## Lumo
[](https://crates.io/crates/lumo)
[](https://docs.rs/lumo)
[](https://coveralls.io/github/ekarpp/lumo)
Lumo is a CPU based multithreaded rendering engine. Made with the goal of learning Rust and physically based rendering :) The renderer is designed to be as modular as possible such that adding new features or algorithms is straightforward.
### Features
* Area light sampling
* Path tracing with next event estimation
* [Cook-Torrance microfacet BSDF](https://doi.org/10.1145/357290.357293) with [Beckmann and GGX](http://dx.doi.org/10.2312/EGWR/EGSR07/195-206) normal distribution functions
* [Multiple importance sampling from VNDF for GGX](https://jcgt.org/published/0007/04/01/)
* [Disney diffuse BRDF](https://disneyanimation.com/publications/physically-based-shading-at-disney/) with [energy normalization used in Frostbite engine](https://seblagarde.files.wordpress.com/2015/07/course_notes_moving_frostbite_to_pbr_v32.pdf)
* .OBJ file parsing
* Surface area hierarchy based kD-trees
### Usage
Once the repository is cloned, the `examples/` folder contains scenes. To run the `hello_sphere.rs` example execute the command:
```bash
cargo run --example hello_sphere
```
The renderer can be configured either through its setter methods or partially through the CLI:
```
Usage: hello_sphere [-s <samples>] [-t <threads>] [-d] [-b]
Optional CLI configuration of renderer. Renderer setter methods have priority.
Options:
-s, --samples number of samples per pixel (defaults to 1)
-t, --threads number of threads used (defaults to all)
-d, --direct use direct light integrator instead of path tracing.
-b, --bdpt use bidirectional path tracing instead of path tracing.
--help display usage information
```
#### Using the API
The `hello_sphere.rs` example is written as follows:
```rust
use glam::DVec3;
use lumo::tracer::*;
use lumo::*;
fn main() -> Result<(), png::EncodingError> {
let camera = Camera::default(1280, 720);
let mut scene = Scene::default();
scene.add(Plane::new(
DVec3::NEG_Y,
DVec3::Y,
Material::diffuse(Texture::Solid(srgb_to_linear(190, 200, 210))),
));
scene.add_light(Sphere::new(
8.0 * DVec3::Y + 1.5 * DVec3::NEG_Z,
4.0,
Material::Light(Texture::Solid(srgb_to_linear(255, 255, 255))),
));
scene.add(
Sphere::new(
DVec3::ZERO,
1.0,
Material::diffuse(Texture::Solid(srgb_to_linear(0, 0, 255))),
)
.scale(0.3, 0.3, 0.3)
.translate(0.0, -0.7, -1.5),
);
let mut renderer = Renderer::new(scene, camera);
renderer.set_samples(36);
renderer.render().save("hello.png")
}
```
### References
* [Physically Based Rendering](https://www.pbr-book.org/)
* [Ray Tracing in One Weekend](https://raytracing.github.io/)
* [Moving Frostbite to Physically Based Rendering](https://seblagarde.files.wordpress.com/2015/07/course_notes_moving_frostbite_to_pbr_v32.pdf)
* [Eric Veach's PhD Thesis](http://graphics.stanford.edu/papers/veach_thesis/)
* [ekhzang/rpt](https://github.com/ekzhang/rpt)
### Gallery
