Ray tracing is a rendering technique used in computer graphics to simulate the way light interacts with objects in a scene. It involves tracing the path of rays of light as they travel through a virtual environment and interact with surfaces, materials, and light sources. The goal of ray tracing is to generate realistic images by accurately simulating the behavior of light, shadows, reflections, and refractions.
The process of ray tracing typically involves the following steps:
Ray generation: Rays are cast from the virtual camera (viewer's perspective) through each pixel of the image plane.
Intersection testing: The rays are traced through the scene, and intersection tests are performed to determine where the rays hit objects in the environment.
Shading: Once an intersection point is found, the renderer calculates the lighting at that point, considering factors such as the material properties, light sources, and the angle of the incident light.
Reflection and refraction: If a surface is reflective or refractive, additional rays are cast for reflections or refractions. This process can be recursive for multiple bounces.
Shadow rays: Shadow rays are cast from the intersection points toward light sources to determine whether a point is in shadow or illuminated.
Global illumination: To simulate indirect lighting, rays can be traced to capture the contribution of light bouncing off other surfaces in the scene.
Ray tracing can produce highly realistic images with accurate lighting effects, including realistic shadows, reflections, and refractions. However, it is computationally intensive and can require substantial processing power, especially for complex scenes and high-resolution images.
Ray tracing has gained popularity in the field of computer graphics, and advancements in hardware, such as the use of dedicated graphics processing units (GPUs) optimized for ray tracing, have made it more feasible for real-time applications, including video games and virtual reality.