Feature Geometry¶
This plugin renders vector feature data into OSG geometry using style sheets.
Example usage:
<model driver="feature_geom">
<features driver="ogr">
<url>world.shp</url>
</features>
<styles>
<style type="text/css">
default {
stroke: #ffff00;
stroke-width: 2;
}
</style>
</styles>
<fading duration="1.0"/>
</model>
Properties:
- geo_interpolation
How to interpolate geographic lines; options are
great_circle
orrhumb_line
- instancing
For point model substitution, whether to use GL draw-instanced (default is
false
)
Shared properties:
All the feature-rendering drivers share the following properties (in addition to those above):
- styles
Stylesheet to use to render features (see: Symbology Reference)
- layout
Paged data layout (see: Features & Symbology)
- cache_policy
Caching policy (see: Caching)
- fading
Fading behavior (see: Fading)
- feature_name
Expression evaluating to the attribute name containing the feature name
- feature_indexing
Whether to index features for query (default is
false
)- lighting
Whether to override and set the lighting mode on this layer (t/f)
- max_granularity
Anglular threshold at which to subdivide lines on a globe (degrees)
- shader_policy
Options for shader generation (see: Shader Policy) :use_texture_arrays: Whether to use texture arrays for wall and roof skins if you’re card supports them. (default is
true
)
Also see:
feature_rasterize.earth
sample in the repo
Fading¶
When fading is supported on a model layer, you can control it like so:
<model ...
<fading duration = "1.0"
max_range = "6000"
attenuation_distance = "1000" />
Properties:
- duration
Time over which to fade in (seconds)
- max_range
Distance at which to start the fade-in
- attenuation_distance
Distance over which to fade in
Shader Policy¶
Some drivers support a shader policy that lets you control how (or whether) to generate shaders for external geometry. For example, if you want to load an external model via a stylesheet, but do NOT want osgEarth to generate shaders for it:
<model ...
<shader_policy>disable</shader_policy>