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DAMASK_EICMD
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adopted math from Martin Baker to calculate quaternion from matrix representation.

This commit is contained in:
Harsha Phukan 2015-05-22 20:04:05 +00:00
parent e8fb49edc6
commit c8d774f456
1 changed files with 24 additions and 22 deletions
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46
lib/damask/orientation.py
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@ -428,50 +428,52 @@ class Quaternion:
return cls([w,x,y,z]) return cls([w,x,y,z])
## Modified Method to calculate Quaternion from Orientation Matrix, Source: http://www.euclideanspace.com/maths/geometry/rotations/conversions/matrixToQuaternion/
@classmethod @classmethod
def fromMatrix(cls, m): def fromMatrix(cls, m):
if m[0,0] + m[1,1] + m[2,2] > 0.00000001: tr=m[0,0]+m[1,1]+m[2,2]
t = m[0,0] + m[1,1] + m[2,2] + 1.0 if tr > 0.00000001:
s = 0.5/math.sqrt(t) s = math.sqrt(tr + 1.0)*2.0
return cls( return cls(
[ s*t, [ s*0.25,
(m[1,2] - m[2,1])*s, (m[2,1] - m[1,2])/s,
(m[2,0] - m[0,2])*s, (m[0,2] - m[2,0])/s,
(m[0,1] - m[1,0])*s, (m[1,0] - m[0,1])/s,
]) ])
elif m[0,0] > m[1,1] and m[0,0] > m[2,2]: elif m[0,0] > m[1,1] and m[0,0] > m[2,2]:
t = m[0,0] - m[1,1] - m[2,2] + 1.0 t = m[0,0] - m[1,1] - m[2,2] + 1.0
s = 0.5/math.sqrt(t) s = 2.0*math.sqrt(t)
return cls( return cls(
[ (m[1,2] - m[2,1])*s, [ (m[2,1] - m[1,2])/s,
s*t, s*0.25,
(m[0,1] + m[1,0])*s, (m[0,1] + m[1,0])/s,
(m[2,0] + m[0,2])*s, (m[2,0] + m[0,2])/s,
]) ])
elif m[1,1] > m[2,2]: elif m[1,1] > m[2,2]:
t = -m[0,0] + m[1,1] - m[2,2] + 1.0 t = -m[0,0] + m[1,1] - m[2,2] + 1.0
s = 0.5/math.sqrt(t) s = 2.0*math.sqrt(t)
return cls( return cls(
[ (m[2,0] - m[0,2])*s, [ (m[0,2] - m[2,0])/s,
(m[0,1] + m[1,0])*s, (m[0,1] + m[1,0])/s,
s*t, s*0.25,
(m[1,2] + m[2,1])*s, (m[1,2] + m[2,1])/s,
]) ])
else: else:
t = -m[0,0] - m[1,1] + m[2,2] + 1.0 t = -m[0,0] - m[1,1] + m[2,2] + 1.0
s = 0.5/math.sqrt(t) s = 2.0*math.sqrt(t)
return cls( return cls(
[ (m[0,1] - m[1,0])*s, [ (m[1,0] - m[0,1])/s,
(m[2,0] + m[0,2])*s, (m[2,0] + m[0,2])/s,
(m[1,2] + m[2,1])*s, (m[1,2] + m[2,1])/s,
s*t, s*0.25,
]) ])