def itransformMatrix(
translation = (0,0,0),
center = (0,0,0),
rotation = (0,1,0,0),
scale = (1,1,1),
scaleOrientation = (0,1,0,0),
parentMatrix = None,
):
"""Convert VRML transform values to an inverse transform matrix
Returns 4x4 transformation matrix
Note that this uses VRML standard for rotations
(angle last, and in radians).
This should return matrices which, when applied to
parent-space coordinates, give you local-space
coordinates for the corresponding transform.
Note: this is a substantially un-tested algorithm
though it seems to be properly constructed as far
as I can see. Whether to use dot(x, parentMatrix)
or the reverse is not immediately clear to me.
parentMatrix if provided, should be the child's
transformation matrix, a 4x4 matrix of such as
returned by this function.
"""
T,T1 = transMatrix( translation )
C,C1 = transMatrix( center )
R,R1 = rotMatrix( rotation )
SO,SO1 = rotMatrix( scaleOrientation )
S,S1 = scaleMatrix( scale )
return compressMatrices( parentMatrix, C,SO, S1, SO1, R1, C1, T1)
def transformMatrix(
translation = (0,0,0),
center = (0,0,0),
rotation = (0,1,0,0),
scale = (1,1,1),
scaleOrientation = (0,1,0,0),
parentMatrix = None,
):
"""Convert VRML transform values to an overall matrix
Returns 4x4 transformation matrix
Note that this uses VRML standard for rotations
(angle last, and in radians).
This should return matrices which, when applied to
local-space coordinates, give you parent-space
coordinates.
parentMatrix if provided, should be the parent's
transformation matrix, a 4x4 matrix of such as
returned by this function.
"""
T,T1 = transMatrix( translation )
C,C1 = transMatrix( center )
R,R1 = rotMatrix( rotation )
SO,SO1 = rotMatrix( scaleOrientation )
S,S1 = scaleMatrix( scale )
return compressMatrices( parentMatrix, T,C,R,SO,S,SO1,C1 )
def localMatrices(
translation = (0,0,0),
center = (0,0,0),
rotation = (0,1,0,0),
scale = (1,1,1),
scaleOrientation = (0,1,0,0),
parentMatrix = None,
):
"""Calculate (forward,inverse) matrices for this transform element"""
T,T1 = transMatrix( translation )
C,C1 = transMatrix( center )
R,R1 = rotMatrix( rotation )
SO,SO1 = rotMatrix( scaleOrientation )
S,S1 = scaleMatrix( scale )
return (
compressMatrices( T,C,R,SO,S,SO1,C1 ),
compressMatrices( C,SO, S1, SO1, R1, C1, T1)
)
def center(
translation = (0,0,0),
center = (0,0,0),
parentMatrix = None,
):
"""Determine the center of rotation for a transform node
Returns the parent-space coordinate of the
node's center of rotation.
"""
if parentMatrix is None:
parentMatrix = identity(4)
T,T1 = transMatrix( translation )
C,C1 = transMatrix( center )
for x in (T,C):
if x:
parentMatrix = dot( x, parentMatrix)
return dot( ORIGINPOINT, parentMatrix )
def transformMatrices(
translation = (0,0,0),
center = (0,0,0),
rotation = (0,1,0,0),
scale = (1,1,1),
scaleOrientation = (0,1,0,0),
parentMatrix = None,
):
"""Calculate both forward and backward matrices for these parameters"""
T,T1 = transMatrix( translation )
C,C1 = transMatrix( center )
R,R1 = rotMatrix( rotation )
SO,SO1 = rotMatrix( scaleOrientation )
S,S1 = scaleMatrix( scale )
return (
compressMatrices( parentMatrix, T,C,R,SO,S,SO1,C1 ),
compressMatrices( parentMatrix, C,SO, S1, SO1, R1, C1, T1)
)
