Draw first real image

This commit is contained in:
hal8174 2024-09-29 20:25:20 +02:00
parent 62b9fdcb56
commit 50d3874467
16 changed files with 565 additions and 56 deletions

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use rand::Rng;
use ray_tracing_core::material::DefaultMaterial;
use ray_tracing_core::prelude::*;
use ray_tracing_core::scene::{Intersection, Scene};
pub struct BasicScene {
pub(crate) spheres: Vec<(Pos3, Float)>,
}
impl BasicScene {
pub fn new() -> Self {
Self {
spheres: vec![(Pos3::zero(), 1.0), (Pos3::new(0.0, 0.0, 2.5), 2.0)],
}
}
}
impl<R: Rng> Scene<R> for BasicScene {
fn intersect(&self, ray: Ray, min: Float, max: Float) -> Option<Intersection<'_, R>> {
let mut intersection: Option<Intersection<'_, R>> = None;
for &(c, r) in &self.spheres {
let offset = ray.start() - c;
let p = Dir3::dot(ray.dir(), offset);
let delta = p * p - (offset.length_squared() - r * r);
if delta >= 0.0 {
let d = -p - Float::sqrt(delta);
let int = Intersection::new(
d,
((ray.start() + d * ray.dir()) - c).normalize(),
&DefaultMaterial {},
);
if d >= min && d <= max {
if let Some(i) = intersection.as_ref() {
if i.t() > d {
intersection.replace(int);
}
} else {
intersection = Some(int)
}
}
}
}
intersection
}
}

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use rand::Rng;
use ray_tracing_core::material::DefaultMaterial;
use ray_tracing_core::prelude::*;
use ray_tracing_core::scene::{Intersection, Scene};
pub mod sphere;
pub mod basic_scene;
pub struct BasicScene {
spheres: Vec<(Pos3, Float)>,
}
impl BasicScene {
pub fn new() -> Self {
Self {
spheres: vec![(Pos3::zero(), 1.0), (Pos3::new(0.0, 0.0, 2.5), 2.0)],
}
}
}
impl<R: Rng> Scene<R> for BasicScene {
fn intersect(&self, ray: Ray, min: Float, max: Float) -> Option<Intersection<'_, R>> {
let mut intersection: Option<Intersection<'_, R>> = None;
for &(c, r) in &self.spheres {
let offset = ray.start() - c;
let p = Dir3::dot(ray.dir(), offset);
let delta = p * p - (offset.length_squared() - r * r);
if delta >= 0.0 {
let d = -p - Float::sqrt(delta);
let int = Intersection::new(
d,
((ray.start() + d * ray.dir()) - c).normalize(),
&DefaultMaterial {},
);
if d >= min && d <= max {
if let Some(i) = intersection.as_ref() {
if i.t() > d {
intersection.replace(int);
}
} else {
intersection = Some(int)
}
}
}
}
intersection
}
}
pub mod triangle_bvh;

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use rand::Rng;
use ray_tracing_core::{
prelude::*,
scene::{Intersection, Scene},
};
type Index = u32;
pub struct TriangleBVH<R: Rng> {
vertices: Vec<Pos3>,
triangles: Vec<Triangle>,
materials: Vec<Box<dyn Material<R>>>,
bvh: Vec<Node>,
}
#[derive(Debug, Clone, Copy)]
enum Node {
Inner {
left: Index,
left_aabb: AABB,
right: Index,
right_aabb: AABB,
},
Leaf {
start: Index,
count: Index,
},
}
#[derive(Debug, Clone, Copy)]
pub struct Triangle {
vertices: [Index; 3],
material: Index,
}
impl Triangle {
fn new(vertices: [Index; 3], material: Index) -> Self {
Triangle { vertices, material }
}
}
fn triangle_intersection(ray: Ray, v: [Pos3; 3]) -> Option<Float> {
let e1 = v[1] - v[0];
let e2 = v[2] - v[0];
let ray_cross_e2 = Dir3::cross(ray.dir(), e2);
let det = e1.dot(ray_cross_e2);
if det > -f32::EPSILON && det < f32::EPSILON {
return None; // This ray is parallel to this triangle.
}
let inv_det = 1.0 / det;
let s = ray.start() - v[0];
let u = inv_det * s.dot(ray_cross_e2);
if u < 0.0 || u > 1.0 {
return None;
}
let s_cross_e1 = s.cross(e1);
let v = inv_det * Dir3::dot(ray.dir(), s_cross_e1);
if v < 0.0 || u + v > 1.0 {
return None;
}
// At this stage we can compute t to find out where the intersection point is on the line.
let t = inv_det * e2.dot(s_cross_e1);
if t > Float::EPSILON {
// ray intersection
Some(t)
} else {
// This means that there is a line intersection but not a ray intersection.
None
}
}
fn triangle_normal(v: [Pos3; 3]) -> Dir3 {
let e1 = v[1] - v[0];
let e2 = v[2] - v[0];
Dir3::cross(e1, e2)
}
impl<R: Rng> TriangleBVH<R> {
fn new(
vertices: Vec<Pos3>,
triangles: Vec<Triangle>,
materials: Vec<Box<dyn Material<R>>>,
) -> Self {
Self {
vertices,
bvh: vec![Node::Leaf {
start: 0,
count: triangles.len() as Index,
}],
triangles,
materials,
}
}
fn get_vertices(&self, triangle: Index) -> [Pos3; 3] {
let t = self.triangles[triangle as usize];
[
self.vertices[t.vertices[0] as usize],
self.vertices[t.vertices[1] as usize],
self.vertices[t.vertices[2] as usize],
]
}
fn intersect_bvh(
&self,
node: Index,
ray: Ray,
min: Float,
max: Float,
) -> Option<(Index, Float)> {
match self.bvh[node as usize] {
Node::Inner {
left,
left_aabb,
right,
right_aabb,
} => todo!(),
Node::Leaf { start, count } => {
let mut intersection = None;
for i in start..(start + count) {
if let Some(t) = triangle_intersection(ray, self.get_vertices(i)) {
if min <= t && t <= max && !intersection.is_some_and(|(_, old_t)| t > old_t)
{
intersection.replace((i, t));
}
}
}
intersection
}
}
}
}
impl<R: Rng> Scene<R> for TriangleBVH<R> {
fn intersect(
&self,
ray: Ray,
min: Float,
max: Float,
) -> Option<ray_tracing_core::scene::Intersection<'_, R>> {
let (i, t) = self.intersect_bvh(0, ray, min, max)?;
let triangle = self.triangles[i as usize];
let material = self.materials[triangle.material as usize].as_ref();
let n = triangle_normal(self.get_vertices(i)).normalize();
Some(Intersection::new(t, n, material))
}
}
pub mod examples {
use super::{Triangle, TriangleBVH};
use rand::Rng;
use ray_tracing_core::material::{AreaLight, DiffuseMaterial};
use ray_tracing_core::prelude::*;
pub fn cornel<R: Rng>() -> TriangleBVH<R> {
let side_length = 1.5;
let light_size = 0.5;
let light_offset = 0.01;
TriangleBVH::new(
vec![
Pos3::new(side_length, side_length, side_length),
Pos3::new(side_length, side_length, -side_length),
Pos3::new(side_length, -side_length, side_length),
Pos3::new(side_length, -side_length, -side_length),
Pos3::new(-side_length, side_length, side_length),
Pos3::new(-side_length, side_length, -side_length),
Pos3::new(-side_length, -side_length, side_length),
Pos3::new(-side_length, -side_length, -side_length),
Pos3::new(light_size, side_length - light_offset, light_size),
Pos3::new(light_size, side_length - light_offset, -light_size),
Pos3::new(-light_size, side_length - light_offset, light_size),
Pos3::new(-light_size, side_length - light_offset, -light_size),
],
vec![
Triangle::new([0, 1, 2], 0),
Triangle::new([1, 3, 2], 0),
Triangle::new([0, 4, 1], 0),
Triangle::new([1, 4, 5], 0),
Triangle::new([2, 3, 6], 0),
Triangle::new([3, 7, 6], 0),
Triangle::new([0, 2, 4], 1),
Triangle::new([6, 4, 2], 1),
Triangle::new([1, 5, 3], 2),
Triangle::new([7, 3, 5], 2),
Triangle::new([8, 10, 9], 3),
Triangle::new([11, 9, 10], 3),
],
vec![
Box::new(DiffuseMaterial::new(Color::new(0.8, 0.8, 0.8))),
Box::new(DiffuseMaterial::new(Color::new(0.9, 0.0, 0.0))),
Box::new(DiffuseMaterial::new(Color::new(0.0, 0.9, 0.0))),
Box::new(AreaLight::new(Color::new(5.0, 5.0, 5.0))),
],
)
}
}