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	ksteube	1147	"""
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	jongui	1148	def __init__(self, scene, viewport = Viewport.SOUTH_WEST):
20	ksteube	1147	"""
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	jongui	1148	self.__vtk_camera = vtk.vtkCamera()
32	ksteube	1147
33	jongui	1148	# 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	ksteube	1147	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	jongui	1148	self.__modified = True
59	ksteube	1147
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	jongui	1148	self.__modified = True
70	ksteube	1147
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	jongui	1148	self.__modified = True
103	ksteube	1147
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	jongui	1148	self.__modified = True
120	ksteube	1147
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	jongui	1148	self.__modified = True
131	ksteube	1147
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	jongui	1148	self.__modified = True
186	ksteube	1147
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	jongui	1148
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