Section: Visualization Toolkit Rendering Classes
Lights have a type that describes how the light should move with respect to the camera. A Headlight is always located at the current camera position and shines on the camera's focal point. A CameraLight also moves with the camera, but may not be coincident to it. CameraLights are defined in a normalized coordinate space where the camera is located at (0, 0, 1), the camera is looking at (0, 0, 0), and up is (0, 1, 0). Finally, a SceneLight is part of the scene itself and does not move with the camera. (Renderers are responsible for moving the light based on its type.)
Lights have a transformation matrix that describes the space in which they are positioned. A light's world space position and focal point are defined by their local position and focal point, transformed by their transformation matrix (if it exists).
To create an instance of class vtkLight, simply invoke its constructor as follows
obj = vtkLight
obj
is an instance of the vtkLight class.
string = obj.GetClassName ()
int = obj.IsA (string name)
vtkLight = obj.NewInstance ()
vtkLight = obj.SafeDownCast (vtkObject o)
vtkLight = obj.ShallowClone ()
- Create a new light object with the same light parameters than the current
object (any ivar from the superclasses (vtkObject and vtkObjectBase),
like reference counting, timestamp and observers are not copied).
This is a shallow clone (TransformMatrix is referenced)
obj.Render (vtkRenderer , int )
- Abstract interface to renderer. Each concrete subclass of vtkLight
will load its data into the graphics system in response to this method
invocation. The actual loading is performed by a vtkLightDevice
subclass, which will get created automatically.
obj.SetAmbientColor (double , double , double )
- Set/Get the color of the light. It is possible to set the ambient,
diffuse and specular colors separately. The SetColor() method sets
the diffuse and specular colors to the same color (this is a feature
to preserve backward compatbility.)
obj.SetAmbientColor (double a[3])
- Set/Get the color of the light. It is possible to set the ambient,
diffuse and specular colors separately. The SetColor() method sets
the diffuse and specular colors to the same color (this is a feature
to preserve backward compatbility.)
double = obj. GetAmbientColor ()
- Set/Get the color of the light. It is possible to set the ambient,
diffuse and specular colors separately. The SetColor() method sets
the diffuse and specular colors to the same color (this is a feature
to preserve backward compatbility.)
obj.SetDiffuseColor (double , double , double )
- Set/Get the color of the light. It is possible to set the ambient,
diffuse and specular colors separately. The SetColor() method sets
the diffuse and specular colors to the same color (this is a feature
to preserve backward compatbility.)
obj.SetDiffuseColor (double a[3])
- Set/Get the color of the light. It is possible to set the ambient,
diffuse and specular colors separately. The SetColor() method sets
the diffuse and specular colors to the same color (this is a feature
to preserve backward compatbility.)
double = obj. GetDiffuseColor ()
- Set/Get the color of the light. It is possible to set the ambient,
diffuse and specular colors separately. The SetColor() method sets
the diffuse and specular colors to the same color (this is a feature
to preserve backward compatbility.)
obj.SetSpecularColor (double , double , double )
- Set/Get the color of the light. It is possible to set the ambient,
diffuse and specular colors separately. The SetColor() method sets
the diffuse and specular colors to the same color (this is a feature
to preserve backward compatbility.)
obj.SetSpecularColor (double a[3])
- Set/Get the color of the light. It is possible to set the ambient,
diffuse and specular colors separately. The SetColor() method sets
the diffuse and specular colors to the same color (this is a feature
to preserve backward compatbility.)
double = obj. GetSpecularColor ()
- Set/Get the color of the light. It is possible to set the ambient,
diffuse and specular colors separately. The SetColor() method sets
the diffuse and specular colors to the same color (this is a feature
to preserve backward compatbility.)
obj.SetColor (double , double , double )
- Set/Get the color of the light. It is possible to set the ambient,
diffuse and specular colors separately. The SetColor() method sets
the diffuse and specular colors to the same color (this is a feature
to preserve backward compatbility.)
obj.SetColor (double a[3])
- Set/Get the color of the light. It is possible to set the ambient,
diffuse and specular colors separately. The SetColor() method sets
the diffuse and specular colors to the same color (this is a feature
to preserve backward compatbility.)
obj.GetColor (double rgb[3])
- Set/Get the color of the light. It is possible to set the ambient,
diffuse and specular colors separately. The SetColor() method sets
the diffuse and specular colors to the same color (this is a feature
to preserve backward compatbility.)
double = obj.GetColor ()
- Set/Get the color of the light. It is possible to set the ambient,
diffuse and specular colors separately. The SetColor() method sets
the diffuse and specular colors to the same color (this is a feature
to preserve backward compatbility.)
obj.SetPosition (double , double , double )
- Set/Get the position of the light.
Note: The position of the light is defined in the coordinate
space indicated by its transformation matrix (if it exists).
Thus, to get the light's world space position, use
vtkGetTransformedPosition() instead of vtkGetPosition().
obj.SetPosition (double a[3])
- Set/Get the position of the light.
Note: The position of the light is defined in the coordinate
space indicated by its transformation matrix (if it exists).
Thus, to get the light's world space position, use
vtkGetTransformedPosition() instead of vtkGetPosition().
double = obj. GetPosition ()
- Set/Get the position of the light.
Note: The position of the light is defined in the coordinate
space indicated by its transformation matrix (if it exists).
Thus, to get the light's world space position, use
vtkGetTransformedPosition() instead of vtkGetPosition().
obj.SetPosition (float a)
- Set/Get the position of the light.
Note: The position of the light is defined in the coordinate
space indicated by its transformation matrix (if it exists).
Thus, to get the light's world space position, use
vtkGetTransformedPosition() instead of vtkGetPosition().
obj.SetFocalPoint (double , double , double )
- Set/Get the point at which the light is shining.
Note: The focal point of the light is defined in the coordinate
space indicated by its transformation matrix (if it exists).
Thus, to get the light's world space focal point, use
vtkGetTransformedFocalPoint() instead of vtkGetFocalPoint().
obj.SetFocalPoint (double a[3])
- Set/Get the point at which the light is shining.
Note: The focal point of the light is defined in the coordinate
space indicated by its transformation matrix (if it exists).
Thus, to get the light's world space focal point, use
vtkGetTransformedFocalPoint() instead of vtkGetFocalPoint().
double = obj. GetFocalPoint ()
- Set/Get the point at which the light is shining.
Note: The focal point of the light is defined in the coordinate
space indicated by its transformation matrix (if it exists).
Thus, to get the light's world space focal point, use
vtkGetTransformedFocalPoint() instead of vtkGetFocalPoint().
obj.SetFocalPoint (float a)
- Set/Get the point at which the light is shining.
Note: The focal point of the light is defined in the coordinate
space indicated by its transformation matrix (if it exists).
Thus, to get the light's world space focal point, use
vtkGetTransformedFocalPoint() instead of vtkGetFocalPoint().
obj.SetIntensity (double )
- Set/Get the brightness of the light (from one to zero).
double = obj.GetIntensity ()
- Set/Get the brightness of the light (from one to zero).
obj.SetSwitch (int )
- Turn the light on or off.
int = obj.GetSwitch ()
- Turn the light on or off.
obj.SwitchOn ()
- Turn the light on or off.
obj.SwitchOff ()
- Turn the light on or off.
obj.SetPositional (int )
- Turn positional lighting on or off.
int = obj.GetPositional ()
- Turn positional lighting on or off.
obj.PositionalOn ()
- Turn positional lighting on or off.
obj.PositionalOff ()
- Turn positional lighting on or off.
obj.SetExponent (double )
- Set/Get the exponent of the cosine used in positional lighting.
double = obj.GetExponentMinValue ()
- Set/Get the exponent of the cosine used in positional lighting.
double = obj.GetExponentMaxValue ()
- Set/Get the exponent of the cosine used in positional lighting.
double = obj.GetExponent ()
- Set/Get the exponent of the cosine used in positional lighting.
obj.SetConeAngle (double )
- Set/Get the lighting cone angle of a positional light in degrees.
This is the angle between the axis of the cone and a ray along the edge of
the cone.
A value of 180 indicates that you want no spot lighting effects
just a positional light.
double = obj.GetConeAngle ()
- Set/Get the lighting cone angle of a positional light in degrees.
This is the angle between the axis of the cone and a ray along the edge of
the cone.
A value of 180 indicates that you want no spot lighting effects
just a positional light.
obj.SetAttenuationValues (double , double , double )
- Set/Get the quadratic attenuation constants. They are specified as
constant, linear, and quadratic, in that order.
obj.SetAttenuationValues (double a[3])
- Set/Get the quadratic attenuation constants. They are specified as
constant, linear, and quadratic, in that order.
double = obj. GetAttenuationValues ()
- Set/Get the quadratic attenuation constants. They are specified as
constant, linear, and quadratic, in that order.
obj.SetTransformMatrix (vtkMatrix4x4 )
- Set/Get the light's transformation matrix. If a matrix is set for
a light, the light's parameters (position and focal point) are
transformed by the matrix before being rendered.
vtkMatrix4x4 = obj.GetTransformMatrix ()
- Set/Get the light's transformation matrix. If a matrix is set for
a light, the light's parameters (position and focal point) are
transformed by the matrix before being rendered.
obj.GetTransformedPosition (double a[3])
- Get the position of the light, modified by the transformation matrix
(if it exists).
double = obj.GetTransformedPosition ()
- Get the position of the light, modified by the transformation matrix
(if it exists).
obj.GetTransformedFocalPoint (double a[3])
- Get the focal point of the light, modified by the transformation matrix
(if it exists).
double = obj.GetTransformedFocalPoint ()
- Get the focal point of the light, modified by the transformation matrix
(if it exists).
obj.SetDirectionAngle (double elevation, double azimuth)
- Set the position and focal point of a light based on elevation and
azimuth. The light is moved so it is shining from the given angle.
Angles are given in degrees. If the light is a
positional light, it is made directional instead.
obj.SetDirectionAngle (double ang[2])
- Set the position and focal point of a light based on elevation and
azimuth. The light is moved so it is shining from the given angle.
Angles are given in degrees. If the light is a
positional light, it is made directional instead.
obj.DeepCopy (vtkLight light)
- Perform deep copy of this light.
obj.SetLightType (int )
- Set/Get the type of the light.
A SceneLight is a light located in the world coordinate space. A light
is initially created as a scene light.
A Headlight is always located at the camera and is pointed at the
camera's focal point. The renderer is free to modify the position and
focal point of the camera at any time.
A CameraLight is also attached to the camera, but is not necessarily
located at the camera's position. CameraLights are defined in a
coordinate space where the camera is located at (0, 0, 1), looking
towards (0, 0, 0) at a distance of 1, with up being (0, 1, 0).
Note: Use SetLightTypeToSceneLight, rather than SetLightType(3), since
the former clears the light's transform matrix.
int = obj.GetLightType ()
- Set/Get the type of the light.
A SceneLight is a light located in the world coordinate space. A light
is initially created as a scene light.
A Headlight is always located at the camera and is pointed at the
camera's focal point. The renderer is free to modify the position and
focal point of the camera at any time.
A CameraLight is also attached to the camera, but is not necessarily
located at the camera's position. CameraLights are defined in a
coordinate space where the camera is located at (0, 0, 1), looking
towards (0, 0, 0) at a distance of 1, with up being (0, 1, 0).
Note: Use SetLightTypeToSceneLight, rather than SetLightType(3), since
the former clears the light's transform matrix.
obj.SetLightTypeToHeadlight ()
- Set/Get the type of the light.
A SceneLight is a light located in the world coordinate space. A light
is initially created as a scene light.
A Headlight is always located at the camera and is pointed at the
camera's focal point. The renderer is free to modify the position and
focal point of the camera at any time.
A CameraLight is also attached to the camera, but is not necessarily
located at the camera's position. CameraLights are defined in a
coordinate space where the camera is located at (0, 0, 1), looking
towards (0, 0, 0) at a distance of 1, with up being (0, 1, 0).
Note: Use SetLightTypeToSceneLight, rather than SetLightType(3), since
the former clears the light's transform matrix.
obj.SetLightTypeToSceneLight ()
- Set/Get the type of the light.
A SceneLight is a light located in the world coordinate space. A light
is initially created as a scene light.
A Headlight is always located at the camera and is pointed at the
camera's focal point. The renderer is free to modify the position and
focal point of the camera at any time.
A CameraLight is also attached to the camera, but is not necessarily
located at the camera's position. CameraLights are defined in a
coordinate space where the camera is located at (0, 0, 1), looking
towards (0, 0, 0) at a distance of 1, with up being (0, 1, 0).
Note: Use SetLightTypeToSceneLight, rather than SetLightType(3), since
the former clears the light's transform matrix.
obj.SetLightTypeToCameraLight ()
- Query the type of the light.
int = obj.LightTypeIsHeadlight ()
- Query the type of the light.
int = obj.LightTypeIsSceneLight ()
- Query the type of the light.
int = obj.LightTypeIsCameraLight ()
- Query the type of the light.