{
  "title": "Basalt Volcanic Sand",
  "origin": "AI-generated with built-in image_gen; prepared by Locker3d",
  "date": "2026-11-12",
  "resolution": [
    1024,
    1024
  ],
  "license": "CC0-1.0, following the official Locker3d texture policy",
  "prompt": "Generate one square photoreal PBR base-color source: perpendicular orthographic macro photograph of a level bed of compacted black basaltic volcanic SAND, filling the frame edge to edge. It represents a small 25\u00e2\u20ac\u201c30 cm square surface sample. The surface is made of very numerous tiny, predominantly 0.3 to 1.3 mm angular mineral grains, submillimetre fine particles filling their interstices, and a small proportion of slightly larger 1.5\u00e2\u20ac\u201c2 mm sharp fragments. Render the densely packed grains clearly: broken fine triangular facets, irregular jagged outlines, little charcoal slate and graphite gradations within individual grains, with very occasional tiny muted gray grains that do not sparkle. Deep gray-black with enough tonal separation to see individual particles, a dry matte diffuse appearance. Uniform distribution at swatch scale, individual natural size and orientation variation without organized clumps, smooth surface elevation, with fine grain detail rather than rounded pebbles, stones, coarse vesicular scoria, or the continuous face of a rock. No beach ripples, cracks, footprints, wind streaks, channels, shells, plants, wet sheen, muddy crust, gravel piles, bright white dots or directional pattern. Keep the top-down view in focus edge to edge. Neutral flat cross-polarized diffuse illumination, no hotspot, no hard cast shadows, no vignette, no gradients, no baked reflection. Repeating-texture field with consistent tone and grain density across the opposing edges and no dominant motif; no visible border, labels, charts, scale bar, scene or objects. Photographic microtexture, one full-bleed square image only.",
  "maps": [
    {
      "file": "textures/albedo.png",
      "colorSpace": "sRGB",
      "bytes": 2238338,
      "sha256": "eb6a28bb3f66a0079c5495ad89f2746ee7d77d083d316e567766aa989c3e6eb9"
    },
    {
      "file": "textures/normal-gl.png",
      "colorSpace": "Non-Color",
      "bytes": 1689860,
      "sha256": "4ea750956c00c7c284e8de4f9361966bb087ffb36acc372bf7d6c0f57b403393"
    },
    {
      "file": "textures/roughness.png",
      "colorSpace": "Non-Color",
      "bytes": 349341,
      "sha256": "277eaaa59365ff849ae7b716698dcf13961cfeb69b11010df07a0cdaece7c833"
    }
  ],
  "method": "Cropped the source to reduce pattern phase mismatch at tile edges. Albedo: periodic-plus-smooth decomposition via FFT Poisson solve to reduce edge mismatch. Normal: periodic multi-scale Gaussian bands, robust contrast normalization, material-specific cavity/joint masks and central-difference tangent-space gradients. Roughness: material preset plus local detail and joint variation. All data channels are estimates, not measured surface response.",
  "limits": "Not a photoscan. No AO, displacement or metallic maps. Generated images are not guaranteed seamless; inspect repetition at your target scale. No measured physical scale; demo scale is illustrative.",
  "edgeDiagnostics": {
    "leftRightMeanAbsRGB": 8.594,
    "topBottomMeanAbsRGB": 8.248
  },
  "suggestedTileMeters": 0.24,
  "metallicConstant": 0,
  "normalStrength": 0.62,
  "albedoCrop": {
    "boundsPixels": [
      24,
      32,
      1096,
      1104
    ],
    "coordinateOrder": "left, top, right, bottom"
  },
  "beforeEdgeDiagnostics": {
    "leftRightMeanAbsRGB": 30.952,
    "topBottomMeanAbsRGB": 28.828
  }
}