Add setRotationFromMatrix to Object3D py-side

Author: vidartf

pythreejs/core/Object3D.py

@@ -1,3 +1,5 @@
+from math import pi, sqrt
+
 from ipywidgets import register
 
 from .._base.Three import ThreeWidget
@@ -30,6 +32,37 @@ def lookAt(self, vector):
     def rotateX(self, rad):
         self.exec_three_obj_method('rotateX', rad)
 
+    def rotateY(self, rad):
+        self.exec_three_obj_method('rotateY', rad)
+
+    def rotateZ(self, rad):
+        self.exec_three_obj_method('rotateZ', rad)
+
+    def setRotationFromMatrix(self, m):
+        """
+        m is a 3 by 3 matrix, as a list of rows.  The columns of this matrix are
+        the vectors x, y, and z
+        """
+        #x = self.normalize(m[0:3])
+        #y = self.normalize(m[3:6])
+        #z = self.normalize(m[6:9])
+        x = m[0:3]
+        y = m[3:6]
+        z = m[6:9]
+        trace = x[0] + y[1] + z[2]
+        if (trace > 0):
+            s = 0.5 / sqrt(trace + 1)
+            self.quaternion = [(y[2] - z[1]) * s, (z[0] - x[2]) * s, (x[1] - y[0]) * s, 0.25 / s]
+        elif (x[0] > y[1] and x[0] > z[2]):
+            s = 2.0 * sqrt(1.0 + x[0] - y[1] - z[2])
+            self.quaternion = [0.25 * s, (y[0] + x[1]) / s, (z[0] + x[2]) / s, (y[2] - z[1]) / s]
+        elif (y[1] > z[2]):
+            s = 2.0 * sqrt(1.0 + y[1] - x[0] - z[2])
+            self.quaternion = [(y[0] + x[1]) / s, 0.25 * s, (z[1] + y[2]) / s, (z[0] - x[2]) / s]
+        else:
+            s = 2.0 * sqrt(1.0 + z[2] - x[0] - y[1])
+            self.quaternion = [(z[0] + x[2]) / s, (z[1] + y[2]) / s, 0.25 * s, (x[1] - y[0]) / s]
+
     def _repr_keys(self):
         # Don't include aggregate structures in repr
         super_keys = super(Object3D, self)._repr_keys()