ObjectSdf

interface ObjectSdf

import type { ObjectSdf } from '@driftengine/assets';

In depth

Indirect light needs to ask what is in a direction, and a triangle list cannot answer that cheaply. A ray against a mesh is a traversal; a ray against a distance field is a march that steps by the field's own value and converges in a handful of steps, because the value is a safe step. That is the whole of sphere tracing, and the one property it rests on is that the field is a distance — gradient of unit length — rather than merely something with the right sign. sdf.test.ts measures that property rather than assuming it.

Per object rather than per world, because the world moves: globalField.ts composes these into a field around the camera each frame, and an instance that rotates or streams in has to bring its field with it. A world-scale bake would have to be redone whenever anything moved.

Properties