : boolean
engine/Source/Scene/Model/Model.js 1364

Whether to cull back-facing geometry. When true, back face culling is determined by the material's doubleSided property; when false, back face culling is disabled. Back faces are not culled if Model#color is translucent or Model#silhouetteSize is greater than 0.0.
Default Value: true

readonly boundingSphere : BoundingSphere
engine/Source/Scene/Model/Model.js 1099

Gets the model's bounding sphere in world space. This does not take into account glTF animations, skins, or morph targets. It also does not account for Model#minimumPixelSize.

clampAnimations : boolean
engine/Source/Scene/Model/Model.js 702

Determines if the model's animations should hold a pose over frames where no keyframes are specified.
Default Value: true

readonly classificationType : ClassificationType
engine/Source/Scene/Model/Model.js 1564

Gets the model's classification type. This determines whether terrain, 3D Tiles, or both will be classified by this model.

Additionally, there are a few requirements/limitations:

  • The glTF cannot contain morph targets, skins, or animations.
  • The glTF cannot contain the EXT_mesh_gpu_instancing extension.
  • Only meshes with TRIANGLES can be used to classify other assets.
  • The position attribute is required.
  • If feature IDs and an index buffer are both present, all indices with the same feature id must occupy contiguous sections of the index buffer.
  • If feature IDs are present without an index buffer, all positions with the same feature id must occupy contiguous sections of the position buffer.

Default Value: undefined
Experimental

This feature is using part of the 3D Tiles spec that is not final and is subject to change without Cesium's standard deprecation policy.

clippingPlanes : ClippingPlaneCollection
engine/Source/Scene/Model/Model.js 1283

The ClippingPlaneCollection used to selectively disable rendering the model.

color : Color
engine/Source/Scene/Model/Model.js 988

The color to blend with the model's rendered color.
Default Value: undefined

colorBlendAmount : number
engine/Source/Scene/Model/Model.js 1027

Value used to determine the color strength when the colorBlendMode is MIX. A value of 0.0 results in the model's rendered color while a value of 1.0 results in a solid color, with any value in-between resulting in a mix of the two.
Default Value: 0.5

colorBlendMode : Cesium3DTileColorBlendMode|ColorBlendMode
engine/Source/Scene/Model/Model.js 1009

Defines how the color blends with the model.
Default Value: ColorBlendMode.HIGHLIGHT

readonly credit : Credit
engine/Source/Scene/Model/Model.js 1491

Gets the credit that will be displayed for the model.

customShader : CustomShader
engine/Source/Scene/Model/Model.js 777

The model's custom shader, if it exists. Using custom shaders with a Cesium3DTileStyle may lead to undefined behavior.
Experimental

This feature is using part of the 3D Tiles spec that is not final and is subject to change without Cesium's standard deprecation policy.

debugShowBoundingVolume : boolean
engine/Source/Scene/Model/Model.js 1130

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 model.

Default Value: false

debugWireframe : boolean
engine/Source/Scene/Model/Model.js 1154

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

Draws the model in wireframe.

Default Value: false

distanceDisplayCondition : DistanceDisplayCondition
engine/Source/Scene/Model/Model.js 852

Gets or sets the distance display condition, which specifies at what distance from the camera this model will be displayed.
Default Value: undefined

readonly errorEvent : Event
engine/Source/Scene/Model/Model.js 600

Gets an event that is raised when the model encounters an asynchronous rendering error. By subscribing to the event, you will be notified of the error and can potentially recover from it. Event listeners are passed an instance of ModelError.

featureIdLabel : string
engine/Source/Scene/Model/Model.js 1218

Label of the feature ID set to use for picking and styling.

For EXT_mesh_features, this is the feature ID's label property, or "featureId_N" (where N is the index in the featureIds array) when not specified. EXT_feature_metadata did not have a label field, so such feature ID sets are always labeled "featureId_N" where N is the index in the list of all feature Ids, where feature ID attributes are listed before feature ID textures.

If featureIdLabel is set to an integer N, it is converted to the string "featureId_N" automatically. If both per-primitive and per-instance feature IDs are present, the instance feature IDs take priority.

Experimental

This feature is using part of the 3D Tiles spec that is not final and is subject to change without Cesium's standard deprecation policy.

heightReference : HeightReference
engine/Source/Scene/Model/Model.js 829

The height reference of the model, which determines how the model is drawn relative to terrain.
Default Value: {HeightReference.NONE}

id : object
engine/Source/Scene/Model/Model.js 933

A user-defined object that is returned when the model is picked.
Default Value: undefined
See:

imageBasedLighting : ImageBasedLighting
engine/Source/Scene/Model/Model.js 1329

The properties for managing image-based lighting on this model.

instanceFeatureIdLabel : string
engine/Source/Scene/Model/Model.js 1254

Label of the instance feature ID set used for picking and styling.

If instanceFeatureIdLabel is set to an integer N, it is converted to the string "instanceFeatureId_N" automatically. If both per-primitive and per-instance feature IDs are present, the instance feature IDs take priority.

Experimental

This feature is using part of the 3D Tiles spec that is not final and is subject to change without Cesium's standard deprecation policy.

lightColor : Cartesian3
engine/Source/Scene/Model/Model.js 1309

The light color when shading the model. When undefined the scene's light color is used instead.

Disabling additional light sources by setting model.imageBasedLighting.imageBasedLightingFactor = new Cartesian2(0.0, 0.0) will make the model much darker. Here, increasing the intensity of the light source will make the model brighter.

Default Value: undefined

maximumScale : number
engine/Source/Scene/Model/Model.js 1449

The maximum scale size for a model. This can be used to give an upper limit to the Model#minimumPixelSize, ensuring that the model is never an unreasonable scale.

minimumPixelSize : number
engine/Source/Scene/Model/Model.js 1428

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
engine/Source/Scene/Model/Model.js 204

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 Cartesian 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:
const origin = Cesium.Cartesian3.fromDegrees(-95.0, 40.0, 200000.0);
m.modelMatrix = Cesium.Transforms.eastNorthUpToFixedFrame(origin);

outlineColor : Color
engine/Source/Scene/Model/Model.js 447

The color to use when rendering outlines.
Default Value: Color.BLACK

pointCloudShading : PointCloudShading
engine/Source/Scene/Model/Model.js 753

Point cloud shading settings for controlling point cloud attenuation and lighting. For 3D Tiles, this is inherited from the Cesium3DTileset.

readonly ready : boolean
engine/Source/Scene/Model/Model.js 586

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.
Default Value: false

readonly readyEvent : Event
engine/Source/Scene/Model/Model.js 619

Gets an event that is raised when the model is loaded and ready for rendering, i.e. when the external resources have been downloaded and the WebGL resources are created. Event listeners are passed an instance of the Model.

If Model.incrementallyLoadTextures is true, this event will be raised before all textures are loaded and ready for rendering. Subscribe to Model.texturesReadyEvent to be notified when the textures are ready.

scale : number
engine/Source/Scene/Model/Model.js 1388

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

shadows : ShadowMode
engine/Source/Scene/Model/Model.js 1470

Determines whether the model casts or receives shadows from light sources.
Default Value: ShadowMode.ENABLED

show : boolean
engine/Source/Scene/Model/Model.js 1187

Whether or not to render the model.
Default Value: true

showCreditsOnScreen : boolean
engine/Source/Scene/Model/Model.js 1507

Gets or sets whether the credits of the model will be displayed on the screen.
Default Value: false

showOutline : boolean
engine/Source/Scene/Model/Model.js 438

Whether to display the outline for models using the CESIUM_primitive_outline extension. When true, outlines are displayed. When false, outlines are not displayed.
Default Value: true

silhouetteColor : Color
engine/Source/Scene/Model/Model.js 1045

The silhouette color.
Default Value: Color.RED

silhouetteSize : number
engine/Source/Scene/Model/Model.js 1068

The size of the silhouette in pixels.
Default Value: 0.0

splitDirection : SplitDirection
engine/Source/Scene/Model/Model.js 1529

The SplitDirection to apply to this model.
Default Value: SplitDirection.NONE

style : Cesium3DTileStyle
engine/Source/Scene/Model/Model.js 969

The style to apply to the features in the model. Cannot be applied if a CustomShader is also applied.

readonly texturesReadyEvent : Event
engine/Source/Scene/Model/Model.js 649

Gets an event that, if Model.incrementallyLoadTextures is true, is raised when the model textures are loaded and ready for rendering, i.e. when the external resources have been downloaded and the WebGL resources are created. Event listeners are passed an instance of the Model.

Methods

static Cesium.Model.fromGltfAsync(options) → Promise.<Model>
engine/Source/Scene/Model/Model.js 2722

Asynchronously creates a model from a glTF asset. This function returns a promise that resolves 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 can be a traditional glTF asset with a .gltf extension or a Binary glTF using the .glb extension.

Name Type Description
options object Object with the following properties:
Name Type Default Description
url string | Resource The url to the .gltf or .glb file.
basePath string | Resource '' optional The base path that paths in the glTF JSON are relative to.
show boolean true optional Whether or not to render the model.
modelMatrix Matrix4 Matrix4.IDENTITY optional The 4x4 transformation matrix that transforms the model from model to world coordinates.
scale number 1.0 optional A uniform scale applied to this model.
minimumPixelSize number 0.0 optional The approximate minimum pixel size of the model regardless of zoom.
maximumScale number optional The maximum scale size of a model. An upper limit for minimumPixelSize.
id object optional A user-defined object to return when the model is picked with Scene#pick.
allowPicking boolean true optional When true, each primitive is pickable with Scene#pick.
incrementallyLoadTextures boolean true optional Determine if textures may continue to stream in after the model is loaded.
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.
clampAnimations boolean true optional Determines if the model's animations should hold a pose over frames where no keyframes are specified.
shadows ShadowMode ShadowMode.ENABLED optional Determines whether the model casts or receives shadows from light sources.
releaseGltfJson boolean false optional When true, the glTF JSON is released once the glTF is loaded. This is is especially useful for cases like 3D Tiles, where each .gltf model is unique and caching the glTF JSON is not effective.
debugShowBoundingVolume boolean false optional For debugging only. Draws the bounding sphere for each draw command in the model.
enableDebugWireframe boolean false optional For debugging only. This must be set to true for debugWireframe to work in WebGL1. This cannot be set after the model has loaded.
debugWireframe boolean false optional For debugging only. Draws the model in wireframe. Will only work for WebGL1 if enableDebugWireframe is set to true.
cull boolean true optional Whether or not to cull the model using frustum/horizon culling. If the model is part of a 3D Tiles tileset, this property will always be false, since the 3D Tiles culling system is used.
opaquePass boolean Pass.OPAQUE optional The pass to use in the DrawCommand for the opaque portions of the model.
upAxis Axis Axis.Y optional The up-axis of the glTF model.
forwardAxis Axis Axis.Z optional The forward-axis of the glTF model.
customShader CustomShader optional A custom shader. This will add user-defined GLSL code to the vertex and fragment shaders. Using custom shaders with a Cesium3DTileStyle may lead to undefined behavior.
content Cesium3DTileContent optional The tile content this model belongs to. This property will be undefined if model is not loaded as part of a tileset.
heightReference HeightReference HeightReference.NONE optional Determines how the model is drawn relative to terrain.
scene Scene optional Must be passed in for models that use the height reference property.
distanceDisplayCondition DistanceDisplayCondition optional The condition specifying at what distance from the camera that this model will be displayed.
color Color optional A color that blends with the model's rendered color.
colorBlendMode ColorBlendMode ColorBlendMode.HIGHLIGHT optional Defines how the color blends with the model.
colorBlendAmount number 0.5 optional Value used to determine the color strength when the colorBlendMode is MIX. A value of 0.0 results in the model's rendered color while a value of 1.0 results in a solid color, with any value in-between resulting in a mix of the two.
silhouetteColor Color Color.RED optional The silhouette color. If more than 256 models have silhouettes enabled, there is a small chance that overlapping models will have minor artifacts.
silhouetteSize number 0.0 optional The size of the silhouette in pixels.
enableShowOutline boolean true optional Whether to enable outlines for models using the CESIUM_primitive_outline extension. This can be set false to avoid post-processing geometry at load time. When false, the showOutlines and outlineColor options are ignored.
showOutline boolean true optional Whether to display the outline for models using the CESIUM_primitive_outline extension. When true, outlines are displayed. When false, outlines are not displayed.
outlineColor Color Color.BLACK optional The color to use when rendering outlines.
clippingPlanes ClippingPlaneCollection optional The ClippingPlaneCollection used to selectively disable rendering the model.
lightColor Cartesian3 optional The light color when shading the model. When undefined the scene's light color is used instead.
imageBasedLighting ImageBasedLighting optional The properties for managing image-based lighting on this model.
backFaceCulling boolean true optional Whether to cull back-facing geometry. When true, back face culling is determined by the material's doubleSided property; when false, back face culling is disabled. Back faces are not culled if the model's color is translucent.
credit Credit | string optional A credit for the data source, which is displayed on the canvas.
showCreditsOnScreen boolean false optional Whether to display the credits of this model on screen.
splitDirection SplitDirection SplitDirection.NONE optional The SplitDirection split to apply to this model.
projectTo2D boolean false optional Whether to accurately project the model's positions in 2D. If this is true, the model will be projected accurately to 2D, but it will use more memory to do so. If this is false, the model will use less memory and will still render in 2D / CV mode, but its positions may be inaccurate. This disables minimumPixelSize and prevents future modification to the model matrix. This also cannot be set after the model has loaded.
featureIdLabel string | number "featureId_0" optional Label of the feature ID set to use for picking and styling. For EXT_mesh_features, this is the feature ID's label property, or "featureId_N" (where N is the index in the featureIds array) when not specified. EXT_feature_metadata did not have a label field, so such feature ID sets are always labeled "featureId_N" where N is the index in the list of all feature Ids, where feature ID attributes are listed before feature ID textures. If featureIdLabel is an integer N, it is converted to the string "featureId_N" automatically. If both per-primitive and per-instance feature IDs are present, the instance feature IDs take priority.
instanceFeatureIdLabel string | number "instanceFeatureId_0" optional Label of the instance feature ID set used for picking and styling. If instanceFeatureIdLabel is set to an integer N, it is converted to the string "instanceFeatureId_N" automatically. If both per-primitive and per-instance feature IDs are present, the instance feature IDs take priority.
pointCloudShading object optional Options for constructing a PointCloudShading object to control point attenuation and lighting.
classificationType ClassificationType optional Determines whether terrain, 3D Tiles or both will be classified by this model. This cannot be set after the model has loaded.
gltfCallback Model.GltfCallback optional A function that is called with the loaded gltf object once loaded.
Returns:
A promise that resolves to the created model when it is ready to render.
Throws:
Examples:
// Load a model and add it to the scene
try {
 const model = await Cesium.Model.fromGltfAsync({
   url: "../../SampleData/models/CesiumMan/Cesium_Man.glb"
 });
 viewer.scene.primitives.add(model);
} catch (error) {
 console.log(`Failed to load model. ${error}`);
}
// Position a model with modelMatrix and display it with a minimum size of 128 pixels
const position = Cesium.Cartesian3.fromDegrees(
  -123.0744619,
  44.0503706,
  5000.0
);
const headingPositionRoll = new Cesium.HeadingPitchRoll();
const fixedFrameTransform = Cesium.Transforms.localFrameToFixedFrameGenerator(
  "north",
  "west"
);
try {
 const model = await Cesium.Model.fromGltfAsync({
   url: "../../SampleData/models/CesiumAir/Cesium_Air.glb",
   modelMatrix: Cesium.Transforms.headingPitchRollToFixedFrame(
     position,
     headingPositionRoll,
     Cesium.Ellipsoid.WGS84,
     fixedFrameTransform
   ),
   minimumPixelSize: 128,
 });
 viewer.scene.primitives.add(model);
} catch (error) {
 console.log(`Failed to load model. ${error}`);
}
// Load a model and play the last animation at half speed
let animations;
try {
 const model = await Cesium.Model.fromGltfAsync({
   url: "../../SampleData/models/CesiumMan/Cesium_Man.glb",
   gltfCallback: gltf => {
     animations = gltf.animations
   }
 });
 viewer.scene.primitives.add(model);
 model.readyEvent.addEventListener(() => {
   model.activeAnimations.add({
     index: animations.length - 1,
     loop: Cesium.ModelAnimationLoop.REPEAT,
     multiplier: 0.5,
   });
 });
} catch (error) {
 console.log(`Failed to load model. ${error}`);
}

applyArticulations()
engine/Source/Scene/Model/Model.js 1669

Applies any modified articulation stages to the matrix of each node that participates in any articulation. Note that this will overwrite any node transformations on participating nodes.
Throws:
  • DeveloperError : The model is not loaded. Use Model.readyEvent or wait for Model.ready to be true.

destroy()
engine/Source/Scene/Model/Model.js 2520

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.
Throws:
  • DeveloperError : This object was destroyed, i.e., destroy() was called.
Example:
model = model && model.destroy();
See:

getNode(name) → ModelNode
engine/Source/Scene/Model/Model.js 1620

Returns the node with the given name in the glTF. This is used to modify a node's transform for user-defined animation.
Name Type Description
name string The name of the node in the glTF.
Returns:
The node, or undefined if no node with the name exists.
Throws:
  • DeveloperError : The model is not loaded. Use Model.readyEvent or wait for Model.ready to be true.
Example:
// Apply non-uniform scale to node "Hand"
const node = model.getNode("Hand");
node.matrix = Cesium.Matrix4.fromScale(new Cesium.Cartesian3(5.0, 1.0, 1.0), node.matrix);

isDestroyed() → boolean
engine/Source/Scene/Model/Model.js 2500

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:

makeStyleDirty()
engine/Source/Scene/Model/Model.js 1685

Marks the model's Model#style as dirty, which forces all features to re-evaluate the style in the next frame the model is visible.

setArticulationStage(articulationStageKey, value)
engine/Source/Scene/Model/Model.js 1649

Sets the current value of an articulation stage. After setting one or multiple stage values, call Model.applyArticulations() to cause the node matrices to be recalculated.
Name Type Description
articulationStageKey string The name of the articulation, a space, and the name of the stage.
value number The numeric value of this stage of the articulation.
Throws:
  • DeveloperError : The model is not loaded. Use Model.readyEvent or wait for Model.ready to be true.
Example:
// Sets the value of the stage named "MoveX" belonging to the articulation named "SampleArticulation"
model.setArticulationStage("SampleArticulation MoveX", 50.0);
See:

update()
engine/Source/Scene/Model/Model.js 1712

Called when Viewer or CesiumWidget render the scene to get the draw commands needed to render this primitive.

Do not call this function directly. This is documented just to list the exceptions that may be propagated when the scene is rendered:

Throws:

Type Definitions

Cesium.Model.GltfCallback(gltf)
engine/Source/Scene/Model/Model.js 3015

Interface for the function that is called with the loaded gltf object once loaded.
Name Type Description
gltf object The gltf object
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