doc/user/pyvisi.tex

\chapter{The module \pyvisi}
\label{PYVISI CHAP}
\declaremodule{extension}{esys.pyvisi}
\modulesynopsis{Python Visualization Interface}

\section{Introduction}
\pyvisi is a Python module that is used to generate 2D and 3D visualization 
for escript and its PDE solvers: finley and bruce. This module provides 
an easy to use interface to the \VTK library (\VTKUrl). Pyvisi can be used to 
render (generate) surface maps and contours for scalar fields, arrows and 
streamlines for vector fields, and ellipsoids for tensor fields.  
There are three 
approaches for rendering an object. (1) Online - object is rendered on-screen 
with interaction capability (i.e. zoom and rotate), (2) Offline - object is 
rendered off-screen (no pop-up window) and (3) Display - object is rendered 
on-screen but with no interaction capability (on-the-fly 
animation). All three approaches have the option to save the rendered object 
as an image (i.e. jpg) and subsequently converting a series of images into a 
movie (.mpg).

The following outlines the general steps to use Pyvisi:

\begin{enumerate}
\item Create a \Scene instance - a window in which objects are to be 
rendered on.
\item Create a data input instance (i.e. \DataCollector or \ImageReader) - 
reads and loads the source data for visualization.
\item Create a data visualization instance (i.e. \Map, \Velocity, \Ellipsoid, 
\Contour, \Carpet, \StreamLine or \Image) -  proccesses and manipulates 
the source data.
\item Create a \Camera or \Light instance - controls the viewing angle and
lighting effects.
\item Render the object - using either the Online, Offline or Display approach.
\item Generate movie - converts a series of images into a movie.
\end{enumerate}
\begin{center}
\begin{math}
scene \rightarrow data \; input \rightarrow data \; visualization \rightarrow 
camera \, / \, light \rightarrow render \rightarrow movie
\end{math}
\end{center}

\section{\pyvisi Classes}
The following subsections give a brief overview of the important classes 
and some of their corresponding methods. Please refer to \ReferenceGuide for 
full details.


%#############################################################################


\subsection{Scene Classes}
This subsection details the instances used to setup the viewing environment.

\subsubsection{\Scene class}

\begin{classdesc}{Scene}{renderer = Renderer.ONLINE, num_viewport = 1, 
x_size = 1152, y_size = 864}
A scene is a window in which objects are to be rendered on. Only 
one scene needs to be created. However, a scene may be divided into four 
smaller windows called viewports (if needed). Each viewport in turn can 
render a different object. 
\end{classdesc}

The following are some of the methods available:
\begin{methoddesc}[Scene]{setBackground}{color}
Set the background color of the scene.
\end{methoddesc}

\begin{methoddesc}[Scene]{render}{image_name = None}
Render the object using either the Online, Offline or Display mode.
\end{methoddesc}

\subsubsection{\Camera class}

\begin{classdesc}{Camera}{scene, viewport = Viewport.SOUTH_WEST}
A camera controls the display angle of the rendered object and one is 
usually created for a \Scene. However, if a \Scene has four viewports, then a 
separate camera may be created for each viewport. 
\end{classdesc}

The following are some of the methods available:
\begin{methoddesc}[Camera]{setFocalPoint}{position}
Set the focal point of the camera.
\end{methoddesc}

\begin{methoddesc}[Camera]{setPosition}{position}
Set the position of the camera.
\end{methoddesc}

\begin{methoddesc}[Camera]{azimuth}{angle}
Rotate the camera to the left and right.
\end{methoddesc}

\begin{methoddesc}[Camera]{elevation}{angle}
Rotate the camera to the top and bottom (only between -90 and 90).
\end{methoddesc}

\begin{methoddesc}[Camera]{backView}{}
Rotate the camera to view the back of the rendered object.
\end{methoddesc}

\begin{methoddesc}[Camera]{topView}{}
Rotate the camera to view the top of the rendered object.
\end{methoddesc}

\begin{methoddesc}[Camera]{bottomView}{}
Rotate the camera to view the bottom of the rendered object.
\end{methoddesc}

\begin{methoddesc}[Camera]{leftView}{}
Rotate the camera to view the left side of the rendered object.
\end{methoddesc}

\begin{methoddesc}[Camera]{rightView}{}
Rotate the camera to view the right side of the rendered object.
\end{methoddesc}

\begin{methoddesc}[Camera]{isometricView}{}
Rotate the camera to view the isometric angle of the rendered object.
\end{methoddesc}

\begin{methoddesc}[Camera]{dolly}{distance}
Move the camera towards (greater than 1) the rendered object. However,
the camera is unable to be moved away from the rendered object.
\end{methoddesc}

\subsubsection{\Light class}

\begin{classdesc}{Light}{scene, viewport = Viewport.SOUTH_WEST}
A light controls the lighting effect for the rendered object and works in 
a similar way to \Camera.
\end{classdesc}

The following are some of the methods available:
\begin{methoddesc}[Light]{setColor}{color}
Set the light color.
\end{methoddesc}

\begin{methoddesc}[Light]{setFocalPoint}{position}
Set the focal point of the light.
\end{methoddesc}

\begin{methoddesc}[Light]{setPosition}{position}
Set the position of the light.
\end{methoddesc}

\begin{methoddesc}[Light]{setAngle}{elevation = 0, azimuth = 0}
An alternative to set the position and focal point of the light by using the 
elevation and azimuth.
\end{methoddesc}


%##############################################################################


\subsection{Input Classes}
\label{INPUT SEC}
This subsection details the instances used to read and load the source data
for visualization.

\subsubsection{\DataCollector class}
\begin{classdesc}{DataCollector}{source = Source.XML}
A data collector is used to read data either from a XML file (using 
\texttt{setFileName()}) or from an escript object directly (using 
\texttt{setData()}). Writing XML files are expensive, but this approach has 
the advantage given that the results can be analyzed easily after the 
simulation has completed.   
\end{classdesc}

The following are some of the methods available:
\begin{methoddesc}[DataCollector]{setFileName}{file_name}
Set the XML file name to read.
\end{methoddesc}

\begin{methoddesc}[DataCollector]{setData}{**args}
Create data using the \textless name\textgreater=\textless data\textgreater 
pairing. Assumption is made that the data will be given in the 
appropriate format.
\end{methoddesc}

\begin{methoddesc}[DataCollector]{setActiveScalar}{scalar}
Specify the scalar field to load.
\end{methoddesc}

\begin{methoddesc}[DataCollector]{setActiveVector}{vector}
Specify the vector field to load.
\end{methoddesc}

\begin{methoddesc}[DataCollector]{setActiveTensor}{tensor}
Specify the tensor field to load.
\end{methoddesc}

\subsubsection{\ImageReader class}

\begin{classdesc}{ImageReader}{format}
An image reader is used to read data from an image in a variety of formats.
\end{classdesc}

The following are some of the methods available:
\begin{methoddesc}[ImageReader]{setImageName}{image_name}
Set the image name to be read.
\end{methoddesc}

\subsubsection{\TextTwoD class}

\begin{classdesc}{Text2D}{scene, text, viewport = Viewport.SOUTH_WEST}
A two-dimensional text is used to annotate the rendered object 
(i.e. inserting titles, authors and labels).
\end{classdesc}

The following are some of the methods available:
\begin{methoddesc}[Text2D]{setFontSize}{size}
Set the 2D text size.
\end{methoddesc}

\begin{methoddesc}[Text2D]{boldOn}{}
Bold the 2D text.
\end{methoddesc}

\begin{methoddesc}[Text2D]{setColor}{color}
Set the color of the 2D text.
\end{methoddesc}

Including methods from \ActorTwoD. 


%##############################################################################


\subsection{Data Visualization Classes}
\label{DATAVIS SEC}
This subsection details the instances used to process and manipulate the source
data. The typical usage of some of the classes are also shown. 

One point to note is that the source can either be point or cell data. If the
source is cell data, a conversion to point data may or may not be
required, in order for the object to be rendered correctly.
If a conversion is needed, the 'cell_to_point' flag (see below) must 
be set to 'True', otherwise 'False' (which is the default). On occasions, an
inaccurate object may be rendered from cell data even after conversion.

\subsubsection{\Map class}

\begin{classdesc}{Map}{scene, data_collector, 
viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, cell_to_point = False,
outline = True}
Class that shows a scalar field on a domain surface. The domain surface 
can either be colored or grey-scaled, depending on the lookup table used.
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD and \DataSetMapper.

A typical usage of \Map is shown below.

\begin{python}
"""
Author: John Ngui, john.ngui@uq.edu.au
"""

# Import the necessary modules.
from esys.pyvisi import Scene, DataCollector, Map, Camera
from esys.pyvisi.constant import *
import os

PYVISI_EXAMPLE_MESHES_PATH = "data_meshes"
PYVISI_EXAMPLE_IMAGES_PATH = "data_sample_images"
X_SIZE = 800
Y_SIZE = 800

SCALAR_FIELD_POINT_DATA = "temperature"
SCALAR_FIELD_CELL_DATA = "temperature_cell"
FILE_3D = "interior_3D.xml"
IMAGE_NAME = "map.jpg"
JPG_RENDERER = Renderer.ONLINE_JPG

# Create a Scene with four viewports.
s = Scene(renderer = JPG_RENDERER, num_viewport = 4, x_size = X_SIZE, 
        y_size = Y_SIZE)

# Create a DataCollector reading from a XML file.
dc1 = DataCollector(source = Source.XML)
dc1.setFileName(file_name = os.path.join(PYVISI_EXAMPLE_MESHES_PATH, FILE_3D))
dc1.setActiveScalar(scalar = SCALAR_FIELD_POINT_DATA)

# Create a  Map for the first viewport.
m1 = Map(scene = s, data_collector = dc1, viewport = Viewport.SOUTH_WEST, 
        lut = Lut.COLOR, cell_to_point = False, outline = True)
m1.setRepresentationToWireframe()

# Create a Camera for the first viewport
c1 = Camera(scene = s, viewport = Viewport.SOUTH_WEST)
c1.isometricView()

# Create a second DataCollector reading from the same XML file but specifying
# a different scalar field.
dc2 = DataCollector(source = Source.XML)
dc2.setFileName(file_name = os.path.join(PYVISI_EXAMPLE_MESHES_PATH, FILE_3D))
dc2.setActiveScalar(scalar = SCALAR_FIELD_CELL_DATA)

# Create a Map for the third viewport.
m2 = Map(scene = s, data_collector = dc2, viewport = Viewport.NORTH_EAST, 
        lut = Lut.COLOR, cell_to_point = True, outline = True)

# Create a Camera for the third viewport
c2 = Camera(scene = s, viewport = Viewport.NORTH_EAST)

# Render the object.
s.render(image_name = os.path.join(PYVISI_EXAMPLE_IMAGES_PATH, IMAGE_NAME))
\end{python}

\subsubsection{\MapOnPlaneCut class}

\begin{classdesc}{MapOnPlaneCut}{scene, data_collector, 
viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, cell_to_point = False, 
outline = True}
This class works in a similar way to \Map, except that it shows a scalar 
field cut using a plane. The plane can be translated and rotated along the 
X, Y and Z axes.
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \Transform and \DataSetMapper.

\subsubsection{\MapOnPlaneClip class}

\begin{classdesc}{MapOnPlaneClip}{scene, data_collector,
viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, cell_to_point = False, 
outline = True}
This class works in a similar way to \MapOnPlaneCut, except that it shows a 
scalar field clipped using a plane. 
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \Transform, \Clipper and \DataSetMapper.

\subsubsection{\MapOnScalarClip class}

\begin{classdesc}{MapOnScalarClip}{scene, data_collector, 
viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, cell_to_point = False, 
outline = True}
This class works in a similar way to \Map, except that it shows a scalar 
field clipped using a scalar value. 
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \Clipper and \DataSetMapper.

\subsubsection{\MapOnScalarClipWithRotation class}

\begin{classdesc}{MapOnScalarClipWithRotation}{scene, data_collector, 
viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, cell_to_point = False}
This class works in a similar way to \Map except that it
shows a 2D scalar field clipped using a scalar value and subsequently
rotated around the z-axis to create a  3D looking effect. This class should
only be used with 2D data sets and NOT 3D.
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \Clipper, \Rotation and \DataSetMapper.

\subsubsection{\Velocity class}

\begin{classdesc}{Velocity}{scene, data_collector, arrow = Arrow.TWO_D, 
color_mode = ColorMode.VECTOR, viewport = Viewport.SOUTH_WEST,  
lut = Lut.COLOR, cell_to_point = False, outline = True}
Class that shows a vector field using arrows. The arrows can either be 
colored or grey-scaled, depending on the lookup table used. If the arrows 
are colored, there are two possible coloring modes, either using vector data or 
scalar data. Similarly, there are two possible types of arrows, either 
using two-dimensional or three-dimensional.
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \GlyphThreeD, \MaskPoints and \DataSetMapper. 

\subsubsection{\VelocityOnPlaneCut class}

\begin{classdesc}{VelocityOnPlaneCut}{scene, data_collector,
arrow = Arrow.TWO_D, color_mode = ColorMode.VECTOR, 
viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, 
cell_to_point = False, outline = True}
This class works in a similar way to \MapOnPlaneCut, except that 
it shows a vector field using arrows cut using a plane.
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \GlyphThreeD, \Transform, \MaskPoints and 
\DataSetMapper. 

A typical usage of \VelocityOnPlaneCut is shown below.

\begin{python}
"""
Author: John Ngui, john.ngui@uq.edu.au
"""

# Import the necessary modules
from esys.pyvisi import Scene, DataCollector, VelocityOnPlaneCut, Camera
from esys.pyvisi.constant import *
import os

PYVISI_EXAMPLE_MESHES_PATH = "data_meshes"
PYVISI_EXAMPLE_IMAGES_PATH = "data_sample_images"
X_SIZE = 400
Y_SIZE = 400

VECTOR_FIELD_CELL_DATA = "velocity"
FILE_3D = "interior_3D.xml"
IMAGE_NAME = "velocity.jpg"
JPG_RENDERER = Renderer.ONLINE_JPG

# Create a Scene.
s = Scene(renderer = JPG_RENDERER, num_viewport = 1, x_size = X_SIZE, 
        y_size = Y_SIZE)

# Create a DataCollector reading from a XML file.
dc1 = DataCollector(source = Source.XML)
dc1.setFileName(file_name = os.path.join(PYVISI_EXAMPLE_MESHES_PATH, FILE_3D))
dc1.setActiveVector(vector = VECTOR_FIELD_CELL_DATA)

# Create VelocityOnPlaneCut.
vopc1 = VelocityOnPlaneCut(scene = s, data_collector = dc1, 
        viewport = Viewport.SOUTH_WEST, color_mode = ColorMode.VECTOR, 
        arrow = Arrow.THREE_D, lut = Lut.COLOR, cell_to_point = False, 
        outline = True)
vopc1.setScaleFactor(scale_factor = 0.5)
vopc1.setPlaneToXY(offset = 0.5)
vopc1.setRatio(2)
vopc1.randomOn()

# Create a Camera.
c1 = Camera(scene = s, viewport = Viewport.SOUTH_WEST)
c1.isometricView()
c1.elevation(angle = -20)

# Render the object.
s.render(image_name = os.path.join(PYVISI_EXAMPLE_IMAGES_PATH, IMAGE_NAME))
\end{python}

\subsubsection{\VelocityOnPlaneClip class}

\begin{classdesc}{VelocityOnPlaneClip}{scene, data_collector, 
arrow = Arrow.TWO_D, color_mode = ColorMode.VECTOR, 
viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, 
cell_to_point = False, online = True}
This class works in a similar way to \MapOnPlaneClip, except that it shows a 
vector field using arrows clipped using a plane. 
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \GlyphThreeD, \Transform, \Clipper, 
\MaskPoints and \DataSetMapper. 

\subsubsection{\Ellipsoid class}

\begin{classdesc}{Ellipsoid}{scene, data_collector, 
viewport = Viewport = SOUTH_WEST, lut = Lut.COLOR, cell_to_point = False,
outline = True}
Class that shows a tensor field using ellipsoids. The ellipsoids can either be 
colored or grey-scaled, depending on the lookup table used. 
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \Sphere, \TensorGlyph, \MaskPoints and 
\DataSetMapper.

\subsubsection{\EllipsoidOnPlaneCut class}

\begin{classdesc}{EllipsoidOnPlaneCut}{scene, data_collector,
viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, cell_to_point = False,
outline = True}
This class works in a similar way to \MapOnPlaneCut, except that it shows
a tensor field using ellipsoids cut using a plane.
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \Sphere, \TensorGlyph, \Transform,
\MaskPoints and \DataSetMapper.

\subsubsection{\EllipsoidOnPlaneClip class}

\begin{classdesc}{EllipsoidOnPlaneClip}{scene, data_collector,
viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, cell_to_point = False, 
outline = True}
This class works in a similar way to \MapOnPlaneClip, except that it shows a 
tensor field using ellipsoids clipped using a plane.
\end{classdesc}
        
The following are some of the methods available:\\
Methods from \ActorThreeD, \Sphere, \TensorGlyph, \Transform, \Clipper,
\MaskPoints and \DataSetMapper.

A typical usage of \EllipsoidOnPlaneClip is shown below.

\begin{python}
"""
Author: John Ngui, john.ngui@uq.edu.au
"""

# Import the necessary modules
from esys.pyvisi import Scene, DataCollector, EllipsoidOnPlaneClip, Camera
from esys.pyvisi.constant import *
import os

PYVISI_EXAMPLE_MESHES_PATH = "data_meshes"
PYVISI_EXAMPLE_IMAGES_PATH = "data_sample_images"
X_SIZE = 400
Y_SIZE = 400

TENSOR_FIELD_CELL_DATA = "stress_cell"
FILE_3D = "interior_3D.xml"
IMAGE_NAME = "ellipsoid.jpg"
JPG_RENDERER = Renderer.ONLINE_JPG

# Create a Scene.
s = Scene(renderer = JPG_RENDERER, num_viewport = 1, x_size = X_SIZE, 
        y_size = Y_SIZE)

# Create a DataCollector reading from a XML file.
dc1 = DataCollector(source = Source.XML)
dc1.setFileName(file_name = os.path.join(PYVISI_EXAMPLE_MESHES_PATH, FILE_3D))
dc1.setActiveTensor(tensor = TENSOR_FIELD_CELL_DATA)

# Create an EllipsoidOnPlaneClip.
eopc1 = EllipsoidOnPlaneClip(scene = s, data_collector = dc1, 
        viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, cell_to_point = True, 
        outline = True)
eopc1.setPlaneToXY()
eopc1.setScaleFactor(scale_factor = 0.2)
eopc1.rotateX(angle = 10)

# Create a Camera.
c1 = Camera(scene = s, viewport = Viewport.SOUTH_WEST)
c1.bottomView()
c1.azimuth(angle = -90)
c1.elevation(angle = 10)

# Render the object.
s.render(image_name = os.path.join(PYVISI_EXAMPLE_IMAGES_PATH, IMAGE_NAME))
\end{python}

\subsubsection{\Contour class}

\begin{classdesc}{Contour}{scene, data_collector, 
viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, cell_to_point = False, 
outline = True}
Class that shows a scalar field using contour surfaces. The contour surfaces can
either be colored or grey-scaled, depending on the lookup table used. This
class can also be used to generate iso surfaces.
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \ContourModule and \DataSetMapper. 

A typical usage of \Contour is shown below.

\begin{python}
"""
Author: John Ngui, john.ngui@uq.edu.au
"""

# Import the necessary modules
from esys.pyvisi import Scene, DataCollector, Contour, Camera
from esys.pyvisi.constant import *
import os

PYVISI_EXAMPLE_MESHES_PATH = "data_meshes"
PYVISI_EXAMPLE_IMAGES_PATH = "data_sample_images"
X_SIZE = 400
Y_SIZE = 400

SCALAR_FIELD_POINT_DATA = "temperature"
FILE_3D = "interior_3D.xml"
IMAGE_NAME = "contour.jpg"
JPG_RENDERER = Renderer.ONLINE_JPG

# Create a Scene.
s = Scene(renderer = JPG_RENDERER, num_viewport = 1, x_size = X_SIZE, 
        y_size = Y_SIZE)

# Create a DataCollector reading a XML file.
dc1 = DataCollector(source = Source.XML)
dc1.setFileName(file_name = os.path.join(PYVISI_EXAMPLE_MESHES_PATH, FILE_3D))
dc1.setActiveScalar(scalar = SCALAR_FIELD_POINT_DATA)

# Create a Contour.
ctr1 = Contour(scene = s, data_collector = dc1, viewport = Viewport.SOUTH_WEST,
        lut = Lut.COLOR, cell_to_point = False, outline = True)
ctr1.generateContours(contours = 3)

# Create a Camera.
cam1 = Camera(scene = s, viewport = Viewport.SOUTH_WEST)
cam1.elevation(angle = -40)

# Render the object.
s.render(image_name = os.path.join(PYVISI_EXAMPLE_IMAGES_PATH, IMAGE_NAME))
\end{python}

\subsubsection{\ContourOnPlaneCut class}

\begin{classdesc}{ContourOnPlaneCut}{scene, data_collector,
viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, cell_to_point = False, 
outline = True}
This class works in a similar way to \MapOnPlaneCut, except that it shows a
scalar field using contour surfaces cut using a plane.
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \ContourModule, \Transform and \DataSetMapper. 

\subsubsection{\ContourOnPlaneClip class}

\begin{classdesc}{ContourOnPlaneClip}{scene, data_collector, 
viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, cell_to_point = False, 
outline = True}
This class works in a similar way to \MapOnPlaneClip, except that it shows a 
scalar field using contour surfaces clipped using a plane.
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \ContourModule, \Transform, \Clipper and 
\DataSetMapper. 

\subsubsection{\StreamLine class}

\begin{classdesc}{StreamLine}{scene, data_collector,
viewport = Viewport.SOUTH_WEST, color_mode = ColorMode.VECTOR, lut = Lut.COLOR,
cell_to_point = False, outline = True}
Class that shows the direction of particles of a vector field using streamlines.
The streamlines can either be colored or grey-scaled, depending on the lookup
table used. If the streamlines are colored, there are two possible coloring 
modes, either using vector data or scalar data.
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \PointSource, \StreamLineModule, \Tube and 
\DataSetMapper. 

A typical usage of \StreamLine is shown below.

\begin{python}
"""
Author: John Ngui, john.ngui@uq.edu.au
"""

# Import the necessary modules.
from esys.pyvisi import Scene, DataCollector, StreamLine, Camera 
from esys.pyvisi.constant import *
import os

PYVISI_EXAMPLE_MESHES_PATH = "data_meshes"
PYVISI_EXAMPLE_IMAGES_PATH = "data_sample_images"
X_SIZE = 400
Y_SIZE = 400

VECTOR_FIELD_CELL_DATA = "temperature"
FILE_3D = "interior_3D.xml"
IMAGE_NAME = "streamline.jpg"
JPG_RENDERER = Renderer.ONLINE_JPG

# Create a Scene.
s = Scene(renderer = JPG_RENDERER, num_viewport = 1, x_size = X_SIZE, 
        y_size = Y_SIZE)

# Create a DataCollector reading from a XML file.
dc1 = DataCollector(source = Source.XML)
dc1.setFileName(file_name = os.path.join(PYVISI_EXAMPLE_MESHES_PATH, FILE_3D))

# Create a Streamline.
sl1 = StreamLine(scene = s, data_collector = dc1,
        viewport = Viewport.SOUTH_WEST, color_mode = ColorMode.SCALAR, 
        lut = Lut.COLOR, cell_to_point = False, outline = True)
sl1.setTubeRadius(radius = 0.02)
sl1.setTubeNumberOfSides(3)
sl1.setTubeRadiusToVaryByVector()
sl1.setPointSourceRadius(0.9)

# Create a Camera.
c1 = Camera(scene = s, viewport = Viewport.SOUTH_WEST)
c1.isometricView()

# Render the object.
s.render(image_name = os.path.join(PYVISI_EXAMPLE_IMAGES_PATH, IMAGE_NAME))
\end{python}

\subsubsection{\Carpet class}

\begin{classdesc}{Carpet}{scene, data_collector,
viewport = Viewport.Viewport.SOUTH_WEST, warp_mode = WarpMode.SCALAR, 
lut = Lut.COLOR, cell_to_point = False, outline = True}
This class works in a similar way to \MapOnPlaneCut, except that it shows a 
scalar field cut on a plane and deformated (warp) along the normal. The 
plane can either be colored or grey-scaled, depending on the lookup table used. 
Similarly, the plane can be deformated either using scalar data or vector data.
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \Warp, \Transform and \DataSetMapper.

A typical usage of \Carpet is shown below.

\begin{python}
"""
Author: John Ngui, john.ngui@uq.edu.au
"""

# Import the necessary modules.
from esys.pyvisi import Scene, DataCollector, Carpet, Camera
from esys.pyvisi.constant import *
import os

PYVISI_EXAMPLE_MESHES_PATH = "data_meshes"
PYVISI_EXAMPLE_IMAGES_PATH = "data_sample_images"
X_SIZE = 400
Y_SIZE = 400

SCALAR_FIELD_CELL_DATA = "temperature_cell"
FILE_3D = "interior_3D.xml"
IMAGE_NAME = "carpet.jpg"
JPG_RENDERER = Renderer.ONLINE_JPG

# Create a Scene.
s = Scene(renderer = JPG_RENDERER, num_viewport = 1, x_size = X_SIZE, 
        y_size = Y_SIZE)

# Create a DataCollector reading from a XML file.
dc1 = DataCollector(source = Source.XML)
dc1.setFileName(file_name = os.path.join(PYVISI_EXAMPLE_MESHES_PATH, FILE_3D))
dc1.setActiveScalar(scalar = SCALAR_FIELD_CELL_DATA)

# Create a Carpet.
cpt1 = Carpet(scene = s, data_collector = dc1, viewport = Viewport.SOUTH_WEST, 
        warp_mode = WarpMode.SCALAR, lut = Lut.COLOR, cell_to_point = True,
        outline = True)
cpt1.setPlaneToXY(0.2)
cpt1.setScaleFactor(1.9)

# Create a Camera.
c1 = Camera(scene = s, viewport = Viewport.SOUTH_WEST)
c1.isometricView()

# Render the object.
s.render(image_name = os.path.join(PYVISI_EXAMPLE_IMAGES_PATH, IMAGE_NAME))
\end{python}

\subsubsection{\Legend class}

\begin{classdesc}{Legend}{scene, data_collector, 
viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, legend = LegendType.SCALAR}
Class that shows a scalar field on a domain surface. The domain surface
can either be colored or grey-scaled, depending on the lookup table used
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \ScalarBar and \DataSetMapper.

\subsubsection{\Rectangle class}

\begin{classdesc}{Rectangle}{scene, viewport = Viewport.SOUTH_WEST}
Class that generates a rectangle box.
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \CubeSource and \DataSetMapper.

\subsubsection{\Image class}

\begin{classdesc}{Image}{scene, image_reader, viewport = Viewport.SOUTH_WEST}
Class that displays an image which can be scaled (upwards and downwards) and
has interaction capability. The image can also be translated and rotated along 
the X, Y and Z axes. One of the most common use of this feature is pasting an 
image on a surface map.
\end{classdesc}

The following are some of the methods available:\\
Methods from \ActorThreeD, \PlaneSource and \Transform.

A typical usage of \Image is shown below.

\begin{python}
"""
Author: John Ngui, john.ngui@uq.edu.au
"""

# Import the necessary modules.
from esys.pyvisi import Scene, DataCollector, Map, ImageReader, Image, Camera
from esys.pyvisi import GlobalPosition
from esys.pyvisi.constant import *
import os

PYVISI_EXAMPLE_MESHES_PATH = "data_meshes"
PYVISI_EXAMPLE_IMAGES_PATH = "data_sample_images"
X_SIZE = 400
Y_SIZE = 400

SCALAR_FIELD_POINT_DATA = "temperature"
FILE_3D = "interior_3D.xml"
LOAD_IMAGE_NAME = "flinders.jpg"
SAVE_IMAGE_NAME = "image.jpg"
JPG_RENDERER = Renderer.ONLINE_JPG

# Create a Scene.
s = Scene(renderer = JPG_RENDERER, num_viewport = 1, x_size = X_SIZE, 
        y_size = Y_SIZE)

# Create a DataCollector reading from a XML file.
dc1 = DataCollector(source = Source.XML)
dc1.setFileName(file_name = os.path.join(PYVISI_EXAMPLE_MESHES_PATH, FILE_3D))

# Create a Map.
m1 = Map(scene = s, data_collector = dc1, viewport = Viewport.SOUTH_WEST,
        lut = Lut.COLOR, cell_to_point = False, outline = True)
m1.setOpacity(0.3)

# Create an ImageReader (in place of DataCollector).
ir = ImageReader(ImageFormat.JPG)
ir.setImageName(image_name =  os.path.join(PYVISI_EXAMPLE_MESHES_PATH, \
        LOAD_IMAGE_NAME))

# Create an Image.
i = Image(scene = s, image_reader = ir, viewport = Viewport.SOUTH_WEST)
i.setOpacity(opacity = 0.9)
i.translate(0,0,-1)
i.setPoint1(GlobalPosition(2,0,0))
i.setPoint2(GlobalPosition(0,2,0))

# Create a Camera. 
c1 = Camera(scene = s, viewport = Viewport.SOUTH_WEST)

# Render the image.
s.render(image_name = os.path.join(PYVISI_EXAMPLE_IMAGES_PATH, SAVE_IMAGE_NAME))
\end{python}

\subsubsection{\Logo class}

\begin{classdesc}{Logo}{scene, image_reader, viewport = Viewport.SOUTH_WEST}
Class that displays a static image, in particular a logo
(i.e. company symbol) and has NO interaction capability. The position and size
of the logo can be specified.
\end{classdesc}

The following are some of the methods available:\\
Methods from \ImageReslice and \ActorTwoD.

\subsubsection{\Movie class}

\begin{classdesc}{Movie}{parameter_file = "make_movie"}
Class that creates a file called 'make_movie' by default (if a parameter
file name is not speficied) which contains a list of parameters required
by the 'ppmtompeg' command to generate a movie from a series of images.
\end{classdesc}

The following are some of the methods available:\\
\begin{methoddesc}[Movie]{imageRange}{input_directory, first_image, last_image}
The image range from which the movie is to be generated from.
\end{methoddesc}

\begin{methoddesc}[Movie]{imageList}{input_directory, image_list}
The image list from which the movie is to be generated from.
\end{methoddesc}

\begin{methoddesc}[Movie]{makeMovie}{movie}
Generate the movie.
\end{methoddesc}

A typical usage of \Movie is shown below.

\begin{python}
"""
Author: John Ngui, john.ngui@uq.edu.au
"""

# Import the necessary modules.
from esys.pyvisi import Scene, DataCollector, Map, Camera, Velocity, Legend 
from esys.pyvisi import Movie, LocalPosition
from esys.pyvisi.constant import *
import os

PYVISI_EXAMPLE_MESHES_PATH = "data_meshes"
PYVISI_EXAMPLE_IMAGES_PATH = "data_sample_images"
X_SIZE = 800
Y_SIZE = 800

SCALAR_FIELD_POINT_DATA = "temp"
FILE_2D = "tempvel-"
IMAGE_NAME = "movie"
JPG_RENDERER = Renderer.ONLINE_JPG

# Create a Scene.
s = Scene(renderer = JPG_RENDERER, num_viewport = 1, x_size = X_SIZE, 
        y_size = Y_SIZE)

# Create a DataCollector reading from a XML file. 
dc1 = DataCollector(source = Source.XML)
dc1.setActiveScalar(scalar = SCALAR_FIELD_POINT_DATA)

# Create a Map.
m1 = Map(scene = s, data_collector = dc1, 
        viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, cell_to_point = False,
        outline = True)

# Create a Camera.
cam1 = Camera(scene = s, viewport = Viewport.SOUTH_WEST)

# Create a movie.
mov = Movie()
#lst = []

# Read in one file one after another and render the object. 
for i in range(938, 949):
    dc1.setFileName(file_name =  os.path.join(PYVISI_EXAMPLE_MESHES_PATH, \
            FILE_2D + "%06d.vtu") % i)

    s.render(image_name = os.path.join(PYVISI_EXAMPLE_IMAGES_PATH, \
            IMAGE_NAME + "%06d.jpg") % i)

    #lst.append(IMAGE_NAME + "%06d.jpg" % i)

# Images (first and last inclusive) from which the movie is to be generated.
mov.imageRange(input_directory = PYVISI_EXAMPLE_IMAGES_PATH, 
        first_image = IMAGE_NAME + "000938.jpg", 
        last_image = IMAGE_NAME + "000948.jpg")

# Alternatively, a list of images can be specified.
#mov.imageList(input_directory = PYVISI_EXAMPLE_IMAGES_PATH, image_list = lst)

# Generate the movie.
mov.makeMovie(os.path.join(PYVISI_EXAMPLE_IMAGES_PATH, "movie.mpg"))
\end{python}


%##############################################################################


\subsection{Coordinate Classes}
This subsection details the instances used to position the rendered object.

\subsubsection{\LocalPosition class}

\begin{classdesc}{LocalPosition}{x_coor, y_coor}
Class that defines the local positioning (X and Y) coordinate system (2D).
\end{classdesc}

\subsubsection{\GlobalPosition class}

\begin{classdesc}{GlobalPosition}{x_coor, y_coor, z_coor}
Class that defines the global positioning (X, Y and Z) coordinate system (3D).
\end{classdesc}


%##############################################################################


\subsection{Supporting Classes}
This subsection details the supporting classes and their corresponding methods 
inherited by the input (see Section \ref{INPUT SEC}) and data 
visualization classes (see Section \ref{DATAVIS SEC}).

\subsubsection{\ActorThreeD class}
Class that defines a 3D actor. \\

The following are some of the methods available:

\begin{methoddesc}[Actor3D]{setOpacity}{opacity}
Set the opacity (transparency) of the 3D actor.
\end{methoddesc}

\begin{methoddesc}[Actor3D]{setColor}{color}
Set the color of the 3D actor.
\end{methoddesc}

\begin{methoddesc}[Actor3D]{setRepresentationToWireframe}{}
Set the representation of the 3D actor to wireframe.
\end{methoddesc}

\subsubsection{\ActorTwoD class}
Class that defines a 2D actor. \\

The following are some of the methods available:

\begin{methoddesc}[Actor2D]{setPosition}{position}
Set the position (XY) of the 2D actor. Default position is the lower left hand
corner of the window / viewport.
\end{methoddesc}

\subsubsection{\Clipper class}
Class that defines a clipper. \\

The following are some of the methods available:

\begin{methoddesc}[Clipper]{setInsideOutOn}{}
Clips one side of the rendered object.
\end{methoddesc}

\begin{methoddesc}[Clipper]{setInsideOutOff}{}
Clips the other side of the rendered object.
\end{methoddesc}

\begin{methoddesc}[Clipper]{setClipValue}{value}
Set the scalar clip value (instead of using a plane) for the clipper.
\end{methoddesc}

\subsubsection{\ContourModule class}
Class that defines the contour module. \\

The following are some of the methods available:

\begin{methoddesc}[ContourModule]{generateContours}{contours = None, 
lower_range = None, upper_range = None}
Generate the specified number of contours within the specified range.
In order to generate an iso surface, the 'lower_range' and 'upper_range' 
must be equal.
\end{methoddesc}

\subsubsection{\GlyphThreeD class}
Class that defines 3D glyphs. \\

The following are some of the methods available:

\begin{methoddesc}[Glyph3D]{setScaleModeByVector}{}
Set the 3D glyph to scale according to the vector data.
\end{methoddesc}

\begin{methoddesc}[Glyph3D]{setScaleModeByScalar}{}
Set the 3D glyph to scale according to the scalar data.
\end{methoddesc}

\begin{methoddesc}[Glyph3D]{setScaleFactor}{scale_factor}
Set the 3D glyph scale factor.
\end{methoddesc}

\subsubsection{\TensorGlyph class}
Class that defines tensor glyphs. \\

The following are some of the methods available:

\begin{methoddesc}[TensorGlyph]{setScaleFactor}{scale_factor}
Set the scale factor for the tensor glyph.
\end{methoddesc}

\begin{methoddesc}[TensorGlyph]{setMaxScaleFactor}{max_scale_factor}
Set the maximum allowable scale factor for the tensor glyph.
\end{methoddesc}

\subsubsection{\PlaneSource class}
Class that defines a plane source.  A plane source is defined by an origin
and two other points, which form the axes (X and Y). \\

The following are some of the methods available:

\begin{methoddesc}[PlaneSource]{setPoint1}{position}
Set the first point from the origin of the plane source.
\end{methoddesc}

\begin{methoddesc}[PlaneSource]{setPoint2}{position}
Set the second point from the origin of the plane source.
\end{methoddesc}

\subsubsection{\PointSource class}
Class that defines the source (location) to generate points. The points are
generated within the radius of a sphere. \\

The following are some of the methods available:

\begin{methoddesc}[PointSource]{setPointSourceRadius}{radius}
Set the radius of the sphere.
\end{methoddesc}

\begin{methoddesc}[PointSource]{setPointSourceCenter}{center}
Set the center of the sphere.
\end{methoddesc}

\begin{methoddesc}[PointSource]{setPointSourceNumberOfPoints}{points}
Set the number of points to generate within the sphere (the larger the
number of points, the more streamlines are generated).
\end{methoddesc}

\subsubsection{\Sphere class}
Class that defines a sphere. \\

The following are some of the methods available:

\begin{methoddesc}[Sphere]{setThetaResolution}{resolution}
Set the theta resolution of the sphere.
\end{methoddesc}

\begin{methoddesc}[Sphere]{setPhiResolution}{resolution}
Set the phi resolution of the sphere.
\end{methoddesc}

\subsubsection{\StreamLineModule class}
Class that defines the streamline module. \\

The following are some of the methods available:

\begin{methoddesc}[StreamLineModule]{setMaximumPropagationTime}{time}
Set the maximum length of the streamline expressed in elapsed time.
\end{methoddesc}

\begin{methoddesc}[StreamLineModule]{setIntegrationToBothDirections}{}
Set the integration to occur both sides: forward (where the streamline
goes) and backward (where the streamline came from).
\end{methoddesc}

\subsubsection{\Transform class}
Class that defines the orientation of planes. \\

The following are some of the methods available:

\begin{methoddesc}[Transform]{translate}{x_offset, y_offset, z_offset}
Translate the rendered object along the x, y and z-axes.
\end{methoddesc}

\begin{methoddesc}[Transform]{rotateX}{angle}
Rotate the plane along the x-axis.
\end{methoddesc}

\begin{methoddesc}[Transform]{rotateY}{angle}
Rotate the plane along the y-axis.
\end{methoddesc}

\begin{methoddesc}[Transform]{rotateZ}{angle}
Rotate the plane along the z-axis.
\end{methoddesc}

\begin{methoddesc}[Transform]{setPlaneToXY}{offset = 0}
Set the plane orthogonal to the z-axis.
\end{methoddesc}

\begin{methoddesc}[Transform]{setPlaneToYZ}{offset = 0}
Set the plane orthogonal to the x-axis.
\end{methoddesc}

\begin{methoddesc}[Transform]{setPlaneToXZ}{offset = 0}
Set the plane orthogonal to the y-axis.
\end{methoddesc}

\subsubsection{\Tube class}
Class that defines the tube wrapped around the streamlines. \\

The following are some of the methods available:

\begin{methoddesc}[Tube]{setTubeRadius}{radius}
Set the radius of the tube.
\end{methoddesc}

\begin{methoddesc}[Tube]{setTubeRadiusToVaryByVector}{}
Set the radius of the tube to vary by vector data.
\end{methoddesc}

\begin{methoddesc}[Tube]{setTubeRadiusToVaryByScalar}{}
Set the radius of the tube to vary by scalar data.
\end{methoddesc}

\subsubsection{\Warp class}
Class that defines the deformation of a scalar field. \\

The following are some of the methods available:

\begin{methoddesc}[Warp]{setScaleFactor}{scale_factor}
Set the displacement scale factor.
\end{methoddesc}

\subsubsection{\MaskPoints class}
Class that defines the masking of points 
every n'th point.  This is useful to prevent the rendered object
from being cluttered with arrows or ellipsoids. \\

The following are some of the methods available:

\begin{methoddesc}[MaskPoints]{setRatio}{ratio}
Mask every n'th point.
\end{methoddesc}

\begin{methoddesc}[MaskPoints]{randomOn}{}
Enables the randomization of the points selected for masking.
\end{methoddesc}

\subsubsection{\ScalarBar class}
Class that defines a scalar bar. \\

The following are some of the methods available:

\begin{methoddesc}[ScalarBar]{setTitle}{title}
Set the title of the scalar bar.
\end{methoddesc}

\begin{methoddesc}[ScalarBar]{setPosition}{position}
Set the local position of the scalar bar.
\end{methoddesc}

\begin{methoddesc}[ScalarBar]{setOrientationToHorizontal}{}
Set the orientation of the scalar bar to horizontal.
\end{methoddesc}

\begin{methoddesc}[ScalarBar]{setOrientationToVertical}{}
Set the orientation of the scalar bar to vertical.
\end{methoddesc}

\begin{methoddesc}[ScalarBar]{setHeight}{height}
Set the height of the scalar bar.
\end{methoddesc}

\begin{methoddesc}[ScalarBar]{setWidth}{width}
Set the width of the scalar bar.
\end{methoddesc}

\begin{methoddesc}[ScalarBar]{setLabelColor}{color}
Set the color of the scalar bar's label.
\end{methoddesc}

\begin{methoddesc}[ScalarBar]{setTitleColor}{color}
Set the color of the scalar bar's title.
\end{methoddesc}

\subsubsection{\ImageReslice class}
Class that defines an image reslice used to resize static
(no interaction capability) images (i.e. logo). \\

The following are some of the methods available:

\begin{methoddesc}[ImageReslice]{setSize}{size}
Set the size of the image (logo in particular), between 0 and 2. Size 1 (one) 
displays the image in its original size (which is the default).
\end{methoddesc}

\subsubsection{\DataSetMapper class}
Class that defines a data set mapper. \\

The following are some of the methods available:

\begin{methoddesc}[DataSetMapper]{setScalarRange}{lower_range, upper_range}
Set the minimum and maximium scalar range for the data set mapper. This
method is called when the range has been specified by the user.
Therefore, the scalar range read from the source will be ignored.
\end{methoddesc}

\subsubsection{\CubeSource class}
Class that defines a cube source. The center of the cube souce defines
the point from which the cube is to be generated and the X, Y
and Z lengths define the length of the cube from the center point. If
X length is 3, then the X length to the left and right of the center
point is 1.5 respectively.\\ 

The following are some of the methods available:

\begin{methoddesc}[CubeSource]{setCenter}{center}
Set the cube source center.
\end{methoddesc}

\begin{methoddesc}[CubeSource]{setXLength}{length}
Set the cube source length along the x-axis.
\end{methoddesc}

\begin{methoddesc}[CubeSource]{setYLength}{length}
Set the cube source length along the y-axis.
\end{methoddesc}

\begin{methoddesc}[CubeSource]{setZLength}{length}
Set the cube source length along the z-axis.
\end{methoddesc}

\subsubsection{\Rotation class}
Class that sweeps 2D data around the z-axis to create a 3D looking effect. \\

The following are some of the methods available:

\begin{methoddesc}[Rotation]{setResolution}{resolution}
Set the resolution of the sweep for the rotation, which controls the
number of intermediate points
\end{methoddesc}

\begin{methoddesc}[Rotation]{setAngle}{angle}
Set the angle of rotation.
\end{methoddesc}


% ############################################################################# 


\section{More Examples}
This section shows more examples.

\textsf{Reading A Series of Files}

\begin{python}
"""
Author: John Ngui, john.ngui@uq.edu.au
"""

# Import the necessary modules.
from esys.pyvisi import Scene, DataCollector, Contour, Camera 
from esys.pyvisi.constant import *
import os

PYVISI_EXAMPLE_MESHES_PATH = "data_meshes"
PYVISI_EXAMPLE_IMAGES_PATH = "data_sample_images"
X_SIZE = 400
Y_SIZE = 300

SCALAR_FIELD_POINT_DATA_1 = "lava"
SCALAR_FIELD_POINT_DATA_2 = "talus"
FILE_2D = "phi_talus_lava."

IMAGE_NAME = "seriesofreads"
JPG_RENDERER = Renderer.ONLINE_JPG

# Create a Scene.
s = Scene(renderer = JPG_RENDERER, num_viewport = 1, x_size = X_SIZE, 
        y_size = Y_SIZE)

# Create a DataCollector reading from a XML file. 
dc1 = DataCollector(source = Source.XML)
dc1.setActiveScalar(scalar = SCALAR_FIELD_POINT_DATA_1)

# Create a Contour.
mosc1 = Contour(scene = s, data_collector = dc1, 
        viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, cell_to_point = False,
        outline = True)
mosc1.generateContours(0)

# Create a second DataCollector reading from the same XML file
# but specifying a different scalar field. 
dc2 = DataCollector(source = Source.XML)
dc2.setActiveScalar(scalar = SCALAR_FIELD_POINT_DATA_2)

# Create a second Contour.
mosc2 = Contour(scene = s, data_collector = dc2, 
        viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, cell_to_point = False,
        outline = True)
mosc2.generateContours(0)

# Create a Camera.
cam1 = Camera(scene = s, viewport = Viewport.SOUTH_WEST)

# Read in one file one after another and render the object. 
for i in range(99, 104):
    dc1.setFileName(file_name =  os.path.join(PYVISI_EXAMPLE_MESHES_PATH, \
            FILE_2D + "%04d.vtu") % i)
    dc2.setFileName(file_name =  os.path.join(PYVISI_EXAMPLE_MESHES_PATH, \
            FILE_2D + "%04d.vtu") % i)

    s.render(image_name = os.path.join(PYVISI_EXAMPLE_IMAGES_PATH, \
            IMAGE_NAME + "%04d.jpg") % i)
\end{python}

\textsf{Manipulating A Single File with A Series of Translation}

\begin{python}
"""
Author: John Ngui, john.ngui@uq.edu.au
"""

# Import the necessary modules.
from esys.pyvisi import Scene, DataCollector, MapOnPlaneCut, Camera
from esys.pyvisi.constant import *
import os

PYVISI_EXAMPLE_MESHES_PATH = "data_meshes"
PYVISI_EXAMPLE_IMAGES_PATH = "data_sample_images"
X_SIZE = 400
Y_SIZE = 400

SCALAR_FIELD_POINT_DATA = "temperature"
FILE_3D = "interior_3D.xml"
IMAGE_NAME = "seriesofcuts"
JPG_RENDERER = Renderer.ONLINE_JPG

# Create a Scene.
s = Scene(renderer = JPG_RENDERER, num_viewport = 1, x_size = X_SIZE, 
        y_size = Y_SIZE)

# Create a DataCollector reading from a XML file.
dc1 = DataCollector(source = Source.XML)
dc1.setFileName(file_name = os.path.join(PYVISI_EXAMPLE_MESHES_PATH, FILE_3D))
dc1.setActiveScalar(scalar = SCALAR_FIELD_POINT_DATA)

# Create a MapOnPlaneCut.
mopc1 = MapOnPlaneCut(scene = s, data_collector = dc1, 
        viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, cell_to_point = False,
        outline = True)
mopc1.setPlaneToYZ(offset = 0.1)

# Create a Camera.
c1 = Camera(scene = s, viewport = Viewport.SOUTH_WEST)
c1.isometricView()

# Render the object with multiple cuts using a series of translation.
for i in range(0, 5):
    s.render(image_name = os.path.join(PYVISI_EXAMPLE_IMAGES_PATH, IMAGE_NAME +
            "%02d.jpg") % i)
    mopc1.translate(0.6,0,0)
\end{python}

\textsf{Reading Data Directly from Escript Objects}

\begin{python}
"""
Author: Lutz Gross, l.gross@uq.edu.au
Author: John Ngui, john.ngui@uq.edu.au
"""

# Import the necessary modules.
from esys.escript import *
from esys.escript.linearPDEs import LinearPDE
from esys.finley import Rectangle
from esys.pyvisi import Scene, DataCollector, Map, Camera
from esys.pyvisi.constant import *
import os

PYVISI_EXAMPLE_IMAGES_PATH = "data_sample_images"
X_SIZE = 400
Y_SIZE = 400
JPG_RENDERER = Renderer.ONLINE_JPG

#... set some parameters ...
xc=[0.02,0.002]
r=0.001
qc=50.e6
Tref=0.
rhocp=2.6e6
eta=75.
kappa=240.
tend=5.
# ... time, time step size and counter ...
t=0
h=0.1
i=0

#... generate domain ...
mydomain = Rectangle(l0=0.05,l1=0.01,n0=250, n1=50)
#... open PDE ...
mypde=LinearPDE(mydomain)
mypde.setSymmetryOn()
mypde.setValue(A=kappa*kronecker(mydomain),D=rhocp/h,d=eta,y=eta*Tref)
# ... set heat source: ....
x=mydomain.getX()
qH=qc*whereNegative(length(x-xc)-r)
# ... set initial temperature ....
T=Tref

# Create a Scene.
s = Scene(renderer = JPG_RENDERER, x_size = X_SIZE, y_size = Y_SIZE)

# Create a DataCollector reading directly from escript objects.
dc = DataCollector(source = Source.ESCRIPT)

# Create a Map.
m = Map(scene = s, data_collector = dc, \
        viewport = Viewport.SOUTH_WEST, lut = Lut.COLOR, \
        cell_to_point = False, outline = True)

# Create a Camera.
c = Camera(scene = s, viewport = Viewport.SOUTH_WEST)

# ... start iteration:
while t<0.4:
      i+=1
      t+=h
      mypde.setValue(Y=qH+rhocp/h*T)
      T=mypde.getSolution()

      dc.setData(temp = T)
      
      # Render the object.
      s.render(image_name = os.path.join(PYVISI_EXAMPLE_IMAGES_PATH, \
              "diffusion%02d.jpg") % i)
\end{python}

\newpage

\section{Useful Keys}
This section shows some of the useful keys when interacting with the rendered
object (in the Online approach).

\begin{table}[ht]
\begin{center}
\begin{tabular}{| c | p{13cm} |}
\hline
\textbf{Key} & \textbf{Description} \\ \hline
Keypress 'c' / 'a' & Toggle between the camera ('c') and object ('a')  mode. In 
camera mode, mouse events affect the camera position and focal point. In 
object mode, mouse events affect the rendered object's element (i.e.
cut surface map, clipped velocity field, streamline, etc) that is under the 
mouse pointer.\\ \hline
Mouse button 1 & Rotate the camera around its focal point (if in camera mode) 
or rotate the rendered object's element (if in object mode).\\ \hline
Mourse button 2 & Pan the camera (if in camera mode) or translate the rendered 
object's element (if in object mode). \\ \hline
Mouse button 3 & Zoom the camera (if in camera mode) or scale the rendered 
object's element (if in object mode). \\ \hline
Keypress 3 & Toggle the render window in and out of stereo mode. By default,
red-blue stereo pairs are created. \\ \hline
Keypress 'e' / 'q' & Exit the application if only one file is to be read, or 
read and display the next file if multiple files are to be read. \\ \hline
Keypress 's' & Modify the representation of the rendered object to surfaces.
\\ \hline
Keypress 'w' & Modify the representation of the rendered object to wireframe.
\\ \hline
Keypress 'r' & Reset the position of the rendered object to the center.
\\ \hline
\end{tabular}
\caption{Useful keys}
\end{center}
\end{table}


% ############################################################################


\newpage

\section{Sample Output}
This section displays some of the sample output by Pyvisi.  

\begin{table}[ht]
\begin{tabular}{c c c}
\includegraphics[width=\thumbnailwidth]{figures/Map} &
\includegraphics[width=\thumbnailwidth]{figures/MapOnPlaneCut} &
\includegraphics[width=\thumbnailwidth]{figures/MapOnPlaneClip} \\
Map & MapOnPlaneCut & MapOnPlaneClip \\ 
\includegraphics[width=\thumbnailwidth]{figures/MapOnScalarClip} & 
\includegraphics[width=\thumbnailwidth]{figures/MapOnScalarClipWithRotation} & 
\includegraphics[width=\thumbnailwidth]{figures/Velocity} \\ 
MapOnScalarClip & MapOnScalarClipWithRotation & Velocity \\ \\ \\ \\
\includegraphics[width=\thumbnailwidth]{figures/VelocityOnPlaneCut} & 
\includegraphics[width=\thumbnailwidth]{figures/VelocityOnPlaneClip} & 
\includegraphics[width=\thumbnailwidth]{figures/Ellipsoid} \\ 
VelocityOnPlaneCut & VelocityOnPlaneClip & Ellipsoid \\ \\ \\ \\
\includegraphics[width=\thumbnailwidth]{figures/EllipsoidOnPlaneCut} & 
\includegraphics[width=\thumbnailwidth]{figures/EllipsoidOnPlaneClip} \\ 
EllipsoidOnPlaneCut & EllipsoidOnPlaneClip \\ \\ \\ \\
\end{tabular}
\caption{Sample output}
\end{table}

\begin{table}[t]
\begin{tabular}{c c c}
\includegraphics[width=\thumbnailwidth]{figures/Contour} & 
\includegraphics[width=\thumbnailwidth]{figures/ContourOnPlaneCut} & 
\includegraphics[width=\thumbnailwidth]{figures/ContourOnPlaneClip} \\ 
Contour & ContourOnPlaneCut & ContourOnPlaneClip\\ \\  
\includegraphics[width=\thumbnailwidth]{figures/StreamLine} & 
\includegraphics[width=\thumbnailwidth]{figures/Carpet} & 
\includegraphics[width=\thumbnailwidth]{figures/Rectangle} \\ 
Streamline & Carpet & Rectangle \\ \\ \\
\includegraphics[width=\thumbnailwidth]{figures/Text} & 
\includegraphics[width=\thumbnailwidth]{figures/Logo} & 
\includegraphics[width=\thumbnailwidth]{figures/Image} \\ 
Text & Logo & Image \\ \\
\includegraphics[width=\thumbnailwidth]{figures/Legend} \\
Legend \\ \\
\end{tabular}
\caption{Sample Output}
\end{table}

