pbrt/shared/src/lights/distant.rs

102 lines
2.8 KiB
Rust

use crate::core::geometry::{
Bounds3f, Normal3f, Point2f, Point3f, Point3fi, Ray, Vector3f, VectorLike,
};
use crate::core::interaction::{Interaction, InteractionBase, SimpleInteraction};
use crate::core::light::{LightBase, LightBounds, LightLiSample, LightSampleContext, LightTrait};
use crate::core::spectrum::SpectrumTrait;
use crate::spectra::{DenselySampledSpectrum, SampledSpectrum, SampledWavelengths};
use crate::utils::Ptr;
use crate::{Float, PI};
use num_traits::Float as NumFloat;
#[repr(C)]
#[derive(Clone, Copy, Debug)]
pub struct DistantLight {
pub base: LightBase,
pub lemit: Ptr<DenselySampledSpectrum>,
pub scale: Float,
pub scene_center: Point3f,
pub scene_radius: Float,
}
impl DistantLight {
pub fn sample_li_base(
&self,
ctx_p: Point3f,
lambda: &SampledWavelengths,
) -> (SampledSpectrum, Vector3f, Float, Point3f) {
let wi = self
.base
.render_from_light
.apply_to_vector(Vector3f::new(0., 0., 1.))
.normalize();
let p_outside = ctx_p + wi * 2. * self.scene_radius;
let li = self.scale * self.lemit.sample(lambda);
(li, wi, 1.0, p_outside)
}
}
impl LightTrait for DistantLight {
fn base(&self) -> &LightBase {
&self.base
}
fn phi(&self, lambda: SampledWavelengths) -> SampledSpectrum {
self.scale * self.lemit.sample(&lambda) * PI * self.scene_radius.sqrt()
}
fn sample_li(
&self,
ctx: &LightSampleContext,
_u: Point2f,
lambda: &SampledWavelengths,
_allow_incomplete_pdf: bool,
) -> Option<LightLiSample> {
let wi = self
.base
.render_from_light
.apply_to_vector(Vector3f::new(0., 0., 1.))
.normalize();
let p_outside = ctx.p() + wi * 2. * self.scene_radius;
let li = self.scale * self.lemit.sample(lambda);
let base = InteractionBase::new_boundary(p_outside, 0.0, self.base.medium_interface);
let intr = SimpleInteraction::new(base);
Some(LightLiSample::new(li, wi, 1., Interaction::Simple(intr)))
}
fn pdf_li(
&self,
_ctx: &LightSampleContext,
_wi: Vector3f,
_allow_incomplete_pdf: bool,
) -> Float {
0.
}
fn l(
&self,
_p: Point3f,
_n: Normal3f,
_uv: Point2f,
_w: Vector3f,
_lambda: &SampledWavelengths,
) -> SampledSpectrum {
todo!()
}
fn le(&self, _ray: &Ray, _lambda: &SampledWavelengths) -> SampledSpectrum {
todo!()
}
fn preprocess(&mut self, scene_bounds: &Bounds3f) {
let (center, radius) = scene_bounds.bounding_sphere();
self.scene_center = center;
self.scene_radius = radius;
}
fn bounds(&self) -> Option<LightBounds> {
None
}
}