- added sdf folder ( doesnt work via pip or git=)

sdf/stl.py

@@ -0,0 +1,27 @@
+import numpy as np
+import struct
+
+
+def write_binary_stl(path, points):
+    n = len(points) // 3
+
+    points = np.array(points, dtype="float32").reshape((-1, 3, 3))
+    normals = np.cross(points[:, 1] - points[:, 0], points[:, 2] - points[:, 0])
+    normals /= np.linalg.norm(normals, axis=1).reshape((-1, 1))
+
+    dtype = np.dtype(
+        [
+            ("normal", ("<f", 3)),
+            ("points", ("<f", (3, 3))),
+            ("attr", "<H"),
+        ]
+    )
+
+    a = np.zeros(n, dtype=dtype)
+    a["points"] = points
+    a["normal"] = normals
+
+    with open(path, "wb") as fp:
+        fp.write(b"\x00" * 80)
+        fp.write(struct.pack("<I", n))
+        fp.write(a.tobytes())