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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, FresnelSpecular, MicrofacetReflection,
MicrofacetTransmission, SpecularReflection, SpecularTransmission,
};
use crate::core::texture::Texture;
pub struct GlassMaterial {
pub kr: Arc<dyn Texture<Spectrum> + Sync + Send>,
pub kt: Arc<dyn Texture<Spectrum> + Sync + Send>,
pub u_roughness: Arc<dyn Texture<Float> + Sync + Send>,
pub v_roughness: Arc<dyn Texture<Float> + Sync + Send>,
pub index: Arc<dyn Texture<Float> + Sync + Send>,
pub bump_map: Option<Arc<dyn Texture<Float> + Send + Sync>>,
pub remap_roughness: bool,
}
impl GlassMaterial {
pub fn new(
kr: Arc<dyn Texture<Spectrum> + Sync + Send>,
kt: Arc<dyn Texture<Spectrum> + Sync + Send>,
u_roughness: Arc<dyn Texture<Float> + Sync + Send>,
v_roughness: Arc<dyn Texture<Float> + Sync + Send>,
index: Arc<dyn Texture<Float> + Send + Sync>,
bump_map: Option<Arc<dyn Texture<Float> + Sync + Send>>,
remap_roughness: bool,
) -> Self {
GlassMaterial {
kr,
kt,
u_roughness,
v_roughness,
index,
bump_map,
remap_roughness,
}
}
pub fn create(mp: &mut TextureParams) -> Arc<Material> {
let kr = mp.get_spectrum_texture("Kr", Spectrum::new(1.0 as Float));
let kt = mp.get_spectrum_texture("Kt", Spectrum::new(1.0 as Float));
let roughu = mp.get_float_texture("uroughness", 0.0 as Float);
let roughv = mp.get_float_texture("vroughness", 0.0 as Float);
let bump_map = mp.get_float_texture_or_null("bumpmap");
let remap_roughness: bool = mp.find_bool("remaproughness", true);
let eta_option: Option<Arc<dyn Texture<Float> + Send + Sync>> =
mp.get_float_texture_or_null("eta");
if let Some(ref eta) = eta_option {
Arc::new(Material::Glass(Box::new(GlassMaterial::new(
kr,
kt,
roughu,
roughv,
eta.clone(),
bump_map,
remap_roughness,
))))
} else {
let eta: Arc<dyn Texture<Float> + Send + Sync> =
mp.get_float_texture("index", 1.5 as Float);
Arc::new(Material::Glass(Box::new(GlassMaterial::new(
kr,
kt,
roughu,
roughv,
eta,
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 mut urough: Float = self.u_roughness.evaluate(si);
let mut vrough: Float = self.v_roughness.evaluate(si);
let r: Spectrum = self
.kr
.evaluate(si)
.clamp(0.0 as Float, std::f32::INFINITY as Float);
let t: Spectrum = self
.kt
.evaluate(si)
.clamp(0.0 as Float, std::f32::INFINITY as Float);
let is_specular: bool = urough == 0.0 as Float && vrough == 0.0 as Float;
let eta: Float = self.index.evaluate(si);
si.bsdf = Some(Bsdf::new(si, eta));
if let Some(bsdf) = &mut si.bsdf {
if is_specular && allow_multiple_lobes {
if use_scale {
bsdf.add(Bxdf::FresnelSpec(FresnelSpecular::new(
r,
t,
1.0 as Float,
eta,
mode,
Some(sc),
)));
} else {
bsdf.add(Bxdf::FresnelSpec(FresnelSpecular::new(
r,
t,
1.0 as Float,
eta,
mode,
None,
)));
}
} else {
if self.remap_roughness {
urough = TrowbridgeReitzDistribution::roughness_to_alpha(urough);
vrough = TrowbridgeReitzDistribution::roughness_to_alpha(vrough);
}
if !r.is_black() {
let fresnel = Fresnel::Dielectric(FresnelDielectric {
eta_i: 1.0 as Float,
eta_t: eta,
});
if is_specular {
if use_scale {
bsdf.add(Bxdf::SpecRefl(SpecularReflection::new(
r,
fresnel,
Some(sc),
)));
} else {
bsdf.add(Bxdf::SpecRefl(SpecularReflection::new(r, fresnel, None)));
}
} else {
let distrib = MicrofacetDistribution::TrowbridgeReitz(
TrowbridgeReitzDistribution::new(urough, vrough, true),
);
if use_scale {
bsdf.add(Bxdf::MicrofacetRefl(MicrofacetReflection::new(
r,
distrib,
fresnel,
Some(sc),
)));
} else {
bsdf.add(Bxdf::MicrofacetRefl(MicrofacetReflection::new(
r, distrib, fresnel, None,
)));
}
}
}
if !t.is_black() {
if is_specular {
if use_scale {
bsdf.add(Bxdf::SpecTrans(SpecularTransmission::new(
t,
1.0,
eta,
mode,
Some(sc),
)));
} else {
bsdf.add(Bxdf::SpecTrans(SpecularTransmission::new(
t, 1.0, eta, mode, None,
)));
}
} else {
let distrib = MicrofacetDistribution::TrowbridgeReitz(
TrowbridgeReitzDistribution::new(urough, vrough, true),
);
if use_scale {
bsdf.add(Bxdf::MicrofacetTrans(MicrofacetTransmission::new(
t,
distrib,
1.0,
eta,
mode,
Some(sc),
)));
} else {
bsdf.add(Bxdf::MicrofacetTrans(MicrofacetTransmission::new(
t, distrib, 1.0, eta, mode, None,
)));
}
}
}
}
}
}
}
