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Complete triangle mesh code (and more refactoring)

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This commit is contained in:
bijan2005 2020-12-07 12:04:44 -05:00
parent cddec468de
commit 4596c117df
5 changed files with 102 additions and 23 deletions
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2
README.md
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@ -24,7 +24,7 @@ This list may be changed or extended in the future.
- [x] Triangle normal generation
- [x] Color mapping on triangles
- [x] Triangle mesh struct
- [ ] Triangle mesh intersection test
- [x] Triangle mesh intersection test
- [ ] Bounding boxes
- [ ] Direct lighting
- [ ] Point light sources

7
src/main.rs
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@ -52,13 +52,10 @@ fn render(camera: &Camera, scene: &Scene, filename: &str) -> std::io::Result<()>
fn main() -> std::io::Result<()> {
let camera = Camera::new(Point3::new(0.0,1.0,0.0), Vector3::new(0.0,0.0,1.0), 1.0, 16.0 / 9.0, 2.0, 720);
let camera = Camera::new(Point3::new(0.0,0.0,0.0), Vector3::new(0.0,0.0,1.0), 1.0, 16.0 / 9.0, 2.0, 480);
let scene = vec![
Object::new(Plane::new(Point3::new(0.0, 0.0, -1.0), Vector3::x(), Vector3::z(),
|x, y| Color::gray(y / 30.0)
)),
Object::new(Sphere::new(0.0, 1.0, 4.0, 1.0, |x, y| Color::new(0.0, x, y)))
Object::new(TriangleMesh::singleton(Point3::new(-1.0, -1.0, 3.0), Point3::new(0.0, 1.0, 3.0), Point3::new(1.0, -1.0, 3.0), |t, u, v| Color::new(t, u, v)))
];
render(&camera, &scene, "out.ppm")

1
src/object/plane.rs
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@ -17,6 +17,7 @@ pub struct Plane {
// Input coordinates are defined in terms of the axes above.
}
#[allow(dead_code)]
impl Plane {
// Creates a new plane.
pub fn new<F: 'static>(center: Point3<f32>, x_axis: Vector3<f32>, y_axis: Vector3<f32>, texture: F) -> Self

1
src/object/sphere.rs
View file

@ -16,6 +16,7 @@ pub struct Sphere {
// Uses spherical coordinates (normalized from 0-1) as input.
}
#[allow(dead_code)]
impl Sphere {
// Creates a new sphere.
pub fn new<F: 'static>(x: f32, y: f32, z: f32, radius: f32, texture: F) -> Self

114
src/object/triangle.rs
View file

@ -1,5 +1,7 @@
extern crate nalgebra as na;
use std::cmp::Ordering;
use na::*;
use na::geometry::Point3;
@ -11,6 +13,7 @@ pub struct Triangle {
pub v2: usize,
pub v3: usize,
normal: Unit<Vector3<f32>>, // Precalculated normal vector.
area: f32, // Precalculated area for barycentric calculations.
texture: Box<dyn Fn(f32, f32, f32) -> Color> // Texture map.
@ -18,7 +21,7 @@ pub struct Triangle {
}
pub struct TriangleMesh {
pub points: Vec<Point3<f32>>,
pub vertices: Vec<Point3<f32>>,
pub tris: Vec<Triangle>
}
@ -47,7 +50,7 @@ impl Triangle {
(t, u, v)
}
fn intersect(&self, vertices: &Vec<Point3<f32>>, ray: Ray) -> Option<f32> {
fn intersect_(&self, vertices: &Vec<Point3<f32>>, ray: Ray) -> Option<(f32, f32, f32)> {
let vect2_1 = self.vertex2(vertices) - self.vertex1(vertices);
let vect3_1 = self.vertex3(vertices) - self.vertex1(vertices);
@ -66,53 +69,51 @@ impl Triangle {
if v < 0.0 || (u + v) > 1.0 { return None; }
let t = vect3_1.dot(&q_vect) / det;
let t = 1.0 - u - v;
// Convert from barycentric coordinates
Some(distance(&ray.origin, &self.from_bary(vertices, t, u, v)))
Some((t, u, v))
}
fn normal(&self, vertices: &Vec<Point3<f32>>, _point: Point3<f32>) -> Unit<Vector3<f32>> {
Unit::new_normalize((self.vertex2(vertices) - self.vertex1(vertices)).cross(&(self.vertex3(vertices) - self.vertex1(vertices))))
fn intersect(&self, vertices: &Vec<Point3<f32>>, ray: Ray) -> Option<f32> {
self.intersect_(vertices, ray).map(|(t, u, v)| distance(&ray.origin, &self.from_bary(vertices, t, u, v)))
}
fn getcolor(&self, vertices: &Vec<Point3<f32>>, point: Point3<f32>) -> Color {
// Converting back and forth between barycentric coordinates
// like this is terrible, but it's necessary for this object to
// match the interface the other objects use.
let (t, u, v) = self.to_bary(vertices, point);
(*self.texture)(t, u, v)
}
}
#[allow(dead_code)]
impl TriangleMesh {
pub fn new(points: Vec<Point3<f32>>, tris: Vec<(usize, usize, usize, Box<dyn Fn(f32, f32, f32) -> Color>)>) -> Self {
pub fn new(vertices: Vec<Point3<f32>>, tris: Vec<(usize, usize, usize, Box<dyn Fn(f32, f32, f32) -> Color>)>) -> Self {
let triangles = tris.into_iter()
.map(|(v1, v2, v3, f)| Triangle {
v1: v1,
v2: v2,
v3: v3,
area: tri_area(&points[v1], &points[v2], &points[v3]),
normal: Unit::new_normalize((&vertices[v2] - &vertices[v1]).cross(&(&vertices[v3] - &vertices[v1]))),
area: tri_area(&vertices[v1], &vertices[v2], &vertices[v3]),
texture: f
}).collect();
TriangleMesh {
points: points,
vertices: vertices,
tris: triangles
}
}
pub fn new_solid(points: Vec<Point3<f32>>, tris: Vec<(usize, usize, usize)>, color: Color) -> Self {
pub fn new_solid(vertices: Vec<Point3<f32>>, tris: Vec<(usize, usize, usize)>, color: Color) -> Self {
let triangles = tris.into_iter()
.map(|(v1, v2, v3)| Triangle {
v1: v1,
v2: v2,
v3: v3,
area: tri_area(&points[v1], &points[v2], &points[v3]),
normal: Unit::new_normalize((&vertices[v2] - &vertices[v1]).cross(&(&vertices[v3] - &vertices[v1]))),
area: tri_area(&vertices[v1], &vertices[v2], &vertices[v3]),
texture: Box::new(move |_, _, _| color)
}).collect();
TriangleMesh {
points: points,
vertices: vertices,
tris: triangles
}
}
@ -120,3 +121,82 @@ impl TriangleMesh {
pub fn singleton<F: 'static>(vertex1: Point3<f32>, vertex2: Point3<f32>, vertex3: Point3<f32>, texture: F) -> Self
where F: Fn(f32, f32, f32) -> Color
{ TriangleMesh::new(vec![vertex1, vertex2, vertex3], vec![(0, 1, 2, Box::new(texture))]) }
pub fn singleton_solid(vertex1: Point3<f32>, vertex2: Point3<f32>, vertex3: Point3<f32>, color: Color) -> Self
{ TriangleMesh::singleton(vertex1, vertex2, vertex3, move |_, _, _| color) }
fn closest_tri(&self, point: Point3<f32>) -> &Triangle {
self.tris.iter()
.map(move |tri| {
let rel_pos = point - tri.vertex1(&self.vertices);
let proj_point3 = rel_pos - (*tri.normal * tri.normal.dot(&rel_pos));
let (t, u, v) = tri.to_bary(&self.vertices, Point3::from(proj_point3));
let t = clamp(t, 0.0, 1.0);
let u = clamp(u, 0.0, 1.0);
let v = clamp(v, 0.0, 1.0);
let point_new = tri.from_bary(&self.vertices, t, u, v);
(tri, distance(&point, &point_new))
})
.min_by(|a, b| a.1.partial_cmp(&b.1).unwrap_or(Ordering::Equal))
.unwrap().0
}
}
impl Surface for TriangleMesh {
fn intersect(&self, ray: Ray) -> Option<f32> {
self.tris.iter()
.filter_map(|tri| tri.intersect(&self.vertices, ray))
.min_by(|a, b| a.partial_cmp(&b).unwrap_or(Ordering::Equal))
}
fn normal(&self, point: Point3<f32>) -> Unit<Vector3<f32>> {
self.closest_tri(point).normal
}
fn getcolor(&self, point: Point3<f32>) -> Color {
self.closest_tri(point).getcolor(&self.vertices, point)
}
}
#[cfg(test)]
mod tests {
use super::*;
fn roundcolor(color: Color) -> Color {
Color::new((color.red * 100.0).round() / 100.0, (color.green * 100.0).round() / 100.0, (color.blue * 100.0).round() / 100.0)
}
#[test]
fn triangle_intersect() {
let triangle = TriangleMesh::singleton_solid(Point3::new(0.0, 0.0, 0.0), Point3::new(1.0, 1.0, 0.0), Point3::new(0.0, 0.0, 1.0), Color::black());
let ray = Ray::new(Point3::new(0.5, 5.0, 0.3), Vector3::new(0.0, -1.0, 0.0));
let (t, u, v) = triangle.tris[0].intersect_(&triangle.vertices, ray).unwrap();
println!("{},{},{}", t, u, v);
assert!(t >= 0.0 && t <= 1.0);
assert!(u >= 0.0 && u <= 1.0);
assert!(v >= 0.0 && v <= 1.0);
}
#[test]
fn triangle_getcolor() {
let triangle = TriangleMesh::singleton(Point3::new(0.0, 0.0, 0.0), Point3::new(1.0, 1.0, 0.0), Point3::new(0.0, 0.0, 1.0), |t, u, v| Color::new(t, u, v));
let t = 0.4;
let u = 0.1;
let v = 1.0 - t - u;
let point = triangle.tris[0].from_bary(&triangle.vertices, t, u, v);
assert_eq!(roundcolor(triangle.getcolor(point)), roundcolor(Color::new(t, u, v)));
}
}