enginerenderer 0.0.1

A zero-dependency offline rendering engine in pure Rust — CPU path tracing, BVH acceleration, 16-band spectral rendering, PBR materials, animation & video export.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108

use crate::core::engine::rendering::raytracing::{Material, Triangle, Vec3};

#[derive(Debug, Clone, Copy)]
pub struct RingSpec {
    pub center: Vec3,
    pub inner_radius: f64,
    pub outer_radius: f64,
    pub axis_u: Vec3,
    pub axis_v: Vec3,
    pub segments: usize,
    pub material: Material,
}

pub fn append_box(triangles: &mut Vec<Triangle>, center: Vec3, half: Vec3, material: Material) {
    let p000 = center + Vec3::new(-half.x, -half.y, -half.z);
    let p001 = center + Vec3::new(-half.x, -half.y, half.z);
    let p010 = center + Vec3::new(-half.x, half.y, -half.z);
    let p011 = center + Vec3::new(-half.x, half.y, half.z);
    let p100 = center + Vec3::new(half.x, -half.y, -half.z);
    let p101 = center + Vec3::new(half.x, -half.y, half.z);
    let p110 = center + Vec3::new(half.x, half.y, -half.z);
    let p111 = center + Vec3::new(half.x, half.y, half.z);

    append_quad(triangles, p001, p101, p111, p011, material);
    append_quad(triangles, p100, p000, p010, p110, material);
    append_quad(triangles, p000, p001, p011, p010, material);
    append_quad(triangles, p101, p100, p110, p111, material);
    append_quad(triangles, p010, p011, p111, p110, material);
    append_quad(triangles, p000, p100, p101, p001, material);
}

pub fn append_quad(
    triangles: &mut Vec<Triangle>,
    a: Vec3,
    b: Vec3,
    c: Vec3,
    d: Vec3,
    material: Material,
) {
    triangles.push(Triangle::flat(a, b, c, material));
    triangles.push(Triangle::flat(a, c, d, material));
}

pub fn append_ring(triangles: &mut Vec<Triangle>, ring: RingSpec) {
    let u = ring.axis_u.normalize();
    let v = ring.axis_v.normalize();
    let segment_count = ring.segments.max(12);

    for segment in 0..segment_count {
        let start = std::f64::consts::TAU * segment as f64 / segment_count as f64;
        let end = std::f64::consts::TAU * (segment + 1) as f64 / segment_count as f64;
        let dir_start = u * start.cos() + v * start.sin();
        let dir_end = u * end.cos() + v * end.sin();

        let inner_start = ring.center + dir_start * ring.inner_radius;
        let outer_start = ring.center + dir_start * ring.outer_radius;
        let inner_end = ring.center + dir_end * ring.inner_radius;
        let outer_end = ring.center + dir_end * ring.outer_radius;
        append_quad(
            triangles,
            inner_start,
            outer_start,
            outer_end,
            inner_end,
            ring.material,
        );
    }
}

pub fn append_gabled_roof(
    triangles: &mut Vec<Triangle>,
    center: Vec3,
    half_width: f64,
    half_depth: f64,
    roof_height: f64,
    material: Material,
) {
    let left_front = center + Vec3::new(-half_width, 0.0, half_depth);
    let right_front = center + Vec3::new(half_width, 0.0, half_depth);
    let left_back = center + Vec3::new(-half_width, 0.0, -half_depth);
    let right_back = center + Vec3::new(half_width, 0.0, -half_depth);
    let ridge_front = center + Vec3::new(0.0, roof_height, half_depth);
    let ridge_back = center + Vec3::new(0.0, roof_height, -half_depth);

    append_quad(
        triangles,
        left_front,
        left_back,
        ridge_back,
        ridge_front,
        material,
    );
    append_quad(
        triangles,
        right_front,
        ridge_front,
        ridge_back,
        right_back,
        material,
    );
    triangles.push(Triangle::flat(
        left_front,
        right_front,
        ridge_front,
        material,
    ));
    triangles.push(Triangle::flat(left_back, ridge_back, right_back, material));
}