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Effect framework: Difference between revisions
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+-heading levels: First level should not be used manually, it is automatically used for the page title; +related: Forum topic about which kind of groups an effect can be applied to
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(+-heading levels: First level should not be used manually, it is automatically used for the page title; +related: Forum topic about which kind of groups an effect can be applied to) |
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FlightGear. | FlightGear. | ||
=Default Effects in Terrain Materials and Models= | == Default Effects in Terrain Materials and Models == | ||
Effects for terrain work in this way: for each material type in | Effects for terrain work in this way: for each material type in | ||
materials.xml an effect is created that inherits from a single default | materials.xml an effect is created that inherits from a single default | ||
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* texture type, image, filter, wrap-s, wrap-t | * texture type, image, filter, wrap-s, wrap-t | ||
=Specifying Custom Effects= | == Specifying Custom Effects == | ||
You can specify the effects that will be used by FlightGear as the | You can specify the effects that will be used by FlightGear as the | ||
base effect when it creates terrain and model effects. | base effect when it creates terrain and model effects. | ||
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will be animated. | will be animated. | ||
=Examples= | == Examples == | ||
The $FGDATA/Effects directory contains the effects definitions; look there for | The $FGDATA/Effects directory contains the effects definitions; look there for | ||
examples. Effects/crop.eff is a good example of a complex effect. | examples. Effects/crop.eff is a good example of a complex effect. | ||
=Application= | == Application == | ||
To apply an effect to a model or part of a model use: | To apply an effect to a model or part of a model use: | ||
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The effect does not need the file extension. | The effect does not need the file extension. | ||
===Parameters in model file=== | === Parameters in model file === | ||
Parameters can be put into the model files effect application as well. But only bool, int, float, string can be used there. | Parameters can be put into the model files effect application as well. But only bool, int, float, string can be used there. | ||
===Chrome old usage=== | === Chrome old usage === | ||
Chrome, although now implemented as an effect, still retains the old method of application: | Chrome, although now implemented as an effect, still retains the old method of application: | ||
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in order to maintain backward compatibility. | in order to maintain backward compatibility. | ||
=The xml tags of an effect= | == The xml tags of an effect == | ||
==name== | === name === | ||
The name of the effect | The name of the effect | ||
==inherits-from== | === inherits-from === | ||
One feature not fully illustrated in the sample below is that | One feature not fully illustrated in the sample below is that | ||
effects can inherit from each other. The parent effect is listed in | effects can inherit from each other. The parent effect is listed in | ||
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parameters section. | parameters section. | ||
==Parameters== | === Parameters === | ||
Custom parameters that controls the effect. | Custom parameters that controls the effect. | ||
Note that parameters can use the <use> tags to enable properties to specify the values. | Note that parameters can use the <use> tags to enable properties to specify the values. | ||
==Generate== | === Generate === | ||
Often shader effects need tangent vectors to work properly. These | Often shader effects need tangent vectors to work properly. These | ||
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holds the tangent value for the vertex. | holds the tangent value for the vertex. | ||
==Technique== | === Technique === | ||
A certain way of rendering this effect. Different pipelines typically have their own techniques. | A certain way of rendering this effect. Different pipelines typically have their own techniques. | ||
===predicate=== | ==== predicate ==== | ||
A technique can contain a predicate that describes the OpenGL | A technique can contain a predicate that describes the OpenGL | ||
functionality required to support the technique. The first | functionality required to support the technique. The first | ||
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</syntaxhighlight> | </syntaxhighlight> | ||
===pass=== | ==== pass ==== | ||
A technique can consist of several passes. A pass is basically an Open | A technique can consist of several passes. A pass is basically an Open | ||
Scene Graph StateSet. Ultimately all OpenGL and OSG modes and state | Scene Graph StateSet. Ultimately all OpenGL and OSG modes and state | ||
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changes. | changes. | ||
====lighting==== | ===== lighting ===== | ||
true or false | true or false | ||
====material==== | ===== material ===== | ||
children: active, ambient, ambient-front, ambient-back, diffuse, | children: active, ambient, ambient-front, ambient-back, diffuse, | ||
diffuse-front, diffuse-back, specular, specular-front, | diffuse-front, diffuse-back, specular, specular-front, | ||
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shininess-front, shininess-back, color-mode | shininess-front, shininess-back, color-mode | ||
====blend==== | ===== blend ===== | ||
Children: active, source, destination, source-rgb, source-alpha, destination-rgb, destination-alpha | Children: active, source, destination, source-rgb, source-alpha, destination-rgb, destination-alpha | ||
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</syntaxhighlight> | </syntaxhighlight> | ||
====shade-model==== | ===== shade-model ===== | ||
flat or smooth | flat or smooth | ||
====cull-face==== | ===== cull-face ===== | ||
front, back, front-back, off | front, back, front-back, off | ||
====texture-unit==== | ===== texture-unit ===== | ||
Example: | Example: | ||
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</syntaxhighlight> | </syntaxhighlight> | ||
====vertex-program-two-side==== | ===== vertex-program-two-side ===== | ||
true or false | true or false | ||
====polygon-mode==== | ===== polygon-mode ===== | ||
children: front, back | children: front, back | ||
Valid values: fill, line, point | Valid values: fill, line, point | ||
====vertex-program-point-size==== | ===== vertex-program-point-size ===== | ||
true, false | true, false | ||
====uniform==== | ===== uniform ===== | ||
Data accessible by shaders. | Data accessible by shaders. | ||
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type: bool, int, float, float-vec3, float-vec4, sampler-1d, sampler-2d, sampler-3d, sampler-1d-shadow, sampler-2d-shadow, sampler-cube | type: bool, int, float, float-vec3, float-vec4, sampler-1d, sampler-2d, sampler-3d, sampler-1d-shadow, sampler-2d-shadow, sampler-cube | ||
====alpha-test==== | ===== alpha-test ===== | ||
active: true, false | active: true, false | ||
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reference: 0 to 1 | reference: 0 to 1 | ||
====render-bin==== | ===== render-bin ===== | ||
Sent to OSG. | Sent to OSG. | ||
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bin-name: RenderBin, DepthSortedBin | bin-name: RenderBin, DepthSortedBin | ||
====rendering-hint==== | ===== rendering-hint ===== | ||
Sent to OSG. | Sent to OSG. | ||
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default = inherit renderbin details from parent node | default = inherit renderbin details from parent node | ||
====program==== | ===== program ===== | ||
* vertex-shader | * vertex-shader | ||
* geometry-shader | * geometry-shader | ||
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See this page for more about shaders: [[Howto:Shader programming in FlightGear]] | See this page for more about shaders: [[Howto:Shader programming in FlightGear]] | ||
=Uniforms passed to shaders outside the xml effect framework= | == Uniforms passed to shaders outside the xml effect framework == | ||
{| class="wikitable" | {| class="wikitable" | ||
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|Defined by OSG | |Defined by OSG | ||
|} | |} | ||
== Related content == | |||
=== Forum topics === | |||
* {{forum link|t=37364|title=Application of effects}} - Testing which kind of groups an effect can be applied to and when | |||
[[Category:Shader development]] | [[Category:Shader development]] | ||