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Procedural texturing: Difference between revisions
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→Procedural terrain texturing in Flightgear
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(Currently the following requires that Atmospheric Light Scattering is on!) | (Currently the following requires that Atmospheric Light Scattering is on!) | ||
=== Basic texturing scheme === | |||
The texturing scheme is controlled on a per-landclass basis from <b>materials.xml</b>. The relevant sections for procedural textruring in each material declaration are <texture-set> and <parameters>. Here the <texture-set> block controls what textures are used whereas the <parameters> block controls how these textures are used. | |||
Another important part are <xsize> and <ysize> (the sections which describes to which size in meters the base texture is mapped). The procedural texturing shader computes the size of all used textures <i>relative</i> to the base texture size, so if a base texture is declared to have a size of 500 m rather than the default 2000 m, the resolution of the hires overlay or the grain texture will automatically also be 5 times higher then default - which may or may not be desired. | |||
The individual textures which can be used are: | |||
==== Base texture ==== | |||
The base texture is used as in the default scheme to give the basic appearance of a landclass. The base texture is assumed to be opaque, and its alpha channel is hence not evaluated to transparent, but rather used to encode where the autumn color effect should be used. An alpha value of 0.5 is appropriate for deciduous forests which should get a strong red-orange appearance in autumn, a value of 0.8-0.9 is more appropriate for grass surfaces. | |||
[[File:tiling_example.jpg|300px|center|Base Texture]] | |||
The base texture can take one parameter, the intrinsic wetness. If the quality level of the shader supports it, this will make the texture appear wet and add sparkling specular reflections to the terrain even if the surrounding terrain is dry. | |||
* declaration: | |||
<texture-set> | |||
<texture>base_texture.png</texture> | |||
</texture-set> | |||
* parameters: | |||
<parameters> | |||
<intrinsic_wetness>0.0</intrinsic_wetness> | |||
</parameters> | |||
The default value is zero, the parameter can range from 0 (dry) to 1 (very wet, lots of open water). | |||
=== Pixel color postprocessing === | === Pixel color postprocessing === | ||