API Docs for: 1.0.0

HeightmapGeometry

Extends Geometry
Module: geometry
Parent Module: xeogl

A Heightmap extends Geometry to define a height mapped geometry for attached Entities.

Overview

  • A HeightmapGeometry is a grid shape, to which the Y-axis is perpendicular.
  • The height of each vertex on the Y-axis is determined by the image file referenced by the HeightmapGeometry's src property.
  • Set the src property to a different image file at any time, to regenerate the HeightmapGeometry's mesh from the new image.
  • Also dynamically modify it's shape at any time by updating its center, xSize, ySize, zSize, xSegments, zSegments and autoNormals properties.
  • Dynamically switch its primitive type between "points", "lines" and "triangles" at any time by updating its primitive property.
  • Leave its autoNormals property true to make it automatically generate its vertex normal vectors.

Examples

Usage

new xeogl.Entity({
    geometry: new xeogl.HeightmapGeometry({
        primitive: "triangles",
        src: "textures/height/mountain.png",
        center: [0,0,0],
        xSize: 10,
        ySize: 5,
        zSize: 10,
        xSegments: 70,
        zSegments: 70,
        lod: 1.0, // Default
        autoNormals: true // Default
    }),
    material: new xeogl.PhongMaterial({
        diffuseMap: new xeogl.Texture({
            src: "textures/diffuse/uvGrid2.jpg"
        })
    }),
    modes: new xeogl.Modes({
        backfaces: true // So that we can see the faces from underneath
    })
});

Constructor

HeightmapGeometry

(
  • [scene]
  • [cfg]
)

Parameters:

  • [scene] Scene optional

    Parent Scene - creates this Heightmap in the default Scene when omitted.

  • [cfg] optional

    Configs

    • [id] String optional

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

    • [meta] String:Object optional

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

    • [primitive="triangles"] String optional

      The primitive type. Accepted values are 'points', 'lines', 'line-loop', 'line-strip', 'triangles', 'triangle-strip' and 'triangle-fan'.

    • [src=undefined] String optional

      Path to an image file to source this Heightmap from.

    • [image=undefined] HTMLImageElement optional

      An HTML DOM Image object to source this Heightmap from.

    • [center] Float32Array optional

      3D point indicating the center position of the BoxGeometry.

    • [xSize=1] Number optional

      Dimension on the X-axis.

    • [ySize=0.25] Number optional

      Dimension on the Y-axis.

    • [zSize=1] Number optional

      Dimension (height) on the Z-axis.

    • [xSegments=1] Number optional

      Number of segments on the X-axis (width).

    • [zSegments=1] Number optional

      Number of segments on the Z-axis (depth).

    • [autoNormals=true] Boolean optional

      Automatically generate vertex normal vectors when true.

    • [lod=1] Level-of-detail, in range [0..1] Number optional

      .

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(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 configuration:

var material2 = component.create(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. You can release the shared component instance with a call to Scene/putSharedComponent:method, and once you have released it as many times as you got it, the Scene will destroy the component.

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

autoNormals

Boolean

Set true to make this Geometry automatically generate normals from positions and indices.

When true, causes this Geometry to auto-generate its normals on the next Scene Scene/tick:event event.

Fires an autoNormals event on change.

Default: false

center

Float32Array

3D point indicating the center position of this HeightmapGeometry.

Fires an center event on change.

Default: [0,0,0]

colors

Float32Array

The Geometry's vertex colors array.

Fires a colors event on change.

Default: null

destroyed

Boolean

True as soon as this Component has been destroyed

id

String final

Unique ID for this Component within its parent Scene.

image

HTMLImageElement

Indicates an HTML DOM Image object to source this Heightmap from.

Alternatively, you could indicate the source via the Heightmap/src:property property.

Fires an Heightmap/image:event event on change.

Sets the Heightmap/src:property to null.

Default: null

indices

Uint16Array | Uint32Array

The Geometry's indices array.

If xeogl.WEBGL_INFO.SUPPORTED_EXTENSIONS["OES_element_index_uint"] is true, then this can be a Uint32Array, otherwise it needs to be a Uint16Array.

Fires a indices event on change.

Default: null

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.

localBoundary

Boundary3D final

Local-space 3D boundary enclosing the positions of this Geometry.

The a Boundary3D is lazy-instantiated the first time that this property is referenced. If destroy is then called on it, then this property will be assigned to a fresh Boundary3D instance next time it's referenced.

The Boundary3D will fire an updated event whenever this Geometry's positions are updated.

lod

Number

The Heightmap's level-of-detail factor.

Fires a Heightmap/lod:event event on change.

Default: 1

metadata

Object

Arbitrary, user-defined metadata on this component.

normals

Float32Array

The Geometry's vertex normal vectors array.

Fires a normals event on change.

Default: null

positions

Float32Array

The Geometry's positions array.

This property is a one-dimensional, flattened array - use xeogl.math/flatten:method to convert two-dimensional arrays for assignment to this property.

Fires a positions event on change.

Default: null

primitive

String

The Geometry's primitive type.

Valid types are: 'points', 'lines', 'line-loop', 'line-strip', 'triangles', 'triangle-strip' and 'triangle-fan'.

Fires a primitive event on change.

Default: "triangles"

scene

Scene final

The parent Scene that contains this Component.

src

String

Indicates a path to an image file to source this Heightmap from.

Alternatively, you could indicate the source via the Heightmap/image:property property.

Fires a Heightmap/src:event event on change.

Sets the Heightmap/image:property to null.

Default: null

string

String final

Inherited from Component but overwritten in src/component.js:1058

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.

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.

usage

String

The Geometry's usage type.

Accepted values are 'static', 'dynamic' and 'stream'.

Fires a usage event on change.

Default: "triangles"

uv

Float32Array

The Geometry's UV coordinate array.

Fires a Geometry/uv:event event on change.

Default: null

xSegments

Number

The Heightmap's number of segments on the X-axis.

Fires a Heightmap/xSegments:event event on change.

Default: 100

xSize

Number

The Heightmap's dimension on the X-axis.

Fires a Heightmap/xSize:event event on change.

Default: 1

ySize

Number

The Heightmap's dimension on the Y-axis.

Fires a Heightmap/ySize:event event on change.

Default: 0.25

zSegments

Number

The Heightmap's number of segments on the Z-axis.

Fires a Heightmap/zSegments:event event on change.

Default: 100

zSize

Number

The Heightmap's dimension (height) on the Z-axis.

Fires a Heightmap/zSize:event event on change.

Default: 1.0

Events

autoNormals

Boolean

Fired whenever this Geometry's autoNormals property changes.

Event Payload:

  • value Object

    The property's new value

center

Fired whenever this HeightmapGeometry's center property changes.

Event Payload:

  • value Float32Array

    The property's new value

colors

Fired whenever this Geometry's colors property changes.

Event Payload:

  • value Object

    The property's new value

destroyed

Fired when this Component is destroyed.

image

Fired whenever this Heightmap's Heightmap/image:property property changes.

Event Payload:

  • value HTML Image

    The property's new value

image

Fired whenever this Heightmap's Heightmap/image:property property changes.

Event Payload:

  • value HTML Image

    The property's new value

indices

Inherited from Geometry but overwritten in src/geometry/geometry.js:1399

Fired whenever this Geometry's indices property changes.

Event Payload:

  • value Object

    The property's new value

loaded

Fired whenever this HeightmapGeometry has rebuilt itself after an update to the Heightmap/src:property or Heightmap/image:property properties.

Event Payload:

  • value Heightmap

    This Heightmap

lod

Number

Fired whenever this Heightmap's Heightmap/lod:property property changes.

Event Payload:

  • value Object

    The property's new value

normals

Fired whenever this Geometry's normals property changes.

Event Payload:

  • value Object

    The property's new value

positions

Inherited from Geometry but overwritten in src/geometry/geometry.js:1110

Fired whenever this Geometry's positions property changes.

Event Payload:

  • value Object

    The property's new value

primitive

String

Fired whenever this Geometry's primitive property changes.

Event Payload:

  • value Object

    The property's new value

src

String

Fired whenever this Heightmap's Heightmap/src:property property changes.

Event Payload:

  • value Object

    The property's new value

usage

String

Fired whenever this Geometry's usage property changes.

Event Payload:

  • value Object

    The property's new value

uvs

Fired whenever this Geometry's Geometry/uvs:property property changes.

Event Payload:

  • value Object

    The property's new value

xSegments

Number

Fired whenever this Heightmap's Heightmap/xSegments:property property changes.

Event Payload:

  • value Object

    The property's new value

xSize

Number

Fired whenever this Heightmap's Heightmap/xSize:property property changes.

Event Payload:

  • value Object

    The property's new value

ySize

Number

Fired whenever this Heightmap's Heightmap/ySize:property property changes.

Event Payload:

  • value Object

    The property's new value

zSegments

Number

Fired whenever this Heightmap's Heightmap/zSegments:property property changes.

Event Payload:

  • value Object

    The property's new value

zSize

Number

Fired whenever this Heightmap's Heightmap/zSize:property property changes.

Event Payload:

  • value Object

    The property's new value