{{tag>graphic skin texture absorption}}
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[[:start|Start Page]] >> [[:gamedev|Game Development with the Drag[en]gine]] >> [[gamedev:skinproperties|Skin Texture Properties]] >> [[gamedev:texturepropertylist|Texture Property Database]] >> **absorption**
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====== Skin Texture Property: absorption ======

Defines the sub surface absorption factor as typically used for human skin to look more realistic.

|Excepted Data Source|1 component image|
|Data Range|0 to 1|
|Default Value|0|
|Affected Modules|Graphic|
|Linked Properties|[[absorption_range|absorption.range]]|

====== Description ======

The **absorption** texture property defines the sub surface absorption factor of a material. Sub surface absorption affects light entering the material after surface based texture properties have taken effect. Sub surface absorption has two main effects. The first is that light is scattered under the surface and exits at a nearby point. This effect gives human skin, way, marble and similar materials their characteristic look. With human skin for example missing the sub surface light scattering the skin looks like plastic and annatural. Due to the sub surface light scattering the skin looks softer and fleshier. The second effect is translucency. Due to the same sub surface absorption effect the light can penetrate the material and exit at the shadow side of the material. The intensity of the light exciting the surface on the other side depends on the thickness of the material and the absorption properties of the material. In both cases the **absorption** texture property defines the factor of absorption relative to the [[absorption_range|absorption.range]] texture property. Splitting the absorption factor out the full range of an 8-bit image can be used to define the absorption even for small or very high values. See [[absorption_range|absorption.range]] texture property for the use of the range to obtain more fine tuned results.


The source is typically an image with 1 color component with values 0 to 1.

The default value for this texture property is 0 which disables sub surface light absorption and scattering.

====== Examples ======

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{{ :gamedev:textureproperties:absorption_0.jpg?direct&300 |Stanford dragon model with 0 absorption and back-lit.}}
<WRAP centeralign>Stanford dragon model with 0 absorption and back-lit. This could be metal or polished plastic.</WRAP>
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{{ :gamedev:textureproperties:absorption_1.jpg?direct&300 |Stanford dragon model with 0.05 absorption range and back-lit.}}
<WRAP centeralign>Stanford dragon model with 0.05 absorption range and back-lit. The added sub surface light absorption gives a glassy look.</WRAP>
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{{ :gamedev:textureproperties:absorption_2.jpg?direct&300 |Stanford armadillo with human skin and 0 absorption.}}
<WRAP centeralign>Stanford armadillo model with human skin and 0 absorption. The skin looks like plastic due to the missing sub surface light scattering. The main reason are the hard shadows.</WRAP>
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{{ :gamedev:textureproperties:absorption_3.jpg?direct&300 |Stanford armadillo with human skin, 0.02 absorption range and (1,1/3,1/6) absorption.}}
<WRAP centeralign>Stanford armadillo with human skin, 0.02 absorption range and (1,1/3,1/6) absorption. The shadows receive now the skin typical brightening up especially in the redish colro specturm.</WRAP>
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