Raymarching distance fields tutorial

[JeGX]

Rendering an image involves determining the colour of every pixel in the image, which requires figuring out what surface lies behind the pixel in the world, and then 'shading' it to compute a final colour.

Current generation GPUs take triangle meshes as input, rasterise them into pixels (called fragments before they're drawn to a display), and then shade them to calculate their contribution to the image. While this pipeline is currently ubiquitous, it is also complicated and not necessarily the best way to learn graphics.

An alternative approach is to cast a ray through each pixel and intersect it with the surfaces in the scene, and then compute the shading.

This course introduces one technique for raycasting through 'distance fields'. A distance field is a function that returns how close a given point is to the closest surface in the scene. This distance defines the radius of a sphere of empty space around each point. Signed distance fields (SDFs) are distance fields that are defined both inside and outside objects; if the queried position is 'inside' a surface, its distance will be reported as negative, otherwise it will be positive.

Link: https://github.com/ajweeks/RaymarchingWorkshop