The process of rendering refers to the procedures implemented in order to generate either a realistic (physically based rendering or PBR) or non-realistic (non-photorealistic rendering or NPR) image from input data. The basic meaning of the word refers to the tasks an artist would perform when completing a piece, with finished artwork also referred to as “rendering”. However, the meaning has shifted nowadays to refer to the generation of a video or image from a very precise description using digital functionality.
The software that performs the action is known as a rendering engine, rendering system, or graphics engine, with a distinction being made between real-time rendering (where the image is generated and displayed right away) and offline rendering (in which the content is created for later viewing). The emergence of the Render Network has led users to check the latest Render price as well in order to ensure the best conditions for their jobs, preferences, and RNDR tokens. But what exactly is the difference between the different types of rendering, and what should users know about each?
Physically based rendering
Physically based rendering is a computer graphics approach that renders images in a manner that models textures, surfaces, and light in a way that mimics the optics of the real world. It is also known as physically based lighting and physically based shading, as it aims to achieve photorealism. The idea is to have the art look as realistic as possible, but PBR itself is more of a concept than a strictly defined set of rules. However, there are still several rules that must be followed to achieve the best results.
For instance, instead of differentiating between reflective and non-reflective surfaces, with PBR, everything has a certain degree of shine. That means even matte surfaces, which are typically depicted as “flat” in an artwork, actually reflect some light in reality. Many metals and liquids also tend to reflect much more than is often depicted in art. Photogrammetry is another concept that is generally integrated into physically based rendering. It refers to the science of obtaining trustworthy information and minute details about physical objects and environments via recording and then measuring and interpreting these visual records and patterns.
In PBR, photogrammetry is used to study and replicate various phenomena, including reflectivity, albedo, and gloss. All kinds of physical properties can be determined in this manner, and seeing the ways in which they behave in real life is naturally very helpful for an artist who wants to represent these processes as accurately as possible. Physically based rendering also emphasizes microfacets, the bright spots of light that appear on any object when it is directly illuminated. Also known as Specular highlights, they are a very important part of 3D computer graphics as they offer strong visual cues for the shape of objects and their location with respect to the light sources.
As a result, PBR contains additional textures and mathematical models intended for small-scale specular highlights and specular occlusion to create smoothness and roughness, as well as reflectivity and specular maps. Bidirectional scattering distribution is used to calculate the visible light reflected at a certain time on the surfaces, with the approach focusing on translucency and transparency, reflection, diffusion, subsurface scattering, metallicity, and Fresnel reflections. PBR is used in volume renderings (the collection of techniques used to display 2D projections of 3D sampled data sets, most frequently scalar fields), within areas of research like caustics, light scattering, day-night cycles, elevation, weather and sky conditions, and the angular distance from the Sun, Moon, or other orbital objects.
Non-photorealistic rendering
Contrary to the traditional computer graphics that focus on photorealism, NPR seeks to enable a broad variety of styles for digital art. It is inspired by paintings and drawings, but also by cartoons and technical illustrations. It has appeared in films and video games in the form of cel-shading as well as in architectural illustrations, experimental animation, and scientific visualization projects. 3D NPR is most commonly used in this regard, as it is employed in visual media. The output is almost always a 3D model that has been altered from the original input to portray a different style.
The geometry is generally identical to the original one, with only the material applied to the surface being modified. With the increasing availability of GPUs (such as the ones powering Render token), shaders can now apply non-photorealistic rendering to rasterized images that can then be displayed on screen. Most NPR methods are designed to create the illusion of two-dimensional scenes, utilizing techniques such as Gooch shading (widely employed in technical illustrations) and cel shading. Occluding and suggestive contours are both used to create the stylized outlines of 3D models.
Cartoon rendering gives 3D graphics a flat appearance, hence its name. The defining characteristic is the use of highly distinct shading hues instead of smooth gradients to produce a look that is reminiscent of both animated motion pictures and series, as well as comic books. 3D objects and 2D hand-animated elements are blended together using this technique, as it preserves a consistent look. NPR methods and processes have been used to create several well-known feature films, including Tarzan and Spider-Man: Into the Spider-Verse and Across the Spider-Verse.
The bottom line
There are several differences between PBR and NPR, with the former aiming for accuracy and realism while the latter is focused on artistry, stylized visuals, and the ability to deliver a wide range of expressions. PBR is focused on models of light and material textures that are physically accurate and realistic, while NPR employs artistic effects. Ultimately, they both deliver intricate and complex images, only in different ways.
Tools like the Render Network are very important for creators, as they allow for the renting of idle graphics power for various projects. The RNDR token powers this ecosystem, enabling fast, transparent, and entirely decentralized transactions between node operators and creators. Using decentralized rendering is also significantly more cost-effective than standard GPU services, eliminating concerns related to scalability and pricing.
Proof-of-render is also implemented in order to guarantee verified outputs so that only completed and validated tasks are rewarded. This means that blockchain-level trust and transparency are maintained at all times.
Rendering is not a new process, as it has existed under several different forms throughout the years. It is currently a highly technological and scientific procedure as well as an artistic one, and depending on what the artist hopes to achieve, different types of it can be used.
