libtrace

PyTrace (core)

pytrace_core

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Direct dependencies

rand

threadpool

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Originally inspired by Ray Tracing in One Weekend (Peter Shirley).

This library cannot be executed as-is, but it can provide tools that pytrace can then use.

It is also possible to import it from a Rust script: see rstrace for a concrete example.

Creating a new complex object

Usually a scene would be created from pytrace or rstrace, but if one wishes to create a new generalizable object, then this is the right crate to modify.

To do so, it is recommended to create a new file in the composite module :

• Create a new file composite/<object>.rs
• Implement <object> by providing a build method (more information below)
• Integrate the new object with the rest of the program by adding the two lines pub mod <object>; and pub use <object>::<Object>; in composite/mod.rs (see examples)

What already existed ?

Of course, this project bears some resemblance with the original Ray tracing in one Weekend:

• The name of many types and functions are the same: internal::hitable::schlick, internal::camera::Camera::get_ray, internal::vec3::Vec3, internal::ray::Ray, internal::hitable::Hit, internal::hitable::Texture::Lambertian.
• Some ideas were kept: overloading std::ops::Mul for internal::rgb::RGB, initial internal::camera::Camera abstraction.
• Some chunks of code have been translated to Rust almost verbatim: internal::primitives::Sphere::hit, internal::hitable::scatter.

Many other similarities were partially or completely rewritten halfway into the project.

The hit implementations for many objects were inspired by or debugged with the help of a wide variety of websites: internal::hitable::{EmptyCylinder, EmptyCone, Triangle} were implemented after comparing the implementations of intersection with a ray from at least a dozen sources, most of which had made widely different design choices and were hard to adapt.

internal::hitable::{InfinitePlane, Disc} are original implementations, internal::hitable::Parallelogram was adapted from internal::hitable::Triangle, and all of the other are merely wrappers.

What's new ?

• All composite objects (composite::axes::Axes, composite::cradle::NewtonCradle, composite::die::Die, composite::erlenmeyer::Erlenmeyer, composite::molecules::Molecules)
• The intersection/removal mechanism implemented in internal::hitable::Interaction is completely original
• Although the first versions of the internal::hitable::Texture::Dielectric branch of internal::hitable::scatter were copied, later versions were fully remade from scratch with a completely different, which (unlike the original one) correctly deals with dielectric/dielectric interfaces (see internal::world::{scatter, World::caracteristics})
• internal::hitable::HitRecord was also fully revised
• The internal::sky::Sky texture
• Brand new internal::camera::Camera abstraction: instead of (look_from, look_at, upwards, field_of_view_angle, aspect_ratio), it is much easier to fine-tune a view with (look_at, angle_around_target, angle_above_target, distance_to_target, tilt, field_of_view_angle, aspect_ratio)
• The original version did not support multithreading
• All scenes visible in ../img/ are of my own creation