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gamedev:pbr [2012/12/04 23:52] dragonlordgamedev:pbr [2020/04/05 10:36] (current) dragonlord
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 +{{tag>graphic pbr hdrr rendering}}
 <WRAP youarehere> <WRAP youarehere>
-[[:start|Start Page]] >> [[gamedev:main|Game Development with the Drag[en]gine]] >> **Physically based Rendering**+[[:start|Start Page]] >> [[:gamedev|Game Development with the Drag[en]gine]] >> **Physically based Rendering**
 </WRAP> </WRAP>
 +
 +====== Physically based Rendering ======
  
 For a much more in depth discussion about the topic of using physically based rendering in games see the [[http://renderwonk.com/publications/s2010-shading-course/|SIGGRAPH Course Notes]] especially the course notes and slides about //Physically-Based Shading Models in Film and Game Production//. Another source of information can be found in a blogg post about [[http://seblagarde.wordpress.com/2011/08/17/hello-world/|adopting a physically based shading model]]. This page here contains only the important parts to understand the PBR as used in the Drag[en]gine. For a much more in depth discussion about the topic of using physically based rendering in games see the [[http://renderwonk.com/publications/s2010-shading-course/|SIGGRAPH Course Notes]] especially the course notes and slides about //Physically-Based Shading Models in Film and Game Production//. Another source of information can be found in a blogg post about [[http://seblagarde.wordpress.com/2011/08/17/hello-world/|adopting a physically based shading model]]. This page here contains only the important parts to understand the PBR as used in the Drag[en]gine.
  
-====== Ad-hoc Rendering Methods ======+====== Rendering Methods ====== 
 There exist various rendering models that can be used to render computer graphics. Nearly all of the rendering in games is using a sort of **ad-hoc rendering method**. These are rendering methods that contain parameters in the rendering equations that are **interlinked** and/or **unintuitive to use**. These game engines or rendering engines expose some kind of **specularity** value typically paired with some kind of **exponent** parameter. The specularity represents in these systems the strength of the specular reflections of light sources on a material. The expoonent on the other hand defines the shape of the specular reflection. A well known method is the Phong rendering in which the specular exponent is of a cosine form whereas the specularity is a percentage value between 0% and 100% of the light added as specular reflection. The main problem with these systems is that in reality the speculiarty and exponent values vary across the material for different **viewing directions** as well as different **lighting conditions**. One set of parameters tuned for one lighting condition does usually not work well at all for an entirely different lighting condition. This is due to the fact that for different lighting conditions these parameters have to adjusted. This is though neither feasible to do nor is it easy for the artist. What is the proper specular exponent to use for a model? And what is the correct specular reflection strength to use? Answering these questions for an artist is a problem in many cases. In the end these Ad-hoc rendering methods result in artificial renders and artists having to adjust lighting parameters whenever the lighting conditions change in a scene. There exist various rendering models that can be used to render computer graphics. Nearly all of the rendering in games is using a sort of **ad-hoc rendering method**. These are rendering methods that contain parameters in the rendering equations that are **interlinked** and/or **unintuitive to use**. These game engines or rendering engines expose some kind of **specularity** value typically paired with some kind of **exponent** parameter. The specularity represents in these systems the strength of the specular reflections of light sources on a material. The expoonent on the other hand defines the shape of the specular reflection. A well known method is the Phong rendering in which the specular exponent is of a cosine form whereas the specularity is a percentage value between 0% and 100% of the light added as specular reflection. The main problem with these systems is that in reality the speculiarty and exponent values vary across the material for different **viewing directions** as well as different **lighting conditions**. One set of parameters tuned for one lighting condition does usually not work well at all for an entirely different lighting condition. This is due to the fact that for different lighting conditions these parameters have to adjusted. This is though neither feasible to do nor is it easy for the artist. What is the proper specular exponent to use for a model? And what is the correct specular reflection strength to use? Answering these questions for an artist is a problem in many cases. In the end these Ad-hoc rendering methods result in artificial renders and artists having to adjust lighting parameters whenever the lighting conditions change in a scene.
  
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 ====== Example Materials ====== ====== Example Materials ======
-Images of some example materials can be found in the **[[http://rptd.ch/gallery/main.php?g2_itemId=1961|image gallery]]**.+Images of some example materials can be found in the **[[gamedev:pbr:examplematerials|Example Materials Preview]]**.
  
gamedev/pbr.1354665144.txt.gz · Last modified: 2012/12/04 23:52 by dragonlord