update

3D/animations/fetch_files.bat

@@ -0,0 +1,10 @@
+@echo off
+for %%u in (
+    "https://sketchfab.com/3d-models/540-hyper-round-9305ffbce4a348acbb830823e5390f91"
+    "https://sketchfab.com/3d-models/hook-kick-4c8dc446b6764929b65685cd3063e9bd"
+    "https://sketchfab.com/3d-models/side-kick-b6a522c83f7c4078bccc1df766cc67ab"
+    "https://sketchfab.com/3d-models/side-kick-b6a522c83f7c4078bccc1df766cc67ab"
+    "https://sketchfab.com/3d-models/540-hyper-round-9305ffbce4a348acbb830823e5390f91"
+) do (
+    python sketchfab_animation.py %%~u --overwrite
+)

3D/animations/sketchfab_animation.py

@@ -824,17 +824,21 @@ def export_animation(scene, animation, raw, clip_name, fps, scale, geometry_buff
         if key in axis_cache:
             axis = axis_cache[key]
         else:
-            theta = pole * (3.14159265359 / (nphi - 1))
+            theta = pole * (math.pi / (nphi - 1))
             cosine, sine = math.cos(theta), math.sin(theta)
-            theta += 1.57079632679 / (nphi - 1)
-            ratio = (math.cos(0.01745329251 * epsilon) - cosine * math.cos(theta)) / max(1e-5, sine * math.sin(theta))
-            ratio = max(-1, min(1, ratio))
-            phi = 6.28318530718 * azimuth / math.ceil(3.14159265359 / max(1e-5, math.acos(ratio)))
+            theta += (math.pi / 2) / (nphi - 1)
+            ratio = (
+                math.cos(math.radians(epsilon)) - cosine * math.cos(theta)
+            ) / max(1e-5, sine * math.sin(theta))
+            ratio = max(-1.0, min(1.0, ratio))
+            phi = math.tau * azimuth / math.ceil(
+                math.pi / max(1e-5, math.acos(ratio)))
             axis = (sine * math.cos(phi), sine * math.sin(phi), cosine)
             # The viewer caches axes in Float32Array; first use retains doubles.
             if 3 * (pole + nphi * azimuth) < 1801779:
                 axis_cache[key] = tuple(f32(x) for x in axis)
-        half_angle = 0.000047938362584151635 * angle
+        # Convert 15-bit integer angle to half-angle in radians ([0, pi/2])
+        half_angle = ((math.pi / 2) / 32767) * angle
         sine = math.sin(half_angle)
         return [f32(sine * x) for x in axis] + [f32(math.cos(half_angle))]