oxihuman-morph 0.1.2

Parametric morphology engine for human body generation — targets, blendshapes, FACS
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

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

//! Infant/baby body proportion morph.

/// Configuration for the infant morph.
#[derive(Debug, Clone)]
pub struct InfantMorphConfig {
    /// Head-to-body ratio multiplier (infants ~1/4 body height).
    pub head_ratio: f32,
    /// Limb shortening factor relative to adult.
    pub limb_scale: f32,
    /// Belly roundness.
    pub belly_roundness: f32,
}

impl Default for InfantMorphConfig {
    fn default() -> Self {
        InfantMorphConfig {
            head_ratio: 1.0,
            limb_scale: 0.45,
            belly_roundness: 0.8,
        }
    }
}

/// State for the infant body morph.
#[derive(Debug, Clone)]
pub struct InfantMorph {
    /// Age in months (0–24).
    pub age_months: f32,
    pub config: InfantMorphConfig,
    pub enabled: bool,
}

/// Create a new infant morph at birth (0 months).
pub fn new_infant_morph() -> InfantMorph {
    InfantMorph {
        age_months: 0.0,
        config: InfantMorphConfig::default(),
        enabled: true,
    }
}

/// Set age in months (clamped to 0–24).
pub fn im_set_age(m: &mut InfantMorph, months: f32) {
    m.age_months = months.clamp(0.0, 24.0);
}

/// Normalised morphing weight (0 = newborn, 1 = 24 months).
pub fn im_weight(m: &InfantMorph) -> f32 {
    m.age_months / 24.0
}

/// Head scale factor (infants have proportionally larger heads).
pub fn im_head_scale(m: &InfantMorph) -> f32 {
    let t = im_weight(m);
    m.config.head_ratio * (1.0 - 0.3 * t)
}

/// Limb length scale relative to adult norm.
pub fn im_limb_scale(m: &InfantMorph) -> f32 {
    let t = im_weight(m);
    m.config.limb_scale + 0.1 * t
}

/// Serialise to JSON string.
pub fn im_to_json(m: &InfantMorph) -> String {
    format!(
        r#"{{"age_months":{:.1},"enabled":{},"head_scale":{:.3}}}"#,
        m.age_months,
        m.enabled,
        im_head_scale(m)
    )
}

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

    #[test]
    fn default_is_newborn() {
        let m = new_infant_morph();
        assert!((m.age_months - 0.0).abs() < 1e-6 /* newborn age */);
    }

    #[test]
    fn set_age_clamps_upper() {
        let mut m = new_infant_morph();
        im_set_age(&mut m, 100.0);
        assert!((m.age_months - 24.0).abs() < 1e-6 /* clamped */);
    }

    #[test]
    fn weight_at_24_months_is_one() {
        let mut m = new_infant_morph();
        im_set_age(&mut m, 24.0);
        assert!((im_weight(&m) - 1.0).abs() < 1e-6 /* full weight */);
    }

    #[test]
    fn head_scale_decreases_with_age() {
        let mut m = new_infant_morph();
        im_set_age(&mut m, 0.0);
        let h0 = im_head_scale(&m);
        im_set_age(&mut m, 24.0);
        let h24 = im_head_scale(&m);
        assert!(h0 > h24 /* head relatively larger at birth */);
    }

    #[test]
    fn limb_scale_increases_with_age() {
        let mut m = new_infant_morph();
        im_set_age(&mut m, 0.0);
        let l0 = im_limb_scale(&m);
        im_set_age(&mut m, 24.0);
        let l24 = im_limb_scale(&m);
        assert!(l24 > l0 /* limbs grow with age */);
    }

    #[test]
    fn to_json_has_age() {
        let mut m = new_infant_morph();
        im_set_age(&mut m, 6.0);
        assert!(im_to_json(&m).contains("6.0") /* json has age */);
    }

    #[test]
    fn enabled_toggle() {
        let mut m = new_infant_morph();
        m.enabled = false;
        assert!(!m.enabled /* disabled */);
    }

    #[test]
    fn belly_roundness_in_config() {
        let m = new_infant_morph();
        assert!(m.config.belly_roundness > 0.0 /* non-zero belly roundness */);
    }
}