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gamedev:textureproperties:roughness [2012/12/01 22:18] – dragonlordgamedev:textureproperties:roughness [2019/05/24 23:43] (current) – ↷ Links adapted because of a move operation dragonlord
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 +{{tag>graphic skin texture roughness}}
 <WRAP youarehere> <WRAP youarehere>
-[[:start|Start Page]] >> [[gamedev:main|Game Development with the Drag[en]gine]] >> [[gamedev:skinproperties|Skin Texture Properties]] >> [[gamedev:texturepropertylist|Texture Property Database]] >> **roughness**+[[:start|Start Page]] >> [[:gamedev|Game Development with the Drag[en]gine]] >> [[gamedev:skinproperties|Skin Texture Properties]] >> [[gamedev:texturepropertylist|Texture Property Database]] >> **roughness**
 </WRAP> </WRAP>
  
-<WRAP boxheader> +====== Skin Texture Property: roughness ====== 
-====== Summary ====== + 
-</WRAP> +Defines the roughness of a surface. 
-<WRAP boxcontent> +
-|Texture Property Name|roughness| +
-|Description|Defines the roughness of a surface|+
 |Excepted Data Source|2 component image| |Excepted Data Source|2 component image|
 |Data Range|0 to 1 for all image components| |Data Range|0 to 1 for all image components|
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 |Affected Modules|Graphic| |Affected Modules|Graphic|
 |Linked Properties|[[gamedev:textureproperties:roughness_remap_lower|roughness.remap.lower]], [[gamedev:textureproperties:roughness_remap_upper|roughness.remap.upper]]| |Linked Properties|[[gamedev:textureproperties:roughness_remap_lower|roughness.remap.lower]], [[gamedev:textureproperties:roughness_remap_upper|roughness.remap.upper]]|
-</WRAP> 
  
 ====== Description ====== ====== Description ======
 +
 The **roughness** texture property defines the roughness of the surface. This property is one of the most important properties in the **[[gamedev:pbr|physically based rendering]]** approach. In other game engines specular reflection also includes the surface roughness together with the reflectivity which results in troubles working with such a combined value. The roughness on the other hand decouples the shape of the reflection from the intensity of the reflection. The **[[gamedev:textureproperties:reflectivity|reflectivity]]** texture property determines in general the **intensity of reflections** while this texture property determines the **shape of the reflection**. Two pices of plastic for example have the same **[[gamedev:textureproperties:reflectivity|reflectivity]]**. One of them is though rather smooth with a low roughness value while the other is rather dull with a higher roughness value. The appearance of the plastic is totally different. The different roughness value alters the shape, intensity and bluriness of the reflection on the plastic material. To get a good looking material good values for this texture property are important. The **roughness** texture property defines the roughness of the surface. This property is one of the most important properties in the **[[gamedev:pbr|physically based rendering]]** approach. In other game engines specular reflection also includes the surface roughness together with the reflectivity which results in troubles working with such a combined value. The roughness on the other hand decouples the shape of the reflection from the intensity of the reflection. The **[[gamedev:textureproperties:reflectivity|reflectivity]]** texture property determines in general the **intensity of reflections** while this texture property determines the **shape of the reflection**. Two pices of plastic for example have the same **[[gamedev:textureproperties:reflectivity|reflectivity]]**. One of them is though rather smooth with a low roughness value while the other is rather dull with a higher roughness value. The appearance of the plastic is totally different. The different roughness value alters the shape, intensity and bluriness of the reflection on the plastic material. To get a good looking material good values for this texture property are important.
  
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 Adding small variations to the roughness image can add a lot of credibility to a material. In general use a roughness value above 0.5 for all kind of dents, bumps, cuts, cravices and scratches to underline the microfractures present due to the damage. Also wear and tear as well as weathered parts on a model tend to have roughness value above 0.5 as the material becomes porous and brittle on these places. Also for very dull reflections use roughness values closer to 1 while for glossy to glassy reflections use roughness values close to 0. Using a roughness value of 0 turns the object into a perfect mirror while a roughness value of 1 turns the object into a diffuse lit one. A roughness value of 0.5 is a good starting value. This table here gives you a good starting point: Adding small variations to the roughness image can add a lot of credibility to a material. In general use a roughness value above 0.5 for all kind of dents, bumps, cuts, cravices and scratches to underline the microfractures present due to the damage. Also wear and tear as well as weathered parts on a model tend to have roughness value above 0.5 as the material becomes porous and brittle on these places. Also for very dull reflections use roughness values closer to 1 while for glossy to glassy reflections use roughness values close to 0. Using a roughness value of 0 turns the object into a perfect mirror while a roughness value of 1 turns the object into a diffuse lit one. A roughness value of 0.5 is a good starting value. This table here gives you a good starting point:
  
-<WRAP boxheader> +<WRAP center 100%>
-===== Roughness Table ===== +
-</WRAP> +
-<WRAP boxcontent>+
 ^Material^Roughness^ ^Material^Roughness^
 |Polished plastic or metal|0| |Polished plastic or metal|0|
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 To help artists a **Roughness Chart** is provided. The chart features on top a row of plastic and metal materials as they appear in the game using the default OpenGL graphic module. This gives an impression on how blurry the reflection is and how the shape of the reflections widens and gets weaker with changing roughness values. The lower row is a special row where only the specular reflection of a light source is shown. This row is better suited to compare a real world object if a tiny light source is reflected in the object in a dark room. In the middle is a color picker the artist can use to sample the roughness value he wants to paint with. Click on the image to download it. To help artists a **Roughness Chart** is provided. The chart features on top a row of plastic and metal materials as they appear in the game using the default OpenGL graphic module. This gives an impression on how blurry the reflection is and how the shape of the reflections widens and gets weaker with changing roughness values. The lower row is a special row where only the specular reflection of a light source is shown. This row is better suited to compare a real world object if a tiny light source is reflected in the object in a dark room. In the middle is a color picker the artist can use to sample the roughness value he wants to paint with. Click on the image to download it.
-<WRAP boxheader> +<WRAP download 1100px center> 
-===== Roughness Chart ===== +{{ :gamedev:chart_roughness.png?direct |Roughness Chart for Artists}} 
-</WRAP> +<WRAP centeralign>Roughness Chart for Artists</WRAP>
-<WRAP boxcontent> +
-<WRAP box 1100px center>{{ :gamedev:images:chart_roughness.png |}}<WRAP centeralign>Roughness Chart for Artists</WRAP></WRAP>+
 </WRAP> </WRAP>
 +
  
 Optionally the second color component can be used to specify a different roughness value. This can be used to simulate metals that have anisotropic reflections. A typical example is brushed metal. Due to the brushing the reflections are elongated along perpendicular to the brushing direction. This can be simulated using two different roughness values one for along the brushing direction and the other perpendicular to it. Here this is limited to the texture U and V direction. The red color component (component 0) maps to the U texture direction and the green color component (component 1) maps to the V texture direction. If two color components are used anisotropic reflections are used. If one color component is used normal reflections are used. Using the same value for both color components has the same effect. Optionally the second color component can be used to specify a different roughness value. This can be used to simulate metals that have anisotropic reflections. A typical example is brushed metal. Due to the brushing the reflections are elongated along perpendicular to the brushing direction. This can be simulated using two different roughness values one for along the brushing direction and the other perpendicular to it. Here this is limited to the texture U and V direction. The red color component (component 0) maps to the U texture direction and the green color component (component 1) maps to the V texture direction. If two color components are used anisotropic reflections are used. If one color component is used normal reflections are used. Using the same value for both color components has the same effect.
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 ====== Examples ====== ====== Examples ======
-( TODO: example image )+ 
 +<WRAP center 100%> 
 +<WRAP center box 620px> 
 +{{ :gamedev:textureproperties:roughness.png |Materials with same reflectivity but different roughness}} 
 +<WRAP centeralign>Materials with same reflectivity but different roughness. Left image has a high roughness (rubber). Middle image has average roughness (rough plastic). Right image has very low roughness (polished plastic).</WRAP> 
 +</WRAP> 
 +</WRAP>
gamedev/textureproperties/roughness.1354400328.txt.gz · Last modified: 2012/12/01 22:18 by dragonlord

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