3D Ray Tracing Transmission and Reflection Explanation

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Ray tracing is a fundamental technique in computer graphics that simulates how light travels through a scene. When a light ray encounters a surface, two primary phenomena occur: reflection, where the ray bounces off the surface, and transmission, where the ray passes through the surface into a different medium. Understanding these interactions is crucial for creating realistic rendered images.The law of reflection states that when a light ray strikes a surface, the angle of incidence equals the angle of reflection. Both angles are measured relative to the surface normal, which is a line perpendicular to the surface at the point of contact. This fundamental principle governs how mirrors work and is essential for calculating reflected rays in ray tracing algorithms.When light passes from one medium to another, such as from air into glass, it undergoes refraction. Snell's law describes this phenomenon mathematically. The law states that the product of the refractive index and the sine of the angle remains constant across the interface. When light enters a denser medium, it bends toward the normal, and the transmitted angle becomes smaller than the incident angle.In three-dimensional ray tracing, we visualize how rays interact with surfaces in space. Here we see a surface plane with an incident ray approaching from above. The normal vector points perpendicular to the surface. Upon hitting the surface, the ray splits into two components: the reflected ray bounces back into the original medium following the law of reflection, while the transmitted ray passes through the surface and refracts according to Snell's law. This 3D perspective helps us understand the spatial relationships between all vectors involved in the interaction.