pbrt/src/lights/distant.rs

94 lines
2.7 KiB
Rust

use crate::core::light::lookup_spectrum;
use crate::core::spectrum::spectrum_to_photometric;
use crate::core::texture::FloatTexture;
use crate::utils::{Arena, FileLoc, ParameterDictionary};
use anyhow::Result;
use shared::core::geometry::{Point3f, VectorLike};
use shared::core::light::{Light, LightBase, LightType};
use shared::core::medium::{Medium, MediumInterface};
use shared::core::shape::Shape;
use shared::core::spectrum::Spectrum;
use shared::core::texture::SpectrumType;
use shared::lights::DistantLight;
use shared::spectra::RGBColorSpace;
use shared::utils::{Ptr, Transform};
use shared::Float;
trait CreateDistantLight {
fn new(render_from_light: Transform, le: Spectrum, scale: Float) -> Self;
}
impl CreateDistantLight for DistantLight {
fn new(render_from_light: Transform, le: Spectrum, scale: Float) -> Self {
let base = LightBase::new(
LightType::DeltaDirection,
render_from_light,
MediumInterface::empty(),
);
let lemit = lookup_spectrum(&le);
Self {
base,
lemit: Ptr::from(&*lemit),
scale,
scene_center: Point3f::default(),
scene_radius: 0.,
}
}
}
pub fn create(
render_from_light: Transform,
_medium: Option<Medium>,
parameters: &ParameterDictionary,
_loc: &FileLoc,
_shape: &Shape,
_alpha_text: &FloatTexture,
colorspace: Option<&RGBColorSpace>,
_arena: &Arena,
) -> Result<Light> {
let default_cs = crate::spectra::default_colorspace();
let cs = colorspace.unwrap_or(&default_cs);
let l = parameters
.get_one_spectrum(
"L",
Some(Spectrum::Dense(cs.illuminant)),
SpectrumType::Illuminant,
)
.unwrap();
let mut scale = parameters.get_one_float("scale", 1.)?;
let from = parameters.get_one_point3f("from", Point3f::new(0., 0., 0.))?;
let to = parameters.get_one_point3f("to", Point3f::new(0., 0., 1.))?;
let w = (from - to).normalize();
let (v1, v2) = w.coordinate_system();
let m: [Float; 16] = [
v1.x(),
v2.x(),
w.x(),
0.,
v1.y(),
v2.y(),
w.y(),
0.,
v1.z(),
v2.z(),
w.z(),
0.,
0.,
0.,
0.,
1.,
];
let t = Transform::from_flat(&m).expect("Could not create transform for DistantLight");
let final_render = render_from_light * t;
scale /= spectrum_to_photometric(l);
// Adjust scale to meet target illuminance value
let e_v = parameters.get_one_float("illuminance", -1.)?;
if e_v > 0. {
scale *= e_v;
}
let specific = DistantLight::new(final_render, l, scale);
Ok(Light::Distant(specific))
}