本地存储的地面空间间接实现的 GPM 元数据（即图块和/或叶节点）。这反映了根扩展对象 The GPM metadata for a Ground-Space Indirect implementation stored locally (i.e. a tile and/or leaf node). This reflects the root extension object of the NGA_gpm_local
.glTF 扩展名当加载包含此扩展的模型时，可以通过调用 ``` const gltfGpmLocal = model.getExtension("NGA_gpm_local"); 来获取该类型的对象。 ``` 存储类型决定可选属性的存在： glTF extension. When a model that contains this extension was loaded, then an object of this type can be obtained by calling ``` const gltfGpmLocal = model.getExtension("NGA_gpm_local"); ``` The storage type determines the presence of the optional properties:
- 当存储类型为“StorageType.Indirect”时，则存在“anchorPointsIndirect”和“intraTileCorrelationGroups”。 When the storage type is `StorageType.Indirect`, then the `anchorPointsIndirect` and `intraTileCorrelationGroups` are present.
- 当存储类型为“StorageType.Direct”时，则存在“anchorPointsDirect”和“covarianceDirect”。 When the storage type is `StorageType.Direct`, then the `anchorPointsDirect` and `covarianceDirect` are present.
| 名称 Name | 类型 Type | 说明 Description |
|---|---|---|
options |
GltfGpmLocal.ConstructorOptions | 描述初始化选项的对象 An object describing initialization options |
实验性 Experimental
此功能不是最终版本，可能会在没有 Cesium 标准弃用政策的情况下进行更改。 This feature is not final and is subject to change without Cesium's standard deprecation policy.
成员 Members
readonly anchorPointsDirect : Array.<AnchorPointDirect>|undefined
存储的直接锚点数组 Array of stored direct anchor points
readonly anchorPointsIndirect : Array.<AnchorPointIndirect>|undefined
存储的间接锚点数组 Array of stored indirect anchor points
readonly covarianceDirect : Matrix3|undefined
锚点参数的完全协方差 The full covariance of anchor point parameters
readonly intraTileCorrelationGroups : Array.<CorrelationGroup>|undefined
使用相同的相关性模型和关联的相关性参数来识别参数的元数据 Metadata identifying parameters using same correlation modeling and associated correlation parameters
readonly storageType : StorageType
指定协方差存储是间接的还是直接的。 Specifies if covariance storage is indirect or direct.
类型定义 Type Definitions
GltfGpmLocal 构造函数的初始化选项 Initialization options for the GltfGpmLocal constructor
属性： Properties:
| 名称 Name | 类型 Type | Attributes | 说明 Description |
|---|---|---|---|
storageType |
string | 存储类型。这必须是“StorageType”常量之一，即“Direct”或“Indirect”。 The storage type. This must be one of the `StorageType` constants, i.e. `Direct` or `Indirect`. | |
anchorPointsIndirect |
Array.<AnchorPointIndirect> | undefined |
<可选> <optional> |
间接锚点。当且仅当存储类型为“间接”时，该值才必须存在。 The indirect anchor points. This must be present if and only if the storage type is `Indirect`. |
intraTileCorrelationGroups |
Array.<CorrelationGroup> | undefined |
<可选> <optional> |
瓦片内相关组。当且仅当存储类型为“间接”时，该值才必须存在。 The intra-tile correlation groups. This must be present if and only if the storage type is `Indirect`. |
anchorPointsDirect |
Array.<AnchorPointDirect> | undefined |
<可选> <optional> |
直接锚点。当且仅当存储类型为“直接”时，该值才必须存在。 The direct anchor points. This must be present if and only if the storage type is `Direct`. |
covarianceDirect |
Matrix3 | undefined |
<可选> <optional> |
锚点参数的协方差。当且仅当存储类型为“直接”时，该值才必须存在。 The covariance of anchor point parameters. This must be present if and only if the storage type is `Direct`. |