pyvisi/py_src/transform.py

"""
@author: John NGUI
"""

import vtk

class Transform:
    """
    Class that defines the orientation of rendered objects.
    """

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

        # NOTE: VTK's values are not 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 rendered object to be displayed correctly. Otherwise, the 
        # rendered object 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 rendered object 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 rendered object 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 rendered object 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
        """
    
        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
        """
        
        # 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
        """

        # 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: VTK transform that is used to specify the orientation
            of objects
        """

        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 rendered objects.
10	"""
11
12	def __init__(self):
13	"""
14	Initialise the transform object.
15	"""
16
17	# NOTE: VTK's values are not accurate. Origin is not exaclty (0,0,0)
18	# 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 rendered object to be displayed correctly. Otherwise, the
21	# rendered object may just fall outside the bounding box and nothing
22	# is displayed.
23
24	self.__OFFSET_VARIANCE = 0.0000000001
25	self.__vtk_transform = vtk.vtkTransform()
26
27	def translate(self, x_offset, y_offset, z_offset):
28	"""
29	Translate the rendered object along the x, y and z-axes.
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 rendered object along the x-axis.
43	@type angle: Number
44	@param angle: Angle to rotate the camera
45	"""
46
47	self.__vtk_transform.RotateX(-angle)
48
49	def rotateY(self, angle):
50	"""
51	Rotate the rendered object along the y-axis.
52	@type angle: Number
53	@param angle: Angle to rotate the camera
54	"""
55
56	self.__vtk_transform.RotateY(angle)
57
58
59	def rotateZ(self, angle):
60	"""
61	Rotate the rendered object along the z-axis.
62	@type angle: Number
63	@param angle: Angle to rotate the camera
64	"""
65
66	self.__vtk_transform.RotateZ(angle)
67
68	def setPlaneToXY(self, offset = 0):
69	"""
70	Set the plane orthogonal to the z-axis.
71	@type offset: Number
72	@param offset: Amount to translate
73	"""
74
75	self.translate(0, 0, offset + self.__OFFSET_VARIANCE)
76
77	def setPlaneToYZ(self, offset = 0):
78	"""
79	Set the plane orthogonal to the x-axis.
80	@type offset: Number
81	@param offset: Amount to translate
82	"""
83
84	# NOTE: rotateY must come first before translate. Otherwise,
85	# the output may be incorrect.
86	self.rotateY(90)
87	self.translate(offset, 0, 0)
88
89	def setPlaneToXZ(self, offset = 0):
90	"""
91	Set the plane orthogonal to the y-axis.
92	@type offset: Number
93	@param offset: Amount to translate
94	"""
95
96	# rotateX must come first before translate. Otherwise, it won't work.
97	self.rotateX(90)
98	self.translate(0, offset, 0)
99
100	def _getTransform(self):
101	"""
102	Return the transform instance.
103	@rtype: vtkTransform
104	@return: VTK transform that is used to specify the orientation
105	of objects
106	"""
107
108	return self.__vtk_transform