Computer Graphics Questions Medium
Global illumination refers to the simulation of realistic lighting effects in computer graphics by considering the interaction of light with various surfaces and objects in a scene. It aims to accurately reproduce the way light behaves in the real world, taking into account factors such as reflections, refractions, and indirect lighting.
In computer graphics, global illumination algorithms are used to calculate the distribution of light in a scene, considering both direct and indirect illumination. Direct illumination refers to the light that directly reaches a surface from a light source, while indirect illumination refers to the light that is bounced off surfaces and objects in the scene, creating secondary lighting effects.
Global illumination algorithms typically use ray tracing or radiosity techniques to calculate the interaction of light with surfaces. Ray tracing involves tracing rays of light from the camera through each pixel and simulating their interaction with objects in the scene. This allows for accurate calculations of reflections, refractions, and shadows.
Radiosity, on the other hand, focuses on the indirect illumination by considering the exchange of light energy between surfaces. It divides the scene into small patches and calculates the amount of light energy transferred between them, taking into account factors such as surface color, reflectivity, and light sources.
By considering both direct and indirect illumination, global illumination algorithms can produce more realistic and visually appealing images. They can accurately capture the subtle interplay of light and shadow, resulting in scenes that closely resemble real-world lighting conditions. However, global illumination algorithms can be computationally expensive and time-consuming, requiring significant computational resources to achieve high-quality results.