Struct rustic_zen::scene::Light

pub struct Light<R: Rng> {
    pub location: SamplerPoint<R>,
    pub power: Sampler<f64, R>,
    pub polar_distance: Sampler<f64, R>,
    pub polar_angle: Sampler<f64, R>,
    pub ray_angle: Sampler<f64, R>,
    pub wavelength: Sampler<f64, R>,
}

Definition of a Light Source in for a scene.

Examples

Manually make a warm white small round light:

use rustic_zen::prelude::*;

let l = Light {
    power: Sampler::new_const(1.0),
    location: (512.0, 512.0).into(),
    polar_angle: Sampler::new_const(0.0),
    polar_distance: Sampler::new_const(0.0),
    ray_angle: Sampler::new_range(360.0, 0.0),
    wavelength: Sampler::new_blackbody(5800.0),
};

let scene = Scene::new(1920,1080).with_light(l);

Fields

location: SamplerPoint<R>

coordinates of the light in the scene.

power: Sampler<f64, R>

Brightness of this light relative to other lights in the scene. This is a proportion of the total power of all lights of the scene. So if you have 50 lights of power 1 each light has a 1 in 50 chance of being selected to spawn a ray. However adding 1 more light with power 10 will lower the existing lights to 1 in 60 and the new light will have 1 in 6. once used this is quite intuitive, the power will change the relative brightness of the lights, without changing the overall brightness of the scene.

polar_distance: Sampler<f64, R>

distance from location that the light ray will spawn, this can be used to create lights that are larger than a single pixel Fixing this to a single value will create a ring where the rays spawn, using a range of 0 - size will create a filled circle of spawn points.

polar_angle: Sampler<f64, R>

combined with polar_distance this creates a vector that is added to location to generate the final point the light ray will spawn. Using a range of 360 - 0 will create a full circle, constraining this can create an arc.

ray_angle: Sampler<f64, R>

Angle at which the spawned ray will fly away from the light. This is in absolute screen angle (0 is right). Setting this to a range of 0 - 360 will create an omidirectional light, constraining this range creates a more cone like light. Constraining it all the way to a single fixed value will create a laser. Using a polar_distance > 0 is recomended if the ray_angle is constrained to a single value, as a ray 1 pixel wide can be hard to see.

wavelength: Sampler<f64, R>

Wavelength of spawned ray in nanometers. Only values of 380.0 - 700.0 are visible. Using a fixed value will create a strongly coloured light of that wavelength. To create natural looking white lights use Sampler::new_blackbody(<temp>). Blackbody tempratures of 1,000 to 10,000 kelvin are visible.

Warning

Rays are sampled until a visible wavelength is found, this is an optimisation, selecting a fixed value or range of values outside of the visible spectrum can crash the render. So can selecting extreme blackbody tempratures.

Implementations

impl<R> Light<R>

where R: Rng,

pub fn new<A, B, C, D, E, F>( location: A, power: B, polar_distance: C, polar_angle: D, ray_angle: E, wavelength: F ) -> Self

where A: Into<SamplerPoint<R>>, B: Into<Sampler<f64, R>>, C: Into<Sampler<f64, R>>, D: Into<Sampler<f64, R>>, E: Into<Sampler<f64, R>>, F: Into<Sampler<f64, R>>,

Helper function to create a Light quickly, using common casts available in the library.

Example Usage

Create the same small round light as above using the helper:

use rustic_zen::prelude::*;

let l = Light::new((512.0,512.0), 1.0, 0.0, 0.0, (360.0, 0.0), Sampler::new_blackbody(5800.0));

let scene = Scene::new(1920,1080).with_light(l);

Trait Implementations

impl<R: Clone + Rng> Clone for Light<R>

fn clone(&self) -> Light<R>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.