pbrt/src/core/interaction.rs

319 lines
8 KiB
Rust

use crate::core::bxdf::BSDF;
use crate::core::material::MaterialTrait;
use crate::core::medium::{Medium, MediumInterface};
use crate::core::pbrt::Float;
use crate::geometry::{Normal3f, Point2f, Point3f, Point3fi, Ray, Vector3f, VectorLike};
use crate::lights::Light;
use crate::shapes::ShapeTrait;
use std::any::Any;
use std::sync::Arc;
#[derive(Default, Clone, Debug)]
pub struct InteractionData {
pub pi: Point3fi,
pub n: Normal3f,
pub time: Float,
pub wo: Vector3f,
pub medium_interface: Option<Arc<MediumInterface>>,
pub medium: Option<Arc<Medium>>,
}
pub trait Interaction: Send + Sync {
fn get_common(&self) -> &InteractionData;
fn get_common_mut(&mut self) -> &mut InteractionData;
fn as_any(&self) -> &dyn Any;
fn p(&self) -> Point3f {
self.get_common().pi.into()
}
fn pi(&self) -> Point3fi {
self.get_common().pi
}
fn time(&self) -> Float {
self.get_common().time
}
fn wo(&self) -> Vector3f {
self.get_common().wo
}
fn n(&self) -> Normal3f {
self.get_common().n
}
fn is_surface_interaction(&self) -> bool {
self.as_any().is::<SurfaceInteraction>()
}
fn is_medium_interaction(&self) -> bool {
self.as_any().is::<MediumInteraction>()
}
fn get_medium(&self, w: Vector3f) -> Option<Arc<Medium>>;
fn spawn_ray(&self, d: Vector3f) -> Ray;
fn spawn_ray_to_point(&self, p2: Point3f) -> Ray {
let origin = self.p();
let direction = p2 - origin;
Ray {
o: origin,
d: direction,
time: self.time(),
medium: self.get_medium(direction),
differential: None,
}
}
fn spawn_ray_to_interaction(&self, other: &dyn Interaction) -> Ray {
self.spawn_ray_to_point(other.p())
}
fn offset_ray_vector(&self, w: Vector3f) -> Point3f {
Ray::offset_origin(&self.pi(), &self.n(), &w)
}
fn offset_ray_point(&self, pt: Point3f) -> Point3f {
self.offset_ray_vector(pt - self.p())
}
}
#[derive(Default, Clone, Debug)]
pub struct ShadingGeometry {
pub n: Normal3f,
pub dpdu: Vector3f,
pub dpdv: Vector3f,
pub dndu: Normal3f,
pub dndv: Normal3f,
}
#[derive(Default, Debug, Clone)]
pub struct SurfaceInteraction {
pub common: InteractionData,
pub uv: Point2f,
pub dpdu: Vector3f,
pub dpdv: Vector3f,
pub dndu: Normal3f,
pub dndv: Normal3f,
pub shading: ShadingGeometry,
pub medium_interface: Option<Arc<MediumInterface>>,
pub face_index: usize,
pub area_light: Option<Arc<Light>>,
pub material: Option<Arc<dyn MaterialTrait>>,
pub dpdx: Vector3f,
pub dpdy: Vector3f,
pub dudx: Float,
pub dvdx: Float,
pub dudy: Float,
pub dvdy: Float,
pub shape: Option<Arc<dyn ShapeTrait>>,
pub bsdf: Option<BSDF>,
}
impl SurfaceInteraction {
pub fn set_intersection_properties(
&mut self,
mtl: Arc<dyn MaterialTrait>,
area: Arc<Light>,
prim_medium_interface: Option<Arc<MediumInterface>>,
ray_medium: Arc<Medium>,
) {
self.material = Some(mtl);
self.area_light = Some(area);
if prim_medium_interface.as_ref().map_or(false, |mi| mi.is_medium_transition()) {
self.common.medium_interface = prim_medium_interface;
} else {
self.common.medium = Some(ray_medium);
}
}
}
pub struct PhaseFunction;
pub struct MediumInteraction {
pub common: InteractionData,
pub medium: Arc<Medium>,
pub phase: PhaseFunction,
}
impl Interaction for SurfaceInteraction {
fn get_common(&self) -> &InteractionData {
&self.common
}
fn get_common_mut(&mut self) -> &mut InteractionData {
&mut self.common
}
fn as_any(&self) -> &dyn Any {
self
}
fn get_medium(&self, w: Vector3f) -> Option<Arc<Medium>> {
self.medium_interface.as_ref().and_then(|interface| {
if self.n().dot(w.into()) > 0.0 {
interface.outside.clone()
} else {
interface.inside.clone()
}
})
}
fn spawn_ray(&self, d: Vector3f) -> Ray {
let mut ray = Ray::spawn(&self.pi(), &self.n(), self.time(), d);
ray.medium = self.get_medium(d);
ray
}
fn spawn_ray_to_point(&self, p2: Point3f) -> Ray {
let mut ray = Ray::spawn_to_point(&self.pi(), &self.n(), self.time(), p2);
ray.medium = self.get_medium(ray.d);
ray
}
fn spawn_ray_to_interaction(&self, other: &dyn Interaction) -> Ray {
// Check if the other interaction is a surface to use the robust spawn method
if let Some(si_to) = other.as_any().downcast_ref::<SurfaceInteraction>() {
let mut ray = Ray::spawn_to_interaction(
&self.pi(),
&self.n(),
self.time(),
&si_to.pi(),
&si_to.n(),
);
ray.medium = self.get_medium(ray.d);
ray
} else {
// Fallback for non-surface interactions
self.spawn_ray_to_point(other.p())
}
}
}
impl SurfaceInteraction {
pub fn new(
pi: Point3fi,
uv: Point2f,
wo: Vector3f,
dpdu: Vector3f,
dpdv: Vector3f,
dndu: Normal3f,
dndv: Normal3f,
time: Float,
flip: bool,
) -> Self {
let mut n = Normal3f::from(dpdu.cross(dpdv).normalize());
let mut shading_n = n;
if flip {
n *= -1.0;
shading_n *= -1.0;
}
Self {
common: InteractionData { pi, n, time, wo, medium_interface: None, medium: None },
uv,
dpdu,
dpdv,
dndu,
dndv,
shading: ShadingGeometry {
n: shading_n,
dpdu,
dpdv,
dndu,
dndv,
},
medium_interface: None,
material: None,
face_index: 0,
area_light: None,
dpdx: Vector3f::zero(),
dpdy: Vector3f::zero(),
dudx: 0.0,
dudy: 0.0,
dvdx: 0.0,
dvdy: 0.0,
shape: None,
bsdf: None,
}
}
pub fn new_with_face(
pi: Point3fi,
uv: Point2f,
wo: Vector3f,
dpdu: Vector3f,
dpdv: Vector3f,
dndu: Normal3f,
dndv: Normal3f,
time: Float,
flip: bool,
face_index: usize,
) -> Self {
let mut si = Self::new(pi, uv, wo, dpdu, dpdv, dndu, dndv, time, flip);
si.face_index = face_index;
si
}
pub fn set_shading_geometry(
&mut self,
ns: Normal3f,
dpdus: Vector3f,
dpdvs: Vector3f,
dndus: Normal3f,
dndvs: Normal3f,
orientation: bool,
) {
self.shading.n = ns;
if orientation {
self.common.n = self.n().face_forward(self.shading.n.into());
}
self.shading.dpdu = dpdus;
self.shading.dpdv = dpdvs;
self.shading.dndu = dndus.into();
self.shading.dndv = dndvs.into();
}
pub fn new_simple(pi: Point3fi, n: Normal3f, uv: Point2f) -> Self {
let mut si = Self::default();
si.common = InteractionData {
pi,
n,
time: 0.,
wo: Vector3f::zero(),
medium_interface: None,
medium: None,
};
si.uv = uv;
si
}
}
impl Interaction for MediumInteraction {
fn get_common(&self) -> &InteractionData {
&self.common
}
fn get_common_mut(&mut self) -> &mut InteractionData {
&mut self.common
}
fn as_any(&self) -> &dyn Any {
self
}
fn get_medium(&self, _w: Vector3f) -> Option<Arc<Medium>> {
Some(self.medium.clone())
}
fn spawn_ray(&self, d: Vector3f) -> Ray {
Ray {
o: self.p(),
d,
time: self.time(),
medium: Some(self.medium.clone()),
differential: None,
}
}
}