Merge pull request #18 from CSSFrancis/feat/3d-gpu-embed-perf

Author: CSSFrancis

.gitignore

@@ -48,3 +48,6 @@ docs/_static/anywidget_config.js
 
 # Git worktrees
 .worktrees/
+
+# Generated by Sphinx-Gallery (anywidget iframe HTML) — never commit
+docs/_static/viewer_widgets/

Examples/Interactive/plot_ipf_explorer.py

@@ -0,0 +1,125 @@
+"""
+Inverse Pole Figure (IPF) Explorer
+==================================
+
+An EBSD-style orientation explorer for a synthetic polycrystal:
+
+* **Left panel** — IPF-Z orientation map, colored with the standard cubic
+  IPF key (red = ⟨001⟩, green = ⟨011⟩, blue = ⟨111⟩).  Rendered as a
+  true-color RGB image.
+* **Right panel** — the *reduced 3-D inverse pole figure*: every grain's
+  sample-Z direction, expressed in crystal coordinates and folded into the
+  cubic fundamental sector, plotted as an IPF-colored point cloud on a
+  shaded, wireframed unit sphere.
+
+Drag the crosshair on the map: the grain's orientation is marked with a
+highlighted dot on the sphere, and the sphere **rotates so that direction
+faces you**.  Drag on the sphere to orbit freely; the next crosshair move
+re-aims the camera.
+"""
+
+import numpy as np
+import anyplotlib as apl
+
+rng = np.random.default_rng(42)
+
+# ── 1. Synthetic polycrystal: nearest-seed grain map ────────────────────────
+H = W = 192
+N_GRAINS = 60
+
+seeds = rng.uniform(0, [H, W], size=(N_GRAINS, 2))
+yy, xx = np.mgrid[0:H, 0:W]
+d2 = (yy[..., None] - seeds[:, 0]) ** 2 + (xx[..., None] - seeds[:, 1]) ** 2
+grain_id = np.argmin(d2, axis=-1)                       # (H, W) labels
+
+
+# ── 2. Random orientation per grain (uniform rotations via quaternions) ─────
+def random_rotations(n):
+    """Uniform random rotation matrices, shape (n, 3, 3) (Shoemake method)."""
+    u1, u2, u3 = rng.random((3, n))
+    q = np.stack([
+        np.sqrt(1 - u1) * np.sin(2 * np.pi * u2),
+        np.sqrt(1 - u1) * np.cos(2 * np.pi * u2),
+        np.sqrt(u1) * np.sin(2 * np.pi * u3),
+        np.sqrt(u1) * np.cos(2 * np.pi * u3),
+    ], axis=1)                                          # (n, 4) unit quats
+    x, y, z, w = q.T
+    return np.stack([
+        np.stack([1 - 2 * (y * y + z * z), 2 * (x * y - z * w), 2 * (x * z + y * w)], -1),
+        np.stack([2 * (x * y + z * w), 1 - 2 * (x * x + z * z), 2 * (y * z - x * w)], -1),
+        np.stack([2 * (x * z - y * w), 2 * (y * z + x * w), 1 - 2 * (x * x + y * y)], -1),
+    ], axis=1)
+
+
+rotations = random_rotations(N_GRAINS)
+
+# Sample-Z expressed in each grain's crystal frame: d = Rᵀ · ẑ
+dirs = rotations[:, 2, :]                               # row 2 of R == Rᵀ·ẑ
+
+# ── 3. Reduce to the cubic fundamental sector and IPF-color ────────────────
+# For cubic symmetry, sorting |components| ascending lands every direction
+# in the standard 001–011–111 stereographic triangle.
+reduced = np.sort(np.abs(dirs), axis=1)                 # (a ≤ b ≤ c)
+a, b, c = reduced.T
+
+# Classic IPF key: distance to each triangle corner → R, G, B
+rgb = np.stack([c - b, b - a, a], axis=1)
+rgb /= rgb.max(axis=1, keepdims=True) + 1e-12           # vivid normalisation
+grain_rgb_u8 = (rgb * 255).astype(np.uint8)             # (N_GRAINS, 3)
+
+ipf_map = grain_rgb_u8[grain_id]                        # (H, W, 3) true-color
+
+
+# ── 4. Figure: RGB map + reduced 3-D IPF point cloud ───────────────────────
+fig, (ax_map, ax_ipf) = apl.subplots(
+    1, 2, figsize=(880, 420),
+    help="Drag the crosshair: the sphere rotates to face that grain's\n"
+         "crystal direction.  Drag the sphere to orbit freely.")
+
+vmap = ax_map.imshow(ipf_map)                           # (H, W, 3) → RGB
+vmap.set_title("IPF-Z orientation map")
+cross = vmap.add_widget("crosshair", cx=W // 2, cy=H // 2, color="#ffffff")
+
+# reduced directions live on the unit sphere → fix bounds to keep the
+# origin centred and the geometry origin-true
+vipf = ax_ipf.scatter3d(
+    reduced[:, 0], reduced[:, 1], reduced[:, 2],
+    colors=grain_rgb_u8, point_size=6,
+    x_label="[100]", y_label="[010]", z_label="[001]",
+    bounds=((-1, 1),) * 3, zoom=1.4,
+)
+vipf.set_title("Reduced 3D IPF (cubic fundamental sector)")
+# Shaded unit sphere with lat/long wireframe behind the direction vectors
+vipf.set_sphere(1.0)
+
+
+# ── 5. Crosshair → highlight + rotate-to-face ───────────────────────────────
+def face_camera(v):
+    """(azimuth°, elevation°) that aim the camera straight down *v*.
+
+    With the turntable camera, the view faces unit vector ``v`` when
+    ``el = asin(vz)`` and ``az = atan2(vx, -vy)``.
+    """
+    vx, vy, vz = v
+    el = np.degrees(np.arcsin(np.clip(vz, -1.0, 1.0)))
+    az = np.degrees(np.arctan2(vx, -vy))
+    return az, el
+
+
+def show_orientation(gid: int) -> None:
+    v = reduced[gid]
+    vipf.set_highlight(*v, color="#ffffff", size=8)
+    az, el = face_camera(v)
+    vipf.set_view(azimuth=az, elevation=el)
+
+
+@cross.add_event_handler("pointer_move")
+def on_move(event):
+    ix = int(np.clip(round(cross.cx), 0, W - 1))
+    iy = int(np.clip(round(cross.cy), 0, H - 1))
+    show_orientation(int(grain_id[iy, ix]))
+
+
+show_orientation(int(grain_id[H // 2, W // 2]))
+
+fig  # Interactive