valaistusmalleja

Valaistusmalleja, or lighting models, are mathematical representations used in various technical and artistic fields to simulate how light interacts with surfaces and scenes. Their purpose is to predict illumination, shading, and color transfer under different conditions. In computer graphics, lighting models provide deterministic approximations that can be rendered in real time or in high‑quality offline rendering. In architecture and interior design, lighting models help visualise how natural and artificial light will appear in a space, aiding in design decisions. Photographers and cinematographers also rely on lighting models to anticipate how camera exposure, reflectors, and modified light will affect subjects.

Early lighting models, such as the diffuse and specular reflection equations, were based on the Lambertian assumption for matte surfaces and the ideal mirror for perfect specular highlights. Successive models introduced more realism: the Phong model added an adjustable shininess exponent, while Blinn‑Phong refined specular lobe computation. Physically‑based rendering pushed the field further with microfacet theory. Cook‑Torrance and GGX models account for surface roughness, Fresnel effects, and energy conservation. These sophisticated models underpin modern rendering engines like Unreal Engine and Blender Cycles for realistic lighting.

In engineering, lighting models also support numerical simulation of daylighting, glare assessment, and illumination calculations per national standards. In animation, artists manipulate lighting models for stylistic consistency and mood creation. The continuous development of lighting models balances computational efficiency with visual fidelity, driving advances in both digital media and technical design.