sädejäljitykseen

Sädejäljitykseen, or ray tracing in English, is a rendering technique used in computer graphics to produce highly realistic images. It works by simulating the physical behavior of light. Instead of just drawing what is seen from the camera's perspective, ray tracing follows the path of individual light rays as they bounce off surfaces, refract through transparent objects, and interact with light sources.

For each pixel on the screen, a virtual ray is cast from the camera into the scene. This ray is then traced as it travels through the virtual environment. When the ray encounters an object, its behavior is determined by the properties of that object and the light hitting it. The ray might be reflected, absorbed, or pass through. If it reflects, a new ray is spawned in the reflection direction, and this process continues recursively. Similarly, if the ray hits a light source, its contribution to the pixel's color is calculated.

This complex simulation allows for accurate representation of various lighting effects that are difficult to achieve with simpler rendering methods. These effects include realistic shadows, reflections on glossy surfaces, refractions in glass and water, and global illumination, where light bounces indirectly off surfaces to illuminate other parts of the scene. While computationally intensive, ray tracing is a powerful tool for creating photorealistic visuals in applications like video games, animated films, and architectural visualization.