Ray Tracing in One Weekend (Rust)

An Abstract Class for Materials

If we want different objects to have different materials, we have a design decision. We could have a universal material type with lots of parameters so any individual material type could just ignore the parameters that don't affect it. This is not a bad approach. Or we could have an abstract material class that encapsulates unique behavior. I am a fan of the latter approach. For our program the material needs to do two things:

1. Produce a scattered ray (or say it absorbed the incident ray).
2. If scattered, say how much the ray should be attenuated.

This suggests the abstract class:

use crate::{hittable::HitRecord, prelude::*};

pub trait Material {
    fn scatter(&self, _r_in: Ray, _rec: HitRecord) -> Option<(Ray, Color)> {
        None
    }
}

Listing 58: [material.rs] The material class