Abstract typography art by Paul Threadgold.
|Anti-Aliasing||Anti-aliasing, or AA, is the technique of minimizing the distortion artifacts (known as aliasing) when representing a high-resolution image at a lower resolution. In the case of rendering, aliasing often manifests itself as heavily jagged or pixelated edges in areas of high contrast, such as the boundaries of light sources.|
|AOV||AOV stands for Arbitrary Output Value. An AOV is each of the compositing channels supported by the render engine (e.g., alpha channel, AO, specular component, ...). Please read the page about compositing AOVs for a list of the AOVs supported by Arion.|
|Firefly||Pixel that gets overbright and which does not dissolve over time, staying as a speckle in the final render. Fireflies are usually caused by hard integration paths where unbiased rendering is weak, or by anomalies in the modeling or light setup. Please read the page about Efficient modeling for some tips on how to avoid the apparison of fireflies.|
|G-Buffer||A Graphics Buffer is a framebuffer where pixels can store different layers of information beyond an RGB color. In Arion, the framebuffer is always a G-Buffer where the user can enable or disable a number of AOVs, and which can be exported into a single multi-layered OpenEXR image.|
|Importance Sampling||IS is a variance reduction technique that can be used in the Monte Carlo method. The idea behind IS is that certain values of the input random variables have more impact on the final render than others. By emphasizing thoseimportant values by sampling them more frequently, and compensating their contribution by the extra sampling frequency, then the estimator variance can be reduced. Arion makes use of IS in many situations. For example, IS is applied to emitter lighting, so the strongest emitters are sampled more often than the weakest ones.|
|Media Traversal Stack||When a light path travels through the scene, it may cross different participating media, such as fog or dielectrics. Arion keeps track of what media light paths are in, and for how long they have traveled in each media. This structure, called Media Traversal Stack is used for phenomena such as refraction, dielectric absorption, and SSS.|