Changes

gen_face.py

@@ -0,0 +1,118 @@
+#!/usr/bin/env python3
+"""
+gen_face.py  –  Run ONCE to generate assets/face_wire.png
+─────────────────────────────────────────────────────────
+Uses matplotlib's 3-D surface renderer to produce a wireframe face image
+that display.py loads.  Run it once; the PNG is then part of your project.
+
+    python gen_face.py
+
+Dependencies (dev machine only – NOT needed on the target device):
+    sudo apt install python3-matplotlib   # or: pip install matplotlib
+"""
+
+import os
+import math
+import argparse
+import numpy as np
+import matplotlib
+matplotlib.use('Agg')                       # off-screen — no display needed
+import matplotlib.pyplot as plt
+from mpl_toolkits.mplot3d import Axes3D    # noqa: F401
+
+# ── Face width profile ────────────────────────────────────────────────────────
+# (normalised_height, width_fraction)   0 = crown, 1 = chin
+# Widest point is at the cheekbones (~t=0.37), not the crown.
+# Crown and forehead are slightly narrower; jaw/chin taper below cheeks.
+_PROFILE = [
+    (0.00, 0.82),   # crown
+    (0.10, 0.88),   # upper skull
+    (0.22, 0.94),   # temples / forehead
+    (0.37, 1.00),   # cheekbones — widest
+    (0.50, 0.96),   # nose level
+    (0.62, 0.84),   # mouth level
+    (0.73, 0.68),   # jaw angle
+    (0.83, 0.50),   # lower jaw
+    (0.92, 0.30),   # chin
+    (1.00, 0.08),   # chin tip
+]
+
+
+def _face_r(v: float) -> float:
+    """Radial width at normalised height v ∈ [0, 1]."""
+    for i in range(len(_PROFILE) - 1):
+        t0, w0 = _PROFILE[i]
+        t1, w1 = _PROFILE[i + 1]
+        if t0 <= v <= t1:
+            return w0 + (v - t0) / (t1 - t0) * (w1 - w0)
+    return 0.0
+
+
+def face_surface(nu: int = 22, nv: int = 28):
+    """
+    Build the face mesh arrays.
+    Axis convention chosen to match matplotlib's default camera behaviour:
+      X  = left / right
+      Y  = depth  (positive = toward viewer / front of face)
+      Z  = up / down  (+1 = crown, −1 = chin)
+    To view from the front: view_init(elev, azim=90)  ← camera is at +Y
+    """
+    u_vals = np.linspace(-math.pi / 2, math.pi / 2, nu)   # front hemisphere
+    v_vals = np.linspace(0.0, 1.0, nv)                     # crown → chin
+
+    X = np.zeros((nv, nu))
+    Y = np.zeros((nv, nu))
+    Z = np.zeros((nv, nu))
+
+    for j, v in enumerate(v_vals):
+        r = _face_r(v)
+        z = math.cos(math.pi * v)   # +1 at crown, −1 at chin
+        for i, u in enumerate(u_vals):
+            X[j, i] = r * math.sin(u)    # left/right
+            Y[j, i] = r * math.cos(u)    # depth (front = max)
+            Z[j, i] = z                   # height
+
+    return X, Y, Z
+
+
+def generate(out_path: str = 'assets/face_wire.png',
+             img_w: int = 400, img_h: int = 500,
+             line_col: str = '#606060') -> None:
+    dpi = 100
+    fig = plt.figure(figsize=(img_w / dpi, img_h / dpi), facecolor='black')
+    ax  = fig.add_subplot(111, projection='3d', facecolor='black')
+
+    X, Y, Z = face_surface(nu=18, nv=22)
+    ax.plot_wireframe(X, Y, Z,
+                      color=line_col,
+                      linewidth=0.85,
+                      rstride=1, cstride=1)
+
+    # azim=90  →  camera at +Y, looking toward −Y (directly at face)
+    # elev=-8  →  camera slightly below horizontal = view from below,
+    #             shows chin/jaw, hides flat top of mesh — matches reference
+    ax.view_init(elev=-8, azim=90)
+
+    ax.set_axis_off()
+    # [x_width, y_depth, z_height]
+    # Key: y_depth very small → face is flat/mask-like, not a globe
+    ax.set_box_aspect([1.0, 0.28, 1.22])
+
+    plt.subplots_adjust(left=0, right=1, top=1, bottom=0)
+
+    os.makedirs(os.path.dirname(out_path) if os.path.dirname(out_path) else '.',
+                exist_ok=True)
+    fig.savefig(out_path, dpi=dpi, facecolor='black',
+                bbox_inches='tight', pad_inches=0.02)
+    plt.close(fig)
+    print(f'Saved  {out_path}  ({img_w}×{img_h} px)')
+
+
+if __name__ == '__main__':
+    ap = argparse.ArgumentParser()
+    ap.add_argument('--out',    default='assets/face_wire.png')
+    ap.add_argument('--width',  type=int, default=400)
+    ap.add_argument('--height', type=int, default=500)
+    ap.add_argument('--color',  default='#606060')
+    args = ap.parse_args()
+    generate(args.out, args.width, args.height, args.color)