API Docs for: 1.0.0

CameraFollowAnimation

Extends Component
Module: animation
Parent Module: xeogl

A CameraFollowAnimation makes a Camera dynamically follow a World-space Boundary3D in order to keep it entirely in view.

Overview

Examples

Usage

In the example below, we'll use a CameraFollowAnimation to automatically follow an Entity's World-space Boundary3D with the default Camera. Our CameraFollowAnimation's fit property is set true, which causes it to automatically keep the Boundary3D fitted to the view volume. Although we can orbit the Entity using the CameraControl, we you can't control the distance of the Camera from the Entity because our CameraFollowAnimation automatically controls that distance in order to do the automatic fitting.

// Create a red torus Entity with a Translate modelling transform
// that allows it to move around in World-space
var entity = new xeogl.Entity({
    geometry: new xeogl.TorusGeometry(),
    material: new xeogl.PhongMaterial({
         diffuse: [1, 0.3, 0.3]
    }),
    transform: new xeogl.Translate({
        xyz: [0,0,0]
    })
});

// Create a CameraFollowAnimation that makes the (Scene's default) Camera's Lookat follow the Entity's World-space
// Boundary3D, while keeping the Boundary3D fitted to the view volume. The CameraFollowAnimation
// will jump to each updated Boundary3D extents, and since an update will occur on every frame,
// the effect will be as if we're smoothly flying after the Boundary3D. If the updates occur sporadically,
// then we would probably instead configure it to fly to each update, to keep the animation smooth.
var cameraFollowAnimation = new xeogl.CameraFollowAnimation({
    worldBoundary: entity.worldBoundary,
    fit: true,   // Fit target to view volume
    fitFOV: 35,  // Target will occupy 35 degrees of the field-of-view
    fly: false // Jump to each updated boundary extents
});

// Create a SplineCurve along which we'll animate our Entity
var curve = new xeogl.SplineCurve({
    points: [
        [-10, 0, 0],
        [-5, 15, 0],
        [20, 15, 0],
        [10, 0, 0]
    ]
});

// Bind the Entity Translate to a point on the SplineCurve
curve.on("point", function(point) {
    entity.transform.xyz = point;
});

// Animate the point along the SplineCurve using the Scene clock
curve.scene.on("tick", function(e) {
    curve.t = (e.time - e.startTime) * 0.01;
});

// Allow user control of the Camera with mouse and keyboard
// (zooming will be overridden by the auto-fitting configured on our CameraFollowAnimation)
new xeogl.CameraControl();

Constructor

CameraFollowAnimation

(
  • [scene]
  • [cfg]
)

Parameters:

  • [scene] Scene optional

    Parent Scene - creates this CameraFollowAnimation within xeogl's default Xeogl/scene:property by default.

  • [cfg] optional

    Configs

    • [id] String optional

      Optional ID, unique among all components in the parent Scene, generated automatically when omitted.

    • [meta] optional

      Optional map of user-defined metadata to attach to this CameraFollowAnimation.

    • [camera] Number | String | Camera optional

      ID or instance of a Camera to control. Must be within the same Scene as this CameraFollowAnimation. Defaults to the parent Scene's default instance, camera.

    • [worldBoundary] Number | String | Camera optional

      ID or instance of a Boundary3D to follow. Must be within the same Scene as this CameraFollowAnimation. Defaults to the parent Scene's World-space boundary, worldBoundary.

    • [fly] Boolean optional

      Indicates whether this CameraFollowAnimation will either fly or jump to each updated position of the target worldBoundary.

    • [fit] Boolean optional

      When true, will ensure that this CameraFollowAnimation automatically adjusts the distance between the Camera's Lookat's eye and look to keep the target Boundary3D fitted to the view volume.

    • [fitFOV=45] Number optional

      How much of field-of-view, in degrees, that a target worldBoundary should fill the canvas when fitting to view.

    • [trail] Boolean optional

      When true, will cause this CameraFollowAnimation to point the camera in the direction that it is travelling.

Methods

create

(
  • [cfg]
  • [instanceId]
)

Convenience method for creating a Component within this Component's Scene.

You would typically use this method to conveniently instantiate components that you'd want to share (ie. "instance") among your Entities.

The method is given a component type, configuration and optional instance ID, like so:

var material = myComponent.create({
     type: "xeogl.PhongMaterial",
     diffuse: [1,0,0],
     specular: [1,1,0]
}, "myMaterial");

The first time you call this method for the given type and instanceId, this method will create the PhongMaterial, passing the given attributes to the component's constructor.

If you call this method again, specifying the same type and instanceId, the method will return the same component instance that it returned the first time, and will ignore the new configuration:

var material2 = component.create({ type: "xeogl.PhongMaterial", specular: [1,1,0] }, "myMaterial");

So in this example, our PhongMaterial will continue to have the red specular and diffuse color that we specified the first time.

Each time you call this method with the same type and instanceId, the Scene will internally increment a reference count for the component instance.

Parameters:

  • [cfg] optional

    Configuration for the component instance - only used if this is the first time you are getting the component, ignored when reusing an existing instance.

  • [instanceId] String | Number optional

    Identifies the shared component instance. Note that this is not used as the ID of the component - you can specify the component ID in the cfg parameter.

Returns:

:

destroy

()

Destroys this component.

Fires a destroyed event on this Component.

Automatically disassociates this component from other components, causing them to fall back on any defaults that this component overrode on them.

TODO: describe effect with respect to #create

error

(
  • message
)

Logs an error for this component to the JavaScript console.

The console message will have this format: [ERROR] [<component type> =<component id>: <message>

Also fires the message as an error event on the parent Scene.

Parameters:

  • message String

    The message to log

fire

(
  • event
  • value
  • [forget=false]
)

Fires an event on this component.

Notifies existing subscribers to the event, optionally retains the event to give to any subsequent notifications on the event as they are made.

Parameters:

  • event String

    The event type name

  • value Object

    The event parameters

  • [forget=false] Boolean optional

    When true, does not retain for subsequent subscribers

isType

(
  • type
)
Boolean

Tests if this component is of the given type, or is a subclass of the given type.

The type may be given as either a string or a component constructor.

This method works by walking up the inheritance type chain, which this component provides in property superTypes, returning true as soon as one of the type strings in the chain matches the given type, of false if none match.

Examples:

var myRotate = new xeogl.Rotate({ ... });

myRotate.isType(xeogl.Component); // Returns true for all xeogl components
myRotate.isType("xeogl.Component"); // Returns true for all xeogl components
myRotate.isType(xeogl.Rotate); // Returns true
myRotate.isType(xeogl.Transform); // Returns true
myRotate.isType("xeogl.Transform"); // Returns true
myRotate.isType(xeogl.Entity); // Returns false, because xeogl.Rotate does not (even indirectly) extend xeogl.Entity

Parameters:

  • type String | Function

    Component type to compare with, eg "xeogl.PhongMaterial", or a xeogl component constructor.

Returns:

Boolean:

True if this component is of given type or is subclass of the given type.

log

(
  • message
)

Logs a console debugging message for this component.

The console message will have this format: [LOG] [<component type> <component id>: <message>

Also fires the message as a log event on the parent Scene.

Parameters:

  • message String

    The message to log

off

(
  • handle
)

Cancels an event subscription that was previously made with on or once.

Parameters:

  • handle String

    Publication handle

on

(
  • event
  • callback
  • [scope=this]
)
String

Subscribes to an event on this component.

The callback is be called with this component as scope.

Parameters:

  • event String

    The event

  • callback Function

    Called fired on the event

  • [scope=this] Object optional

    Scope for the callback

Returns:

String:

Handle to the subscription, which may be used to unsubscribe with {@link #off}.

once

(
  • event
  • callback
  • [scope=this]
)

Subscribes to the next occurrence of the given event, then un-subscribes as soon as the event is handled.

This is equivalent to calling on, and then calling off inside the callback function.

Parameters:

  • event String

    Data event to listen to

  • callback Function(data)

    Called when fresh data is available at the event

  • [scope=this] Object optional

    Scope for the callback

warn

(
  • message
)

Logs a warning for this component to the JavaScript console.

The console message will have this format: [WARN] [<component type> =<component id>: <message>

Also fires the message as a warn event on the parent Scene.

Parameters:

  • message String

    The message to log

Properties

camera

Camera

The Camera being controlled by this CameraFollowAnimation.

Must be within the same Scene as this CameraFollowAnimation. Defaults to the parent Scene's default camera when set to a null or undefined value.

Fires a camera event on change.

destroyed

Boolean

True as soon as this Component has been destroyed

fit

Boolean

When true, will ensure that this CameraFollowAnimation always adjusts the distance between the camera's eye and look positions so as to ensure that the worldBoundary is always filling the view volume.

When false, the eye will remain at its current distance from the look position.

Fires a fit event on change.

Default: true

fitFOV

Number

When fit is set, to fit the target worldBoundary in view, this property indicates how much of the total field-of-view, in degrees, that the worldBoundary should fill.

Fires a fitFOV event on change.

Default: 45

fly

Boolean

Indicates whether this CameraFollowAnimation will either fly or jump to each updated position of the target worldBoundary.

Leave this false if the worldBoundary updates continuously, otherwise leave it true if you want the camera to fly smoothly to each updated worldBoundary extents for a less disorientating experience.

Fires a fly event on change.

Default: false

id

String final

Unique ID for this Component within its parent Scene.

isDefault

Boolean

Indicates whether this is one of the Scene's built-in Components.

json

JSON final

JSON object containing the state of this Component.

metadata

Object

Arbitrary, user-defined metadata on this component.

scene

Scene final

The parent Scene that contains this Component.

string

String final

Inherited from Component but overwritten in src/component.js:1055

String containing the serialized JSON state of this Component.

superTypes

Array of String final

An array of strings that indicates the chain of super-types within this component's inheritance hierarchy.

For example, if this component is a Rotate, which extends Transform, which in turn extends Component, then this property will have the value:

["xeogl.Component", "xeogl.Transform"]
                    

Note that the chain is ordered downwards in the hierarchy, ie. from super-class down towards sub-class.

trail

Boolean

When true, will cause this CameraFollowAnimation to point the camera in the direction that it is travelling.

Fires a trail event on change.

Default: false

type

String final

JavaScript class name for this Component.

This is used when loading Scenes from JSON, and is included in the JSON representation of this Component, so that this class may be instantiated when loading it from the JSON representation.

For example: "xeogl.AmbientLight", "xeogl.ColorTarget", "xeogl.Lights" etc.

worldBoundary

Boundary3D

The World-space Boundary3D followed by this CameraFollowAnimation.

Must be within the same Scene as this CameraFollowAnimation. Defaults to the parent Scene's worldBoundary when set to a null or undefined value.

Fires a worldBoundary event on change.

Events

camera

Fired whenever this CameraFollowAnimation's camera property changes.

Event Payload:

  • value Object

    The property's new value

destroyed

Fired when this Component is destroyed.

fit

Fired whenever this CameraFollowAnimation's fit property changes.

Event Payload:

  • value Object

    The property's new value

fitFOV

Fired whenever this CameraFollowAnimation's fitFOV property changes.

Event Payload:

  • value Object

    The property's new value

fly

Fired whenever this CameraFollowAnimation's fly property changes.

Event Payload:

  • value Object

    The property's new value

trail

Fired whenever this CameraFollowAnimation's trail property changes.

Event Payload:

  • value Object

    The property's new value

worldBoundary

Fired whenever this CameraFollowAnimation's worldBoundary property changes.

Event Payload:

  • value Object

    The property's new value