Ray Intersection - NFHN Reader

Ray–Surface Intersection

An interactive geometry primer

A ray tracer renders images by casting rays from a camera through every pixel and finding where each ray hits a surface. This tool explores the core mathematical question: how do you compute that intersection?

Choose a geometry — sphere, cylinder, or torus — and explore it across three lenses:

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Theory

Derive the intersection polynomial step by step

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Intuition

Aim a ray interactively and watch the roots move

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Code

Edit live GLSL — see the shader render in real time