oxihuman-mesh 0.2.1

Mesh processing, topology, and geometry algorithms for OxiHuman
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
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156

#![allow(dead_code)]
// Copyright (C) 2026 COOLJAPAN OU (Team KitaSan)
// SPDX-License-Identifier: Apache-2.0

//! Quad-dominant remeshing stub.

#[allow(dead_code)]
pub struct QuadRemeshResult {
    pub verts: Vec<[f32; 3]>,
    pub quads: Vec<[u32; 4]>,
    pub tris: Vec<[u32; 3]>,
}

#[allow(dead_code)]
pub fn remesh_to_quads(
    verts: &[[f32; 3]],
    tris: &[[u32; 3]],
    _target_edge_len: f32,
) -> QuadRemeshResult {
    let quads = pair_triangles_to_quads(tris);
    let used = quads.len() * 2;
    let remaining: Vec<[u32; 3]> = if used < tris.len() {
        tris[used..].to_vec()
    } else {
        Vec::new()
    };
    QuadRemeshResult {
        verts: verts.to_vec(),
        quads,
        tris: remaining,
    }
}

#[allow(dead_code)]
pub fn pair_triangles_to_quads(tris: &[[u32; 3]]) -> Vec<[u32; 4]> {
    let mut quads = Vec::new();
    let mut i = 0;
    while i + 1 < tris.len() {
        let t0 = tris[i];
        let t1 = tris[i + 1];
        quads.push([t0[0], t0[1], t1[2], t0[2]]);
        i += 2;
    }
    quads
}

#[allow(dead_code)]
pub fn quad_count(result: &QuadRemeshResult) -> usize {
    result.quads.len()
}

#[allow(dead_code)]
pub fn tri_count_remaining(result: &QuadRemeshResult) -> usize {
    result.tris.len()
}

#[cfg(test)]
mod tests {
    use super::*;

    fn sample_verts() -> Vec<[f32; 3]> {
        vec![
            [0.0, 0.0, 0.0],
            [1.0, 0.0, 0.0],
            [0.0, 1.0, 0.0],
            [1.0, 1.0, 0.0],
        ]
    }

    fn sample_tris() -> Vec<[u32; 3]> {
        vec![[0, 1, 2], [1, 3, 2]]
    }

    #[test]
    fn pair_two_tris_to_one_quad() {
        let tris = sample_tris();
        let quads = pair_triangles_to_quads(&tris);
        assert_eq!(quads.len(), 1);
    }

    #[test]
    fn pair_single_tri_yields_no_quads() {
        let tris = vec![[0u32, 1, 2]];
        let quads = pair_triangles_to_quads(&tris);
        assert!(quads.is_empty());
    }

    #[test]
    fn remesh_returns_correct_vert_count() {
        let verts = sample_verts();
        let tris = sample_tris();
        let result = remesh_to_quads(&verts, &tris, 0.5);
        assert_eq!(result.verts.len(), 4);
    }

    #[test]
    fn quad_count_matches() {
        let verts = sample_verts();
        let tris = sample_tris();
        let result = remesh_to_quads(&verts, &tris, 0.5);
        assert_eq!(quad_count(&result), 1);
    }

    #[test]
    fn tri_count_remaining_is_zero_for_even_tris() {
        let verts = sample_verts();
        let tris = sample_tris();
        let result = remesh_to_quads(&verts, &tris, 0.5);
        assert_eq!(tri_count_remaining(&result), 0);
    }

    #[test]
    fn odd_tri_count_leaves_one_remaining() {
        let verts = vec![
            [0.0f32, 0.0, 0.0],
            [1.0, 0.0, 0.0],
            [0.0, 1.0, 0.0],
            [1.0, 1.0, 0.0],
            [0.5, 2.0, 0.0],
        ];
        let tris = vec![[0u32, 1, 2], [1, 3, 2], [2, 3, 4]];
        let result = remesh_to_quads(&verts, &tris, 0.5);
        assert_eq!(tri_count_remaining(&result), 1);
    }

    #[test]
    fn empty_tris_gives_empty_result() {
        let verts = sample_verts();
        let result = remesh_to_quads(&verts, &[], 0.5);
        assert!(result.quads.is_empty());
        assert!(result.tris.is_empty());
    }

    #[test]
    fn quad_indices_come_from_source_tris() {
        let tris = vec![[0u32, 1, 2], [1, 3, 2]];
        let quads = pair_triangles_to_quads(&tris);
        assert_eq!(quads[0][0], 0);
        assert_eq!(quads[0][1], 1);
    }

    #[test]
    fn four_tris_gives_two_quads() {
        let tris = vec![[0u32, 1, 2], [1, 3, 2], [0, 2, 4], [2, 5, 4]];
        let quads = pair_triangles_to_quads(&tris);
        assert_eq!(quads.len(), 2);
    }

    #[test]
    fn remesh_large_edge_len_still_works() {
        let verts = sample_verts();
        let tris = sample_tris();
        let result = remesh_to_quads(&verts, &tris, 100.0);
        assert_eq!(result.verts.len(), verts.len());
    }
}