100 lines
3.1 KiB
Rust
100 lines
3.1 KiB
Rust
use crate::core::geometry::{
|
|
Bounds3f, Normal3f, Point2f, Point3f, Point3fi, Ray, Vector3f, VectorLike,
|
|
};
|
|
use crate::core::interaction::{Interaction, InteractionBase, InteractionTrait, SimpleInteraction};
|
|
use crate::core::light::{LightBase, LightBounds, LightLiSample, LightSampleContext, LightTrait};
|
|
use crate::core::spectrum::SpectrumTrait;
|
|
use crate::spectra::{DenselySampledSpectrum, SampledSpectrum, SampledWavelengths};
|
|
use crate::{Float, PI, Ptr, Transform};
|
|
use num_traits::Float as NumFloat;
|
|
|
|
#[repr(C)]
|
|
#[derive(Clone, Copy, Debug)]
|
|
pub struct SpotLight {
|
|
pub base: LightBase,
|
|
pub iemit: Ptr<DenselySampledSpectrum>,
|
|
pub scale: Float,
|
|
pub cos_falloff_start: Float,
|
|
pub cos_falloff_end: Float,
|
|
}
|
|
|
|
impl SpotLight {
|
|
pub fn i(&self, w: Vector3f, lambda: &SampledWavelengths) -> SampledSpectrum {
|
|
let cos_theta = w.z(); // assuming normalized in light space
|
|
let falloff = crate::utils::math::smooth_step(
|
|
cos_theta,
|
|
self.cos_falloff_end,
|
|
self.cos_falloff_start,
|
|
);
|
|
falloff * self.scale * self.iemit.sample(lambda)
|
|
}
|
|
}
|
|
|
|
impl LightTrait for SpotLight {
|
|
fn base(&self) -> &LightBase {
|
|
&self.base
|
|
}
|
|
|
|
fn sample_li(
|
|
&self,
|
|
ctx: &LightSampleContext,
|
|
_u: Point2f,
|
|
lambda: &SampledWavelengths,
|
|
_allow_incomplete_pdf: bool,
|
|
) -> Option<LightLiSample> {
|
|
let pi = self
|
|
.base
|
|
.render_from_light
|
|
.apply_to_interval(&Point3fi::default());
|
|
let p: Point3f = pi.into();
|
|
let wi = (p - ctx.p()).normalize();
|
|
let w_light = self.base.render_from_light.apply_inverse_vector(-wi);
|
|
let li = self.i(w_light, lambda) / p.distance_squared(ctx.p());
|
|
|
|
let base = InteractionBase::new_boundary(p, 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.
|
|
}
|
|
|
|
#[cfg(not(gpu))]
|
|
fn phi(&self, lambda: SampledWavelengths) -> SampledSpectrum {
|
|
self.scale
|
|
* self.iemit.sample(&lambda)
|
|
* 2.
|
|
* PI
|
|
* ((1. - self.cos_falloff_start) + (self.cos_falloff_start - self.cos_falloff_end) / 2.)
|
|
}
|
|
|
|
fn preprocess(&mut self, _scene_bounds: &Bounds3f) {}
|
|
|
|
fn bounds(&self) -> Option<LightBounds> {
|
|
let p = self
|
|
.base
|
|
.render_from_light
|
|
.apply_to_point(Point3f::default());
|
|
let w = self
|
|
.base
|
|
.render_from_light
|
|
.apply_to_vector(Vector3f::new(0., 0., 1.))
|
|
.normalize();
|
|
let phi = self.scale * self.iemit.max_value() * 4. * PI;
|
|
let cos_theta_e = (self.cos_falloff_end.acos() - self.cos_falloff_start.acos()).cos();
|
|
Some(LightBounds::new(
|
|
&Bounds3f::from_points(p, p),
|
|
w,
|
|
phi,
|
|
self.cos_falloff_start,
|
|
cos_theta_e,
|
|
false,
|
|
))
|
|
}
|
|
}
|