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use std::sync::Arc;
use crate::core::interaction::SurfaceInteraction;
use crate::core::material::{Material, TransportMode};
use crate::core::microfacet::{MicrofacetDistribution, TrowbridgeReitzDistribution};
use crate::core::paramset::TextureParams;
use crate::core::pbrt::{Float, Spectrum};
use crate::core::reflection::{
Bsdf, Bxdf, Fresnel, FresnelDielectric, LambertianReflection, LambertianTransmission,
MicrofacetReflection, MicrofacetTransmission,
};
use crate::core::texture::Texture;
pub struct TranslucentMaterial {
pub kd: Arc<dyn Texture<Spectrum> + Sync + Send>,
pub ks: Arc<dyn Texture<Spectrum> + Sync + Send>,
pub roughness: Arc<dyn Texture<Float> + Sync + Send>,
pub reflect: Arc<dyn Texture<Spectrum> + Sync + Send>,
pub transmit: Arc<dyn Texture<Spectrum> + Sync + Send>,
pub bump_map: Option<Arc<dyn Texture<Float> + Send + Sync>>,
pub remap_roughness: bool,
}
impl TranslucentMaterial {
pub fn new(
kd: Arc<dyn Texture<Spectrum> + Send + Sync>,
ks: Arc<dyn Texture<Spectrum> + Send + Sync>,
roughness: Arc<dyn Texture<Float> + Sync + Send>,
reflect: Arc<dyn Texture<Spectrum> + Send + Sync>,
transmit: Arc<dyn Texture<Spectrum> + Send + Sync>,
bump_map: Option<Arc<dyn Texture<Float> + Sync + Send>>,
remap_roughness: bool,
) -> Self {
TranslucentMaterial {
kd,
ks,
roughness,
reflect,
transmit,
bump_map,
remap_roughness,
}
}
pub fn create(mp: &mut TextureParams) -> Arc<Material> {
let kd = mp.get_spectrum_texture("Kd", Spectrum::new(0.25 as Float));
let ks = mp.get_spectrum_texture("Ks", Spectrum::new(0.25 as Float));
let reflect = mp.get_spectrum_texture("reflect", Spectrum::new(0.5 as Float));
let transmit = mp.get_spectrum_texture("transmit", Spectrum::new(0.5 as Float));
let roughness = mp.get_float_texture("roughness", 0.1 as Float);
let bump_map = mp.get_float_texture_or_null("bumpmap");
let remap_roughness: bool = mp.find_bool("remaproughness", true);
Arc::new(Material::Translucent(Box::new(TranslucentMaterial::new(
kd,
ks,
roughness,
reflect,
transmit,
bump_map,
remap_roughness,
))))
}
pub fn compute_scattering_functions(
&self,
si: &mut SurfaceInteraction,
mode: TransportMode,
_allow_multiple_lobes: bool,
_material: Option<Arc<Material>>,
scale_opt: Option<Spectrum>,
) {
let mut use_scale: bool = false;
let mut sc: Spectrum = Spectrum::default();
if let Some(scale) = scale_opt {
use_scale = true;
sc = scale;
}
if let Some(ref bump) = self.bump_map {
Material::bump(bump, si);
}
let eta: Float = 1.5;
let r: Spectrum = self
.reflect
.evaluate(si)
.clamp(0.0 as Float, std::f32::INFINITY as Float);
let t: Spectrum = self
.transmit
.evaluate(si)
.clamp(0.0 as Float, std::f32::INFINITY as Float);
if r.is_black() && t.is_black() {
si.bsdf = Some(Bsdf::new(si, eta));
return;
}
let kd: Spectrum = self
.kd
.evaluate(si)
.clamp(0.0 as Float, std::f32::INFINITY as Float);
let ks: Spectrum = self
.ks
.evaluate(si)
.clamp(0.0 as Float, std::f32::INFINITY as Float);
let mut rough: Float = self.roughness.evaluate(si);
si.bsdf = Some(Bsdf::new(si, eta));
if let Some(bsdf) = &mut si.bsdf {
if !kd.is_black() {
if !r.is_black() {
if use_scale {
bsdf.add(Bxdf::LambertianRefl(LambertianReflection::new(
r * kd,
Some(sc),
)));
} else {
bsdf.add(Bxdf::LambertianRefl(LambertianReflection::new(
r * kd,
None,
)));
}
}
if !t.is_black() {
if use_scale {
bsdf.add(Bxdf::LambertianTrans(LambertianTransmission::new(
t * kd,
Some(sc),
)));
} else {
bsdf.add(Bxdf::LambertianTrans(LambertianTransmission::new(
t * kd,
None,
)));
}
}
}
if !ks.is_black() && (!r.is_black() || !t.is_black()) {
if self.remap_roughness {
rough = TrowbridgeReitzDistribution::roughness_to_alpha(rough);
}
let distrib = MicrofacetDistribution::TrowbridgeReitz(
TrowbridgeReitzDistribution::new(rough, rough, true),
);
if !r.is_black() {
let fresnel = Fresnel::Dielectric(FresnelDielectric {
eta_i: 1.0 as Float,
eta_t: eta,
});
if use_scale {
bsdf.add(Bxdf::MicrofacetRefl(MicrofacetReflection::new(
r * ks,
distrib,
fresnel,
Some(sc),
)));
} else {
bsdf.add(Bxdf::MicrofacetRefl(MicrofacetReflection::new(
r * ks,
distrib,
fresnel,
None,
)));
}
}
let distrib = MicrofacetDistribution::TrowbridgeReitz(
TrowbridgeReitzDistribution::new(rough, rough, true),
);
if !t.is_black() {
if use_scale {
bsdf.add(Bxdf::MicrofacetTrans(MicrofacetTransmission::new(
t * ks,
distrib,
1.0,
eta,
mode,
Some(sc),
)));
} else {
bsdf.add(Bxdf::MicrofacetTrans(MicrofacetTransmission::new(
t * ks,
distrib,
1.0,
eta,
mode,
None,
)));
}
}
}
}
}
}
