pyvisi/py_src/camera.py

"""
@author: John NGUI
"""

import vtk
from position import GlobalPosition
from constant import Viewport

class Camera:
    """
    Class that defines a camera. A camera controls the display angle of
    the rendered object and one is usually created for a
    L{Scene <scene.Scene>}. However, if a L{Scene <scene.Scene>} has four
    viewports, then a separate camera may be created for each viewport.
    """

    # The SOUTH_WEST default viewport is used when there is only one viewport.
    # This saves the user from specifying the viewport when there is only one.
    def __init__(self, scene, viewport = Viewport.SOUTH_WEST):
        """
        Initialise the camera.

        @type scene: L{Scene <scene.Scene>} object
        @param scene: Scene in which objects are to be rendered on
        @type viewport: L{Viewport <constant.Viewport>} constant
        @param viewport: Viewport in which objects are to be rendered on
        """

        self.__scene = scene
        self.__viewport = viewport
        self.__vtk_camera = vtk.vtkCamera()

        # Keeps track whether camera has been modified.
        self.__modified = True 
        # Keeps track whether the modification to the camera was due to the 
        # instantiation. If it is, then __setupCamera() method is called.
        self.__initialization = True
        self.__scene._addVisualizationModules(self)

    def __setupCamera(self):
        """
        Setup the camera.
        """

        # Assign the camera to the appropriate renderer
        self.__scene._setActiveCamera(self.__viewport, self.__vtk_camera)
        self.__resetCamera()    

    def setFocalPoint(self, position):
        """
        Set the focal point of the camera.

        @type position: L{GlobalPosition <position.GlobalPosition>} object
        @param position: Camera focal point
        """

        self.__vtk_camera.SetFocalPoint(position._getGlobalPosition())      
        self.__modified = True 

    def setPosition(self, position):
        """
        Set the position of the camera.

        @type position: L{GlobalPosition <position.GlobalPosition>} object
        @param position: Camera position
        """

        self.__vtk_camera.SetPosition(position._getGlobalPosition())
        self.__modified = True 

    def setClippingRange(self, near_clipping, far_clipping):
        """
        Set the near and far clipping plane of the camera.

        @type near_clipping: Number
        @param near_clipping: Distance to the near clipping plane
        @type far_clipping: Number
        @param far_clipping: Distance to the far clipping plane
        """
    
        self.__vtk_camera.SetClippingRange(near_clipping, far_clipping)

    def setViewUp(self, position):
        """
        Set the view up direction of the camera.

        @type position: L{GlobalPosition <position.GlobalPosition>} object
        @param position: Camera view up direction
        """

        self.__vtk_camera.SetViewUp(position._getGlobalPosition())

    def azimuth(self, angle):
        """
        Rotate the camera to the left and right.

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

        self.__vtk_camera.Azimuth(angle)
        self.__modified = True 

    def elevation(self, angle):
        """
        Rotate the camera to the top and bottom.
        
        @type angle: Number
        @param angle: Degree to rotate the camera (only between -90 and 90)
        """

        self.__vtk_camera.Elevation(angle)
        # Recompute the view up vector. If not used the elevation angle is  
        # unable to exceed 87/-87 degrees. A warning resetting the
        # view up will also be thrown and the rendered object may be incorrect.
        # With the view up recomputed, the elevation angle can reach between
        # 90/-90 degrees. Exceeding that, the rendered object may be incorrect.
        self.__vtk_camera.OrthogonalizeViewUp()
        self.__modified = True 

    def roll(self, angle):
        """
        Roll the camera to the left and right.

        @type angle: Number
        @param angle: Degree to roll the camera
        """

        self.__vtk_camera.Roll(-angle)
        self.__modified = True 

    def backView(self):
        """
        Rotate the camera to view the back of the rendered object.
        """

        self.azimuth(180)

    def topView(self):
        """
        Rotate the camera to view the top of the rendered object.
        """
        
        self.elevation(90)

    def bottomView(self):
        """
        Rotate the camera to view the bottom of the rendered object.
        """

        self.elevation(-90)

    def leftView(self):
        """
        Rotate the camera to view the left side of the rendered object.
        """

        self.azimuth(-90)

    def rightView(self):
        """
        Rotate the camera to view the right side of the rendered object.
        """

        self.azimuth(90)

    def isometricView(self):
        """
        Rotate the camera to view the isometric angle of the rendered object.
        """

        self.roll(-45)
        self.elevation(-45)
        
    def dolly(self, distance):
        """
        Move the camera towards (greater than 1) and away (less than 1) from 
        the rendered object. 

        @type distance: Number
        @param distance: Amount to move towards or away the rendered object
        """

        self.__vtk_camera.Dolly(distance)
        self.__modified = True 

    def __resetCameraClippingRange(self):
        """
        Reset the camera clipping range based on the bounds of the visible 
        actors. This ensures the rendered object is not cut-off.
        Needs to be called whenever the camera's settings are modified.
        """

        self.__scene._getRenderer()[self.__viewport].ResetCameraClippingRange() 

    def __resetCamera(self):
        """
        Repositions the camera to view the center point of the actors.
        """

        self.__scene._getRenderer()[self.__viewport].ResetCamera() 

    def _isModified(self):
        """
        Return whether the Camera has been modified.

        @rtype: Boolean
        @return: True or False
        """

        if (self.__modified == True):
            return True
        else:
            return False

    def _render(self):
        """
        Render the camera.
        """

        if(self._isModified() == True):
            # Will only be true once only when the camera is instantiated.
            if(self.__initialization == True): 
                self.__setupCamera()
                self.__initialization == False

            self.__resetCameraClippingRange()
            self.__isModified = False
            

1	"""
2	@author: John NGUI
3	"""
4
5	import vtk
6	from position import GlobalPosition
7	from constant import Viewport
8
9	class Camera:
10	"""
11	Class that defines a camera. A camera controls the display angle of
12	the rendered object and one is usually created for a
13	L{Scene <scene.Scene>}. However, if a L{Scene <scene.Scene>} has four
14	viewports, then a separate camera may be created for each viewport.
15	"""
16
17	# The SOUTH_WEST default viewport is used when there is only one viewport.
18	# This saves the user from specifying the viewport when there is only one.
19	def __init__(self, scene, viewport = Viewport.SOUTH_WEST):
20	"""
21	Initialise the camera.
22
23	@type scene: L{Scene <scene.Scene>} object
24	@param scene: Scene in which objects are to be rendered on
25	@type viewport: L{Viewport <constant.Viewport>} constant
26	@param viewport: Viewport in which objects are to be rendered on
27	"""
28
29	self.__scene = scene
30	self.__viewport = viewport
31	self.__vtk_camera = vtk.vtkCamera()
32
33	# Keeps track whether camera has been modified.
34	self.__modified = True
35	# Keeps track whether the modification to the camera was due to the
36	# instantiation. If it is, then __setupCamera() method is called.
37	self.__initialization = True
38	self.__scene._addVisualizationModules(self)
39
40	def __setupCamera(self):
41	"""
42	Setup the camera.
43	"""
44
45	# Assign the camera to the appropriate renderer
46	self.__scene._setActiveCamera(self.__viewport, self.__vtk_camera)
47	self.__resetCamera()
48
49	def setFocalPoint(self, position):
50	"""
51	Set the focal point of the camera.
52
53	@type position: L{GlobalPosition <position.GlobalPosition>} object
54	@param position: Camera focal point
55	"""
56
57	self.__vtk_camera.SetFocalPoint(position._getGlobalPosition())
58	self.__modified = True
59
60	def setPosition(self, position):
61	"""
62	Set the position of the camera.
63
64	@type position: L{GlobalPosition <position.GlobalPosition>} object
65	@param position: Camera position
66	"""
67
68	self.__vtk_camera.SetPosition(position._getGlobalPosition())
69	self.__modified = True
70
71	def setClippingRange(self, near_clipping, far_clipping):
72	"""
73	Set the near and far clipping plane of the camera.
74
75	@type near_clipping: Number
76	@param near_clipping: Distance to the near clipping plane
77	@type far_clipping: Number
78	@param far_clipping: Distance to the far clipping plane
79	"""
80
81	self.__vtk_camera.SetClippingRange(near_clipping, far_clipping)
82
83	def setViewUp(self, position):
84	"""
85	Set the view up direction of the camera.
86
87	@type position: L{GlobalPosition <position.GlobalPosition>} object
88	@param position: Camera view up direction
89	"""
90
91	self.__vtk_camera.SetViewUp(position._getGlobalPosition())
92
93	def azimuth(self, angle):
94	"""
95	Rotate the camera to the left and right.
96
97	@type angle: Number
98	@param angle: Degree to rotate the camera
99	"""
100
101	self.__vtk_camera.Azimuth(angle)
102	self.__modified = True
103
104	def elevation(self, angle):
105	"""
106	Rotate the camera to the top and bottom.
107
108	@type angle: Number
109	@param angle: Degree to rotate the camera (only between -90 and 90)
110	"""
111
112	self.__vtk_camera.Elevation(angle)
113	# Recompute the view up vector. If not used the elevation angle is
114	# unable to exceed 87/-87 degrees. A warning resetting the
115	# view up will also be thrown and the rendered object may be incorrect.
116	# With the view up recomputed, the elevation angle can reach between
117	# 90/-90 degrees. Exceeding that, the rendered object may be incorrect.
118	self.__vtk_camera.OrthogonalizeViewUp()
119	self.__modified = True
120
121	def roll(self, angle):
122	"""
123	Roll the camera to the left and right.
124
125	@type angle: Number
126	@param angle: Degree to roll the camera
127	"""
128
129	self.__vtk_camera.Roll(-angle)
130	self.__modified = True
131
132	def backView(self):
133	"""
134	Rotate the camera to view the back of the rendered object.
135	"""
136
137	self.azimuth(180)
138
139	def topView(self):
140	"""
141	Rotate the camera to view the top of the rendered object.
142	"""
143
144	self.elevation(90)
145
146	def bottomView(self):
147	"""
148	Rotate the camera to view the bottom of the rendered object.
149	"""
150
151	self.elevation(-90)
152
153	def leftView(self):
154	"""
155	Rotate the camera to view the left side of the rendered object.
156	"""
157
158	self.azimuth(-90)
159
160	def rightView(self):
161	"""
162	Rotate the camera to view the right side of the rendered object.
163	"""
164
165	self.azimuth(90)
166
167	def isometricView(self):
168	"""
169	Rotate the camera to view the isometric angle of the rendered object.
170	"""
171
172	self.roll(-45)
173	self.elevation(-45)
174
175	def dolly(self, distance):
176	"""
177	Move the camera towards (greater than 1) and away (less than 1) from
178	the rendered object.
179
180	@type distance: Number
181	@param distance: Amount to move towards or away the rendered object
182	"""
183
184	self.__vtk_camera.Dolly(distance)
185	self.__modified = True
186
187	def __resetCameraClippingRange(self):
188	"""
189	Reset the camera clipping range based on the bounds of the visible
190	actors. This ensures the rendered object is not cut-off.
191	Needs to be called whenever the camera's settings are modified.
192	"""
193
194	self.__scene._getRenderer()[self.__viewport].ResetCameraClippingRange()
195
196	def __resetCamera(self):
197	"""
198	Repositions the camera to view the center point of the actors.
199	"""
200
201	self.__scene._getRenderer()[self.__viewport].ResetCamera()
202
203	def _isModified(self):
204	"""
205	Return whether the Camera has been modified.
206
207	@rtype: Boolean
208	@return: True or False
209	"""
210
211	if (self.__modified == True):
212	return True
213	else:
214	return False
215
216	def _render(self):
217	"""
218	Render the camera.
219	"""
220
221	if(self._isModified() == True):
222	# Will only be true once only when the camera is instantiated.
223	if(self.__initialization == True):
224	self.__setupCamera()
225	self.__initialization == False
226
227	self.__resetCameraClippingRange()
228	self.__isModified = False
229
230