A
Property which evaluates to a Cartesian3 vector
based on the velocity of the provided PositionProperty.
| 参数名称 | 类型 | 默认值 | 描述信息 |
|---|---|---|---|
position |
PositionProperty | 可选 The position property used to compute the velocity. | |
normalize |
boolean |
true
|
可选 Whether to normalize the computed velocity vector. |
使用示例:
//Create an entity with a billboard rotated to match its velocity.
const position = new Cesium.SampledProperty();
position.addSamples(...);
const entity = viewer.entities.add({
position : position,
billboard : {
image : 'image.png',
alignedAxis : new Cesium.VelocityVectorProperty(position, true) // alignedAxis must be a unit vector
}
}));成员(属性)
readonly definitionChanged : Event
Gets the event that is raised whenever the definition of this property changes.
Gets a value indicating if this property is constant.
Gets or sets whether the vector produced by this property
will be normalized or not.
position : Property|undefined
Gets or sets the position property used to compute the velocity vector.
方法
Compares this property to the provided property and returns
true if they are equal, false otherwise.
| 参数名称 | 类型 | 描述信息 |
|---|---|---|
other |
Property | 可选 The other property. |
返回值:
true if left and right are equal, false otherwise.
getValue(time, result) → Cartesian3
Gets the value of the property at the provided time.
| 参数名称 | 类型 | 默认值 | 描述信息 |
|---|---|---|---|
time |
JulianDate |
JulianDate.now()
|
可选 The time for which to retrieve the value. If omitted, the current system time is used. |
result |
Cartesian3 | 可选 The object to store the value into, if omitted, a new instance is created and returned. |
返回值:
The modified result parameter or a new instance if the result parameter was not supplied.