"""Crater meadow (first biome): tileable ground textures for the 3D bridge. Painted after docs/inspiration/fonds/crater_meadow_0.png: dark, desaturated olive grass in short strokes, bare brown soil with pebbles and litter, and a low-frequency mask that decides where the soil shows through. Every texture tiles: noise is built in the frequency domain (periodic by construction) and strokes wrap around the edges. Run headless from big-egg-3d/: blender --background --factory-startup --python tools/blender/crater_meadow_textures.py """ import bpy, os import numpy as np HERE = os.path.dirname(os.path.abspath(__file__)) PROJECT = os.path.dirname(os.path.dirname(HERE)) OUT = os.path.join(PROJECT, "assets", "textures", "biomes", "crater_meadow") SIZE = 1024 rng = np.random.default_rng(20260929) def hex_rgb(h): h = h.lstrip("#") return np.array([int(h[i:i + 2], 16) / 255.0 for i in (0, 2, 4)]) def periodic_noise(size, beta, seed): """Tileable fractal noise in [0, 1]; larger beta = smoother.""" r = np.random.default_rng(seed) white = r.standard_normal((size, size)) fx = np.fft.fftfreq(size)[:, None] fy = np.fft.fftfreq(size)[None, :] f = np.sqrt(fx * fx + fy * fy) f[0, 0] = 1.0 spectrum = np.fft.fft2(white) / f ** beta spectrum[0, 0] = 0.0 n = np.real(np.fft.ifft2(spectrum)) n -= n.min() return n / n.max() def stamp_strokes(img, count, length, width, colors, jitter, seed, angle_bias=None, alpha=1.0): """Short wrapped strokes: grass blades seen from above.""" r = np.random.default_rng(seed) size = img.shape[0] x0 = r.uniform(0, size, count) y0 = r.uniform(0, size, count) ang = r.uniform(0, np.pi * 2, count) if angle_bias is None else r.normal(angle_bias, 0.6, count) ln = r.uniform(length[0], length[1], count) cidx = r.integers(0, len(colors), count) shade = r.uniform(1 - jitter, 1 + jitter, count) steps = int(length[1]) + 1 for s in range(steps): t = s / steps live = t * ln[:, None][:, 0] <= ln # Blades taper: full width at the root, one pixel at the tip. w = np.maximum(1, np.round(width * (1.0 - t))).astype(int) xs = x0 + np.cos(ang) * ln * t ys = y0 + np.sin(ang) * ln * t for dx in range(-(width // 2), width // 2 + 1): ok = live & (np.abs(dx) < w) xi = (np.round(xs[ok] + dx).astype(int)) % size yi = (np.round(ys[ok]).astype(int)) % size col = colors[cidx[ok]] * shade[ok, None] img[yi, xi] = img[yi, xi] * (1 - alpha) + col * alpha def stamp_blobs(img, count, radius, fill, rim, seed, highlight=None): """Pebbles: filled ellipses with a dark rim and a lit top edge.""" r = np.random.default_rng(seed) size = img.shape[0] for _ in range(count): cx, cy = r.uniform(0, size, 2) rx = r.uniform(*radius) ry = rx * r.uniform(0.6, 1.0) rot = r.uniform(0, np.pi) c = fill * r.uniform(0.8, 1.15) R = int(rx + 3) yy, xx = np.mgrid[-R:R + 1, -R:R + 1] u = (xx * np.cos(rot) + yy * np.sin(rot)) / rx v = (-xx * np.sin(rot) + yy * np.cos(rot)) / ry d = np.sqrt(u * u + v * v) xi = (int(cx) + xx) % size yi = (int(cy) + yy) % size body = d <= 1.0 edge = (d > 1.0) & (d <= 1.0 + 1.6 / rx) img[yi[edge], xi[edge]] = rim img[yi[body], xi[body]] = c if highlight is not None: top = body & (v < -0.35) & (d > 0.45) img[yi[top], xi[top]] = img[yi[top], xi[top]] * 0.4 + highlight * 0.6 def save(name, rgb, alpha=None): size = rgb.shape[0] rgba = np.ones((size, size, 4), dtype=np.float32) rgba[..., :3] = np.clip(rgb, 0, 1) if alpha is not None: rgba[..., 3] = alpha image = bpy.data.images.new(name, size, size, alpha=alpha is not None) # Blender stores rows bottom-up. image.pixels.foreach_set(rgba[::-1].ravel()) image.filepath_raw = os.path.join(OUT, name + ".png") image.file_format = "PNG" image.save() print("SAVED", image.filepath_raw) def grass(): base = hex_rgb("#2c3521") n1 = periodic_noise(SIZE, 1.6, 1)[..., None] n2 = periodic_noise(SIZE, 1.0, 2)[..., None] img = base * (0.78 + 0.45 * n1) * (0.9 + 0.2 * n2) # Olive-to-grey drift: the reference grass is dusty, not lush. grey = hex_rgb("#3a3d33") img = img * (1 - 0.35 * n2) + grey * 0.35 * n2 blades = np.array([hex_rgb(h) for h in ("#1b2214", "#242d18", "#3f4b2a", "#4f5b33", "#5d6a3c", "#6b7446")]) stamp_strokes(img, 26000, (5, 12), 3, blades[:3], 0.15, 3) stamp_strokes(img, 22000, (4, 10), 2, blades[2:], 0.18, 4) stamp_strokes(img, 5000, (3, 7), 2, blades[4:], 0.12, 5) # A few dead, yellowed blades and dark specks of soil between tufts. stamp_strokes(img, 1800, (4, 9), 2, np.array([hex_rgb("#7b7442"), hex_rgb("#6a5d38")]), 0.1, 6) specks = rng.random((SIZE, SIZE)) < 0.004 img[specks] = hex_rgb("#1a1712") # The reference grass reads grey-olive: pull 45 % of the way to luminance. luma = (img @ np.array([0.299, 0.587, 0.114]))[..., None] img = img * 0.55 + luma * 0.45 save("crater_grass", img) def dirt(): base = hex_rgb("#3b3026") n1 = periodic_noise(SIZE, 1.4, 11)[..., None] n2 = periodic_noise(SIZE, 0.7, 12)[..., None] img = base * (0.7 + 0.55 * n1) * (0.88 + 0.24 * n2) ash = hex_rgb("#2a2622") img = img * (1 - 0.4 * (1 - n1)) + ash * 0.4 * (1 - n1) stamp_blobs(img, 520, (1.8, 4.2), hex_rgb("#6d6a61"), hex_rgb("#1d1a16"), 13, hex_rgb("#9a968a")) stamp_blobs(img, 90, (4.5, 8.0), hex_rgb("#5e5c55"), hex_rgb("#1a1714"), 14, hex_rgb("#8c897f")) # Litter: pale paper flecks, rusty and red bits, a few stray blades. r = np.random.default_rng(15) for color, count in (("#b9b3a0", 260), ("#8a4b2e", 160), ("#9c2f2a", 70), ("#c9c2ad", 90)): xs = r.integers(0, SIZE, count) ys = r.integers(0, SIZE, count) for dx in range(2): for dy in range(2): img[(ys + dy) % SIZE, (xs + dx) % SIZE] = hex_rgb(color) * r.uniform(0.85, 1.1) stamp_strokes(img, 2400, (3, 8), 2, np.array([hex_rgb("#3f4b2a"), hex_rgb("#56613a")]), 0.15, 16) save("crater_dirt", img) def patch_mask(): """Where soil breaks through: soft blobs, tileable, sampled at large scale.""" n = periodic_noise(512, 2.1, 21) * 0.75 + periodic_noise(512, 1.3, 22) * 0.25 n = (n - n.min()) / (n.max() - n.min()) save_gray("crater_patches", n) def save_gray(name, g): size = g.shape[0] rgb = np.repeat(g[..., None], 3, axis=2) save(name, rgb) if __name__ == "__main__": os.makedirs(OUT, exist_ok=True) grass() dirt() patch_mask()