Säteenseurantatekniikkaa

Säteenseurantatekniikkaa, or ray tracing in English, is a computer graphics rendering technique used to produce highly realistic images. It simulates the physical behavior of light by tracing the path of individual light rays as they travel from a light source, bounce off objects in a scene, and eventually reach the virtual camera.

The core principle of ray tracing involves calculating the color of each pixel on the screen by following a ray backward from the camera into the scene. When this ray intersects an object, the algorithm determines how light interacts with that object's surface. This interaction can involve reflection, refraction (how light bends when passing through transparent materials like glass or water), and absorption.

For each intersection, new rays are cast to simulate these effects. Reflected rays are sent in the direction of reflection, refracted rays follow the path of light passing through, and shadow rays are cast towards light sources to determine if the surface is illuminated or in shadow. This process is repeated recursively for each new ray until a ray either hits a light source, escapes the scene, or reaches a predefined recursion depth.

While ray tracing can produce incredibly lifelike results, including accurate shadows, reflections, and refractions, it is computationally intensive. This is because the number of rays that need to be traced can be enormous, especially in complex scenes with many light sources and reflective surfaces. Traditionally, this has limited its use to offline rendering for movies and architectural visualizations. However, advancements in hardware, such as dedicated ray tracing cores in modern GPUs, are making real-time ray tracing increasingly feasible for video games and interactive applications.