[原][译][osgearth]样式表style中参数总结（OE官方文档翻译）

几何Geometry

高度Altitude

挤压Extrusion

图标Icon

模型Model

渲染Render

皮肤Skin

文本Text

覆盖Coverage

提示：　　在SDK中，样式表的命名空间是osgEarth::Symbology

　　　　　　每个符号类是在AltitudeSymbol中，属性通过

LineSymbol::strokeWidth()

访问器可用

值类型

float:	实数
float with units:	有单位的实数, e.g. 20px (20 pixels) or 10m (10 meters)
HTML_Color:	颜色以十六进制格式字符串,用于HTML;# RRGGBB或# RRGGBBAA的格式。(例如:# FFCC007F)
integer:	整数
numeric_expr:	表达式(简单或JavaScript)解决一个数字
string:	字符串
string_expr:	表达式(简单或JavaScript)解决一个文本字符串
uri_string:	表示(如URL资源位置的字符串或文件路径)。

几何Geometry

基本几何符号(SDK:LineSymbol、PolygonSymbol PointSymbol)控制矢量数据的颜色和风格

Property	Description	Value(s)
fill	Fill color for a polygon.	HTML color
stroke	Line color (or polygon outline color, if fill is present)	HTML color
stroke-width	Line width	float with units
stroke-min-pixels	Minimum rendering width; Prevents a line from getting thinner than this value in pixels. Only applies when the stroke-width is NOT in pixels	float (pixels)
stroke-tessellation	Number of times to subdivide a line	integer
stroke-linejoin	Join style for polygonized lines. Only applies with stroke-width is in world units (and not pixels)	miter, round
stroke-linecap	Cap style for polygonized lines. Only applies with stroke-width is in world units (and not pixels)	square, flat, round
stroke-rounding-ratio	For joins and caps that are set to round , the resolution of the rounded corner. Value is the ratio of line width to corner segment length.	float (0.4)
stroke-stipple-pattern	Stippling pattern bitmask. Each set bit represents an “on” pixel in the pattern.	integer (65535)
stroke-stipple-factor	Stipple factor for pixel-width lines. Number of times to repeat each bit in the stippling pattern	integer (1)
stroke-crease-angle	When outlining extruded polygons, only draw a post outline if the angle between the adjoining faces exceeds this value. This has the effect of only outlining corners that are sufficiently “sharp”.	float degrees (0.0)
point-fill	Fill color for a point.	HTML color
point-size	Size for a GL point geometry

高度Altitude

高度的符号(SDK:AltitudeSymbol)控制功能与地形的交互在它的位置。

Property	Description
altitude-clamping	控制地形的行为 none: no clamping terrain: 跟随地形 relative: 跟随地形但保留Z值 absolute: 使用Z的绝对值
altitude-technique	当 altitude-clamping 设置 terrain 模式的时候，使用 map: 使用地图的高度数据 drape: 用投影纹理数据 gpu: 用GPU的数据 scene: 用心的分页数据重新加载
altitude-binding	当 altitude-technique 选择 map，使用的间隔 vertex: 每个顶点 centroid: 每个特征的中心
altitude-resolution	当“altitude-technique”选择“map”，高程使用和样例地形高度一样的分辨率数据
altitude-offset	垂直偏移
altitude-scale	缩放

挤压Extrusion

挤压符号(SDK:ExtrusionSymbol)指导osgEarth创建挤压几何从源矢量数据;挤压一个2 d向量转化为3 d形状。注意:简单的anextrusion属性将使挤压。

Property	Description
extrusion-height	How far to extrude the vector data (numeric-expr)
extrusion-flatten	Whether to force all extruded vertices to the same Z value (bool). For example, if you are extruding polygons to make 3D buildings, setting this to true will force the rooftops to be flat even if the underlying terrain is not. (boolean)
extrusion-wall-gradient	Factor by which to multiply the fill color of the extruded geometry at the base of the 3D shape. This results in the 3D shape being darker at the bottom than at the top, a nice effect. (float [0..1]; try 0.75)
extrusion-wall-style	Name of another style in the same stylesheet that osgEarth should apply to the walls of the extruded shape. (string)
extrusion-roof-style	Name of another style in the same stylesheet that osgEarth should apply to the roof of the extruded shape. (string)

图标Icon

图标符号(SDK:IconSymbol)描述二维图标的外观。图标是用于不同的东西,最常见的是:
点替换,用图标代替几何模型
注释的地方

Property	Description
icon	URI of the icon image. (uri-string)
icon-library	Name of a resource library containing the icon (optional)
icon-placement	For model substitution, describes how osgEarth should replace geometry with icons: vertex: Replace each vertex in the geometry with an icon. interval: Place icons at regular intervals along the geometry, according to the icon-density property. random: Place icons randomly within the geometry, according to the icon-density property. centroid: Place a single icon at the centroid of the geometry.
icon-density	For icon-placement settings of interval or random , this property is hint as to how many instances osgEarth should place. The unit is approximately “units per km” (for linear data) or “units per square km” for polygon data. (float)
icon-scale	Scales the icon by this amount (float)
icon-heading	Rotates the icon along its central axis (float, degrees)
icon-declutter	Activate decluttering for this icon. osgEarth will attempt to automatically show or hide things so they don’t overlap on the screen. (boolean)
icon-align	Sets the icon’s location relative to its anchor point. The valid values are in the form “horizontal-vertical”, and are: left-top left-center left-bottom center-top center-center center-bottom right-top right-center right-bottom
icon-random-seed	For random placement operations, set this seed so that the randomization is repeatable each time you run the app. (integer)
icon-occlusion-cull	Whether to occlusion cull the text so they do not display when line of sight is obstructed by terrain
icon-occlusion-cull-altitude	The viewer altitude (MSL) to start occlusion culling when line of sight is obstructed by terrain

模型Model

模型符号(SDK:ModelSymbol)描述了外部的3 d模型。如图标,模型通常用于:
点替换,用3 d模型代替几何模型
模型的注释

Property	Description
model	URI of the 3D model (uri-string). Use this OR the model-library property, but not both.
model-library	Name of a resource library containing the model. Use this OR the model property, but not both.
model-placement	For model substitution, describes how osgEarth should replace geometry with models: vertex: Replace each vertex in the geometry with a model. interval: Place models at regular intervals along the geometry, according to the model-density property. random: Place models randomly within the geometry, according to the model-density property. centroid: Place a single model at the centroid of the geometry.
model-density	For model-placement settings of interval or random , this property is hint as to how many instances osgEarth should place. The unit is approximately “units per km” (for linear data) or “units per square km” for polygon data. (float)
model-scale	Scales the model by this amount along all axes (float)
model-heading	Rotates the about its +Z axis (float, degrees)
icon-random-seed	For random placement operations, set this seed so that the randomization is repeatable each time you run the app. (integer)

渲染Render

渲染符号(SDK:RenderSymbol)适用于一般OpenGL渲染设置以及一些osgEarth-specific设置并非特定于任何其他符号类型。

Property	Description
render-depth-test	Enable or disable GL depth testing. (boolean)
render-lighting	Enable or disable GL lighting. (boolean)
render-transparent	hint to render in the transparent (depth-sorted) bin (boolean)
render-bin	render bin to use for sorting (string)
render-depth-offset	Enable or disable Depth Offseting. Depth offsetting is a GPU technique that modifies a fragment’s depth value, simulating the rendering of that object closer or farther from the viewer than it actually is. It is a mechanism for mitigating z-fighting. (boolean)
render-depth-offset-min-bias	Sets the minimum bias (distance-to-viewer offset) for depth offsetting. If is usually sufficient to set this property; all the others will be set automatically. (float, meters)
render-depth-offset-max-bias	Sets the minimum bias (distance-to-viewer offset) for depth offsetting.
render-depth-offset-min-range	Sets the range (distance from viewer) at which to apply the minimum depth offsetting bias. The bias graduates between its min and max values over the specified range.
render-depth-offset-max-range	Sets the range (distance from viewer) at which to apply the maximum depth offsetting bias. The bias graduates between its min and max values over the specified range.

皮肤Skin

皮肤象征(SDK:SkinSymbol)纹理映射适用于几何形状,当适用。(目前只适用于挤压几何)。

Property	Description
skin-library	Name of the resource library containing the skin(s)
skin-tags	Set of strings (separated by whitespace containing one or more resource tags. When selecting a texture skin to apply, osgEarth will limit the selection to skins with one of these tags. If you omit this property, all skins are considered. For example, if you are extruding buildings, you may only want to consider textures with the building tag. (string)
skin-tiled	When set to true , osgEarth will only consider selecting a skin that has its tiled attribute set to true . The tiled attribute indicates that the skin may be used as a repeating texture. (boolean)
skin-object-height	Numeric expression resolving to the feature’s real-world height (in meters). osgEarth will use this value to narrow down the selection to skins appropriate to that height (i.e., skins for which the value falls between the skin’s min/max object height range. (numeric-expr)
skin-min-object-height	Tells osgEarth to only consider skins whose minimum object height is greater than or equal to this value. (numeric-expr)
skin-max-object-height	Tells osgEarth to only consider skins whose maximum object height is less than or equal to this value. (numeric-expr)
skin-random-seed	Once the filtering is done (according to the properties above, osgEarth determines the minimal set of appropriate skins from which to choose and chooses one at random. By setting this seed value you can ensure that the same “random” selection happens each time you run the appplication. (integer)

文本Text

文字符号(SDK:TextSymbol)控制文本标签的存在和外观。

Property	Description
text-fill	Foreground color of the text (HTML color)
text-size	Size of the text (float, pixels)
text-font	Name of the font to use (system-dependent). For example, use “arialbd” on Windows for Arial Bold.
text-halo	Outline color of the text; Omit this propery altogether for no outline. (HTML Color)
text-halo-offset	Outline thickness (float, pixels)
text-offset-x	The x offset of the text in pixels
text-offset-y	The y offset of the text in pixels
text-align	Alignment of the text string relative to its anchor point: left-top left-center left-bottom left-base-line left-bottom-base-line center-top center-center center-bottom center-base-line center-bottom-base-line right-top right-center right-bottom right-base-line right-bottom-base-line base-line
text-layout	Layout of text: ltr rtl vertical
text-content	The actual text string to display (string-expr)
text-encoding	Character encoding of the text content: utf-8 utf-16 utf-32 ascii
text-declutter	Activate decluttering for this icon. osgEarth will attempt to automatically show or hide things so they don’t overlap on the screen. (boolean)
text-occlusion-cull	Whether to occlusion cull the text so they do not display when line of sight is obstructed by terrain
text-occlusion-cull-altitude	The viewer altitude (MSL) to start occlusion culling when line of sight is obstructed by terrain

覆盖Coverage

覆盖符号(SDK:CoverageSymbol)控制功能是光栅为覆盖率数据的离散值。

PropertyDescriptioncoverage-valueExpression resolving to the floating-point value to encode.