What is PBR?

What does PBR stand for?

PBR stands for Physically Based Rendering.
PBR is a set of rendering techniques that simulates the processes of physical light transport through a medium.

What is Physically Based Rendering?

The term “physically based rendering” (PBR) is a relatively recent phenomenon. It refers to a range of techniques that allow artists to produce realistic-looking images. PBR took shape in computer graphics in the late 1980s and early 1990s, when it became obvious that conventional computer graphics techniques were obsolete. Traditional computer graphics, known as “pseudo-realistic” or “pretend,” relied on light and color that was too bright and too saturated. The result was unrealistic-looking images.

The technique known as “volume rendering” (VR) was an early attempt to produce more realistic images. VR models objects by calculating their geometry, assigning them material properties (like reflectivity), and setting their lighting. VR worked well for simple objects, but its results degraded when objects were large or complex.

In the 1990s, researchers at the University of Illinois at Urbana-Champaign developed a new type of computer graphics. Using the principles of physics, they combined VR with other methods, making realistic-looking images possible even for complex objects. PBR became the name of this collection of techniques. PBR models objects by calculating their geometry, assigning them material properties, and setting their lighting. PBR is the basis for physically based rendering, which, although technically complicated, is simple enough for artists to use.
In PBR, color, reflectance, and specularity are the three most important factors affecting how objects look.

Different maps in PBR Textures by A23D
Various PBR Maps

The PBR workflow is different to traditional rendering workflows in that it:

  • maps real-world physical properties to computer properties
  • considers objects and materials in the real world, not just how they will appear on a screen
  • models the real-world physical properties of materials
  • predicts how materials will look to the human eye

The PBR workflow is physically based because it relies on real-world physical properties that can be determined with measurements and precise formulas. It is computationally efficient because it relies on efficient algorithms that do not require detailed knowledge of how materials behave in the real world. It is realistic because it uses real-world physical constants to represent materials. It was developed by the computer graphics community to improve realism in 3D graphics.

What are the benefits of PBR?

PBR is a set of features and attributes that are used to render and texture 3D models. It is the standard in current 3D modeling software such as 3ds Max and Maya. This workflow is sometimes referred to as the “high-end” workflow.

  • PBR allows artists to create better looking, more photorealistic images. PBR gives artists more control over the materials of their model. PBR includes reflection, refraction, and diffuse lighting.
  • PBR includes other material attributes such as roughness, specular highlights, metallic, glossiness, and self-illumination.
  • PBR allows artists to create detailed textures.
  • PBR allows artists to create realistic lighting effects.
  • PBR allows artists to share textures between different software packages.
  • PBR is a feature of the current generation of 3D software. PBR is gaining popularity, as more and more artists begin to use it. Some 3D artists avoid PBR software because they feel it is too hard to learn.

PBR isn’t particularly new. The images of cars and buildings that you’ve seen on the Internet were made with PBR rendering. PBR is simply a set of features that has only recently become popular. PBR is a workflow; it is a set of techniques that artists use to render and texture their models.

Principles based rendering (PBR) is a rendering technique that uses physical based materials, rather than traditional shaders, to model the appearance of surfaces. Originally developed by Nvidia, PBR is now being adopted by most major game engines.
PBR differs from traditional shader-based rendering in that it models the interactions between light and a surface, allowing artists to define how light interacts with a surface’s color, specular highlights, normals, and reflections.

Who is using PBR?

Traditionally, many game developers have used traditional shaders to model the appearance of surfaces; these define the material’s reflections, glossiness, and diffuse properties, but not the way that light interacts with a surface. PBR allows artists to define how those interactions occur, and it creates a consistent, standard appearance for models, materials, and textures.

PBR’s standard appearance is useful for simulating materials that we usually encounter in real life: metal, plastic, glass, and cloth. PBR allows for more realistic lighting of these surfaces, and it is also more efficient because it removes the need for many lighting calculations. PBR is most suited to rendering environments made up of large, complex geometries, such as terrain. However, PBR can be used for both indoor and outdoor environments, and for materials that range from simple to complex.

Many artists, and even some studios, believe that PBR is just another buzz word. However, PBR is a relatively new term that stands for Physically Based Rendering. PBR techniques have been around for a while, with many software packages now offering PBR rendering. PBR is a branch of computer graphics that tries to model reality as accurately as possible.

PBR, or PBR rendering, attempts to accurately model light, color, the surfaces of objects, and material properties. The lighting that falls on a PBR model can have interpretations for the real world. For example, light falling on a mirror can be reflected. Light falling on a shiny metal surface will reflect if the surface is wet. Light falling on a wet surface will have a color that is less vivid than light falling on a dry surface.

PBR rendering is also now used in game engines, which render real-time graphics for video games. A game engine can render all the textures needed to achieve a photorealistic image.
PBR rendering is also now used in game engines, which render real-time graphics for video games. A game engine can render all the textures needed to achieve a photorealistic image.