A point is created and its initial properties are set by calling
A graphical point positioned in the 3D scene, that is created
and rendered using a PointPrimitiveCollection#add
. Do not call the constructor directly.
PointPrimitiveCollection
.
Performance:
Reading a property, e.g., PointPrimitive#show
, is constant time.
Assigning to a property is constant time but results in
CPU to GPU traffic when PointPrimitiveCollection#update
is called. The per-pointPrimitive traffic is
the same regardless of how many properties were updated. If most pointPrimitives in a collection need to be
updated, it may be more efficient to clear the collection with PointPrimitiveCollection#removeAll
and add new pointPrimitives instead of modifying each one.
Throws:
-
DeveloperError : scaleByDistance.far must be greater than scaleByDistance.near
-
DeveloperError : translucencyByDistance.far must be greater than translucencyByDistance.near
-
DeveloperError : distanceDisplayCondition.far must be greater than distanceDisplayCondition.near
成员(属性)
Gets or sets the inner color of the point.
The red, green, blue, and alpha values are indicated by
value
's red
, green
,
blue
, and alpha
properties as shown in Example 1. These components range from 0.0
(no intensity) to 1.0
(full intensity).
使用示例s:
// Example 1. Assign yellow.
p.color = Cesium.Color.YELLOW;
// Example 2. Make a pointPrimitive 50% translucent.
p.color = new Cesium.Color(1.0, 1.0, 1.0, 0.5);
Gets or sets the distance from the camera at which to disable the depth test to, for example, prevent clipping against terrain.
When set to zero, the depth test is always applied. When set to Number.POSITIVE_INFINITY, the depth test is never applied.
-
默认值:
0.0
distanceDisplayCondition : DistanceDisplayCondition
Gets or sets the condition specifying at what distance from the camera that this point will be displayed.
-
默认值:
undefined
Gets or sets the user-defined value returned when the point is picked.
outlineColor : Color
Gets or sets the outline color of the point.
Gets or sets the outline width in pixels. This width adds to pixelSize,
increasing the total size of the point.
Gets or sets the inner size of the point in pixels.
Gets or sets the Cartesian position of this point.
scaleByDistance : NearFarScalar
Gets or sets near and far scaling properties of a point based on the point's distance from the camera.
A point's scale will interpolate between the
NearFarScalar#nearValue
and
NearFarScalar#farValue
while the camera distance falls within the lower and upper bounds
of the specified NearFarScalar#near
and NearFarScalar#far
.
Outside of these ranges the point's scale remains clamped to the nearest bound. This scale
multiplies the pixelSize and outlineWidth to affect the total size of the point. If undefined,
scaleByDistance will be disabled.
使用示例s:
// Example 1.
// Set a pointPrimitive's scaleByDistance to scale to 15 when the
// camera is 1500 meters from the pointPrimitive and disappear as
// the camera distance approaches 8.0e6 meters.
p.scaleByDistance = new Cesium.NearFarScalar(1.5e2, 15, 8.0e6, 0.0);
// Example 2.
// disable scaling by distance
p.scaleByDistance = undefined;
Determines if this point will be shown. Use this to hide or show a point, instead
of removing it and re-adding it to the collection.
splitDirection : SplitDirection
The
SplitDirection
to apply to this point.
-
默认值:
SplitDirection.NONE
translucencyByDistance : NearFarScalar
Gets or sets near and far translucency properties of a point based on the point's distance from the camera.
A point's translucency will interpolate between the
NearFarScalar#nearValue
and
NearFarScalar#farValue
while the camera distance falls within the lower and upper bounds
of the specified NearFarScalar#near
and NearFarScalar#far
.
Outside of these ranges the point's translucency remains clamped to the nearest bound. If undefined,
translucencyByDistance will be disabled.
使用示例s:
// Example 1.
// Set a point's translucency to 1.0 when the
// camera is 1500 meters from the point and disappear as
// the camera distance approaches 8.0e6 meters.
p.translucencyByDistance = new Cesium.NearFarScalar(1.5e2, 1.0, 8.0e6, 0.0);
// Example 2.
// disable translucency by distance
p.translucencyByDistance = undefined;
方法
computeScreenSpacePosition(scene, result) → Cartesian2
Computes the screen-space position of the point's origin.
The screen space origin is the top, left corner of the canvas;
x
increases from
left to right, and y
increases from top to bottom.
参数名称 | 类型 | 描述信息 |
---|---|---|
scene |
Scene | The scene. |
result |
Cartesian2 | 可选 The object onto which to store the result. |
返回值:
The screen-space position of the point.
Throws:
-
DeveloperError : PointPrimitive must be in a collection.
使用示例:
console.log(p.computeScreenSpacePosition(scene).toString());
Determines if this point equals another point. Points are equal if all their properties
are equal. Points in different collections can be equal.
参数名称 | 类型 | 描述信息 |
---|---|---|
other |
PointPrimitive | The point to compare for equality. |
返回值:
true
if the points are equal; otherwise, false
.