From 3623dd38018b36fc2d41661b4156322d15aa5c5a Mon Sep 17 00:00:00 2001
From: Nicolas <Nicolas@nonan.net>
Date: Tue, 25 Aug 2026 13:32:01 +0200
Subject: [PATCH] Fixed normalize function for quaternions

---
 src/copapy/_quaternion.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/copapy/_quaternion.py b/src/copapy/_quaternion.py
index f9b3dfe..45978c7 100644
--- a/src/copapy/_quaternion.py
+++ b/src/copapy/_quaternion.py
@@ -5,6 +5,8 @@ import copapy as cp
 from ._basic_types import NumLike, value, unifloat, ArrayType
 from ._mixed import mixed_sum
 
+epsilon = 1e-20
+
 
 class quaternion(ArrayType[float]):
     """Mathematical quaternion class for representing 3D rotations.
@@ -91,11 +93,9 @@ class quaternion(ArrayType[float]):
         """Normalize the quaternion to unit length.
 
         Returns:
-            A normalized (unit) quaternion. Returns identity if the norm is zero.
+            A normalized (unit) quaternion.
         """
-        n = self.norm()
-        if not isinstance(n, value) and n == 0:
-            return quaternion.identity()
+        n = self.norm() + epsilon
         return quaternion(v / n for v in self.values)
 
     def toRotationMatrix(self) -> tensor[float]: