pyvisi/py_src/transform.py

"""
@author: John NGUI
"""

import vtk

class Transform:
    """
    Class that defines the orientation of planes.
    """

    def __init__(self):
        """
        Initialise the transform object.
        """

        # NOTE: VTK's values are not 100% accurate. Origin is not exaclty 
        #(0,0,0) and normal is not exactly (0, 0, 1). There is a slight 
        # variance. As a result, a slight alteration has to be done in order 
        # for the plane to be displayed correctly. Otherwise, the 
        # plane may just fall outside the bounding box and nothing 
        # is displayed.  
        self.__OFFSET_VARIANCE = 0.0000000001
        self.__vtk_transform = vtk.vtkTransform()

    def translate(self, x_offset, y_offset, z_offset):
        """
        Translate the rendered object along the x, y and z-axes.

        @type x_offset: Number
        @param x_offset: Amount to translate along the x-axis
        @type y_offset: Number
        @param y_offset: Amount to translate along the y-axis
        @type z_offset: Number
        @param z_offset: Amount to translate along the z-axis 
        """

        self.__vtk_transform.Translate(-x_offset, -y_offset, -z_offset)
    
    def rotateX(self, angle):
        """
        Rotate the plane along the x-axis.

        @type angle: Number
        @param angle: Angle to rotate the camera
        """

        self.__vtk_transform.RotateX(-angle)

    def rotateY(self, angle):
        """
        Rotate the plane along the y-axis.

        @type angle: Number
        @param angle: Angle to rotate the camera
        """

        self.__vtk_transform.RotateY(angle)
                

    def rotateZ(self, angle):
        """
        Rotate the plane along the z-axis.

        @type angle: Number
        @param angle: Angle to rotate the camera
        """

        self.__vtk_transform.RotateZ(angle)

    def setPlaneToXY(self, offset = 0):
        """
        Set the plane orthogonal to the z-axis.

        @type offset: Number
        @param offset: Amount to translate along the z-axis
        """
    
        self.translate(0, 0, offset + self.__OFFSET_VARIANCE)

    def setPlaneToYZ(self, offset = 0):
        """
        Set the plane orthogonal to the x-axis.

        @type offset: Number
        @param offset: Amount to translate along the x-axis
        """
        
        # NOTE: rotateY must come first before translate. Otherwise, 
        # the output may be incorrect.
        self.rotateY(90) 
        self.translate(offset, 0, 0)

    def setPlaneToXZ(self, offset = 0):
        """
        Set the plane orthogonal to the y-axis.

        @type offset: Number
        @param offset: Amount to translate along the y-axis
        """

        # rotateX must come first before translate. Otherwise, it won't work.
        self.rotateX(90)
        self.translate(0, offset, 0)
    
    def _getTransform(self):
        """
        Return the transform instance.

        @rtype: vtkTransform
        @return: Transform instance that is used to specify the orientation
            of the plane
        """

        return self.__vtk_transform
1	"""
2	@author: John NGUI
3	"""
4
5	import vtk
6
7	class Transform:
8	"""
9	Class that defines the orientation of planes.
10	"""
11
12	def __init__(self):
13	"""
14	Initialise the transform object.
15	"""
16
17	# NOTE: VTK's values are not 100% accurate. Origin is not exaclty
18	#(0,0,0) and normal is not exactly (0, 0, 1). There is a slight
19	# variance. As a result, a slight alteration has to be done in order
20	# for the plane to be displayed correctly. Otherwise, the
21	# plane may just fall outside the bounding box and nothing
22	# is displayed.
23	self.__OFFSET_VARIANCE = 0.0000000001
24	self.__vtk_transform = vtk.vtkTransform()
25
26	def translate(self, x_offset, y_offset, z_offset):
27	"""
28	Translate the rendered object along the x, y and z-axes.
29
30	@type x_offset: Number
31	@param x_offset: Amount to translate along the x-axis
32	@type y_offset: Number
33	@param y_offset: Amount to translate along the y-axis
34	@type z_offset: Number
35	@param z_offset: Amount to translate along the z-axis
36	"""
37
38	self.__vtk_transform.Translate(-x_offset, -y_offset, -z_offset)
39
40	def rotateX(self, angle):
41	"""
42	Rotate the plane along the x-axis.
43
44	@type angle: Number
45	@param angle: Angle to rotate the camera
46	"""
47
48	self.__vtk_transform.RotateX(-angle)
49
50	def rotateY(self, angle):
51	"""
52	Rotate the plane along the y-axis.
53
54	@type angle: Number
55	@param angle: Angle to rotate the camera
56	"""
57
58	self.__vtk_transform.RotateY(angle)
59
60
61	def rotateZ(self, angle):
62	"""
63	Rotate the plane along the z-axis.
64
65	@type angle: Number
66	@param angle: Angle to rotate the camera
67	"""
68
69	self.__vtk_transform.RotateZ(angle)
70
71	def setPlaneToXY(self, offset = 0):
72	"""
73	Set the plane orthogonal to the z-axis.
74
75	@type offset: Number
76	@param offset: Amount to translate along the z-axis
77	"""
78
79	self.translate(0, 0, offset + self.__OFFSET_VARIANCE)
80
81	def setPlaneToYZ(self, offset = 0):
82	"""
83	Set the plane orthogonal to the x-axis.
84
85	@type offset: Number
86	@param offset: Amount to translate along the x-axis
87	"""
88
89	# NOTE: rotateY must come first before translate. Otherwise,
90	# the output may be incorrect.
91	self.rotateY(90)
92	self.translate(offset, 0, 0)
93
94	def setPlaneToXZ(self, offset = 0):
95	"""
96	Set the plane orthogonal to the y-axis.
97
98	@type offset: Number
99	@param offset: Amount to translate along the y-axis
100	"""
101
102	# rotateX must come first before translate. Otherwise, it won't work.
103	self.rotateX(90)
104	self.translate(0, offset, 0)
105
106	def _getTransform(self):
107	"""
108	Return the transform instance.
109
110	@rtype: vtkTransform
111	@return: Transform instance that is used to specify the orientation
112	of the plane
113	"""
114
115	return self.__vtk_transform