Canadian Geographic Explorer/Canadian Geographic Explorer.iso/pc/comp.z/FLY.HLP

Text File | 1996-08-27 | 48.7 KB | 1,256 lines

@title{FLY}{FLY! Users Manual}
@keyword{FLY}

 FLY! is a visualization tool which renders perspective scenes from
 elevation data. Using proprietary, high speed algorithms, successive
 scenes can be generated to give the appearance of flying through the
 data sets.

 Typically an image taken from a satellite is draped over elevation
 data and FLY! is used to fly through the data from a person's
 perspective on the ground.

 The user has full control over the flying elevation, direction and
 speed. Rendered scenes can be saved to disk in a variety of file
 formats for later use. A simple flight plan can be made to fly
 through the terrain.

 Sources of data include: satellite (Landsat, Spot, ...), air photo,
 scanners, and GIS systems.

1    Copyright
@keyword{Copyright}
@index{Copyright Notice}

       FLY!, Version 6.0, Release date: December 1, 1995

                           COPYRIGHT

 Software copyrighted (c) by PCI, 50 West Wilmot St., Richmond
 Hill, Ontario, CANADA, L4B 1M5. Tel: [phone]

                       RESTRICTED RIGHTS

                      CANADIAN GOVERNMENT

 Use, duplication, or disclosure is subject to restrictions as set
 forth in DSS 9400-18 `General Conditions - Short Form - Licensed
 Software'.

                       U.S. GOVERNMENT

 Use, duplication, or disclosure is subject to restrictions as set
 forth in FAR clause 52.227-19 `Commercial Computer Software -
 Restricted Rights' and in subparagraph (c) (1) (ii) of the
 `Rights in Technical Data and Computer Software Clause' at DFARS
 52.227-7013.

1    Command Line
@keyword{Command Line}

 FLY! can be started automatically through the use of command line
 switches.

 The following switches are used to specify the files for colour and
 elevation information.

@verbatim
 -file file
@end

 Named file is any supported GDB file (except for raw files).

@verbatim
 -chan e
 -chan grey e
 -chan r g b e
@end

 Numbers r, g, b, grey and e give channels holding colour and
 elevation. If only one number is given, it is assumed to be
 an elevation channel to be loaded as a color shaded relief terrain.
 If only two numbers are given then first is grey intensity and
 second is elevation. If all four channels are specified, it is
 interpreted as red, green, blue and elevation channels.

 The following option switches are supported:

@verbatim
 -pixelsize size
@end

 Give the size of a pixel on the ground in metres. Pixels are
 assumed to be square. Default is 30 metres or taken from the file
 (if PCIDSK).

@verbatim
 -pixelheight size
@end

 Gives step resolution of elevation data. Default is 1.0 metre.

@verbatim
 -frame xsize ysize
@end

 Gives size of output window in which rendered frames appear.
 Default is 320 by 240.

@verbatim
 -heightmag factor
@end

 Scaling factor for elevation values. Valid values are from 0.0
 to 3.0. Default is 1.0

@verbatim
 -xy x y
@end

 Gives initial position. The x, y values are in pixels. Default is to start
 at upper left corner.

@verbatim
 -z z
@end

 Gives initial height. The z value is in elevation units (i.e. whatever the
 DEM data represents). Default is 0.

@verbatim
 -dir direction
@end

 Gives initial viewing direction in degrees. Default is 180.

@verbatim
 -zoom factor
@end

 Indicates percentage zoom foreground pixels. Valid values are
 from 0 to 100. Default is 100.

@verbatim
 -tilt angle
@end

 Gives amount of tilt (position of horizion). Value is in degrees
 from 0 to 60. Default is 25.

@verbatim
 -frustum angle
@end

 Gives cone of view (in degrees) for rendered frames. Range is
 0 to 120. Default is 60.

@verbatim
 -3d
@end

 Forces the system to go into 3D anaglyph mode.

@verbatim
 -linear
@end

 Linear enhancement.

@verbatim
 -root
@end

 Root enhancement.

@verbatim
 -equal
@end

 Equalization enhancement.

@verbatim
 -blocky
@end

 Blocky quality.

@verbatim
 -fitted
@end

 Fitted quality.

@verbatim
 -smooth
@end

 Smooth quality.

@verbatim
 -shadedir angle
@end

 Shaded relief direction.

@verbatim
 -shadeinc angle
@end

 Shaded relief inclination angle.

@verbatim
 -help
@end

 Display command line options.

@verbatim
 -version
@end

 Display version number.

 Example:

@verbatim
  fly -file flydata.pix -chan 4 2 3 5 -linear -heightmag 2 -xy 512 10
      -z 400 -dir 180 -tilt 30
@end

 This loads the file flydata.pix and uses channels 4, 2 and 3 for the
 red, green and blue and channel 5 for the elevation. It performs a linear
 enhancement on the color data and stretches the elevation by a factor
 of 2. When FLY! starts up, the viewer is placed at position 512, 10
 with an elevation of 400 and looking at a direction of 180 degrees.
 The tilt angle is 30 degrees.

 See Also: {GDB}GDB Formats

1    Motif Customization
@keyword{Customization}{Fonts}
@index{Customizing FLY!}

 Customizing the appearance of FLY! on X/Motif systems.

 FLY! resources, such as fonts and colours, can be customized on
 operating systems which use X-Windows Motif, through the .Xdefaults
 file which resides in the user's login directory. The resources
 available are as follows:

  fly*fontList:              <font>   (e.g., fixed)

 General purpose font for most of the application.

  fly*fixedFont:             <font>   (e.g., 10x20)

 Font used in areas requiring monospaced characters (e.g. main text
 in help panel).

  fly*background:            <colour>  (e.g., grey)

 Background colour for most panels.

  fly*MenuBar*background:    <colour>  (e.g., thistle)

 Colour of all menu bars.

  fly*TitleBar*background:   <colour>  (e.g., lightsteelblue)

 Colour for all title bars.

 Available fonts and colours will depend on your system. Under some
 environments (such as HP VUE), customization is handled by means other
 than the .Xdefaults file. See the operating system user documentation for
 these environments.

 To set these resources system wide, an app-default file may be
 created called `fly', with the same format as the .Xdefaults
 file. It is typically placed in the directory /usr/lib/X11/app-defaults.

1    Main Panel
@keyword{Main Panel}

 The main panel consists of a menubar, some icon buttons and a message
 area.

 The menubar has three main submenus: 'File', 'Edit' and 'Options'. The 'File'
 menu is used to access functions involving disk files such as loading
 databases and saving renderings. The 'Edit' menu contains panels which allow
 the direct editing of rendering parameters like position, size and
 perspective. Using the 'Options' menu, the user can alter other aspects
 like quality and rendering mode. The menubar also contains a 'Help'
 menu for accessing the on-line help.

 There are four icons buttons. When the pointer is moved over one of the
 icon buttons, text will appear in the message area indicating what the
 button does.

 The first icon pops up the control panel. This panel provides a graphical
 interface for changing parameters like position, direction and speed. The
 second icon puts FLY! into user controlled free flight. In this mode,
 the viewer is constantly moving and flight can be controlled interactively.
 The third icon pops up the nadir panel. This provides an overhead view of
 the terrain and also allows the viewing of a flight path. The fourth
 icon button is used to access the flight editing panel. Using this panel,
 a flight path can be created. This panel also controls flight playback.

 When an icon button is pressed, its corresponding panel is popped up. In
 the case of user free flight, pressing the button sets FLY! into a
 special mode. While the panel or mode is active, the button will remain
 pressed in. When the panel is popped down or the free flight mode is
 disabled, the button pops back out.

 The message area at the bottom of the main panel will stretch if the
 main panel is resized. It is used to display brief messages as well
 as show the progress of some actions. When the mouse is moved over
 an icon button, some descriptive text will appear in the message area.

1    Menu Bar
@keyword{Menubar}

 The menubar is composed of the 'File', 'Edit' and 'Options' menus.

2    File
@keyword{Database}{Load}{Save}{Flight}

 This menu contains the following items:

 Load Database

 - Load DEM Shade RGB: Load DEM file and use shaded relief to generate colour.
 - Load DEM Shade BW: Load DEM file and use shaded relief to generate
                      grey scale.
 - Load DEM + RGB: Load terrain using DEM and RGB from a file.
 - Load DEM + BW: Load terrain using DEM and grey scale from a file.

 Save Rendering
 - Save To File: Save the current rendering to a file.

 Flight Path
 - Save Flight Path: Save the current flight path to a file.
 - Load Flight Path: Load flight path from a file.

 See Also: {..|..|}Load Terrain From Elevation Only,
       {..|..|}Load Terrain from Elevation and Colour,
       {..|..|}Save Rendering,
       {..|..|Flight Panel|Loading/Saving}Save/Load Flight Path

2    Edit
@keyword{Position}{Direction}{Speed}{Size}{Perspective}{3D}

 This menu contains the following items:

 - Position, Direction, Speed: Set position, direction or speed manually.
 - Rendering Size: Set rendering size manually.
 - Perspective: Set perspective parameters manually.
 - 3D: Set 3D rendering parameters manually.

 See Also: {..|..|}Change Position/Speed/Direction,
       {..|..|}Change Render Size,
       {..|..|}Change Perspective,
       {..|..|}Change 3D

2    Options
@keyword{Elevation}{Speed}{FPS}{Frames Per Second}{Coordinates}{Units}{Quality}
@keyword{Mode}

 This menu contains the following items:

 - Elevation Options: Set options associated with elevation ranges.
 - Speed Options: Set options associated with speed ranges.
 - Frames Per Second: Show and set frame generation speed.
 - Coordinates: Choose xy positional reporting system.
 - Units: Choose elevation and speed reporting unit.
 - Render Quality: Change rendering quality (i.e. blocky, fitted, smooth).
 - Render Mode: Change rendering mode (i.e. normal or 3D).

 See Also: {..|..|}Elevation Options,
       {..|..|}Speed Options,
       {..|..|}Frames Per Second,
           {..|..|}Coordinates,
       {..|..|}Units,
       {..|..|}Rendering Quality,
       {..|..|}Render Mode

1    Rendering Window
@keyword{Rendering Window}{Mouse}

 In the FLY! Rendering Window, the mouse buttons can be used to
 turn, pause/run, and change elevation quickly and naturally. The
 following button assignments are made:

 -left button  (For MacOS Systems, just click on the mouse button)

 Turn. Changes the direction of viewing (and of movement).
 The new direction faces the position clicked on in the rendered image.

 -middle button (or ctrl-left button)
  (For MacOS Systems, hold down the "up" arrow key while pressing the
   mouse button)

 Run/pause. Toggles between pause (stop) and run (go). This is
 referred to as user free flight mode.

 -right button.
  (For MacOS Systems, hold down the "down" arrow key while pressing
   the mouse button)

 Change Elevation. Changes elevation proportional to the
 position of the mouse cursor in the vertical direction. Clicking
 near the top of the window changes to a high elevation, near the
 bottom to a low elevation. The elevation set is related to the
 elevation range as set in the elevation options.

 See Also: {..|}User Free Flight, {..|}Elevation Options

1    Load Terrain from Elevation Only
@keyword{Load}{Terrain}

 This option allows the user to create a terrain using elevation data
 only. The terrain will be shaded using a technique known as shaded
 relief. A directional light source is specified and a computation is
 made for each pixel in the imagery to determine how bright that pixel
 would be. Typically, this light source could be considered to be the
 sun.

 Shade in Full Colour

 This first calculation only gives a brightness value. To compute full
 colour, a colour space transformation is performed. Given an
 intensity, hue and saturation (IHS), values in this colour space can
 be transformed to red, green and blue intensity values (RGB). The
 intensity used is the brightness that was computed from shaded relief.
 The hue is proportional to the height of the pixel and the saturation
 is fixed at 50%.

 Shade as Grey Levels

 The brightness level computed from shaded relief is used directly as
 the grey level intensity of the terrain.

 Elevation Information

 The 'Select Elevation File...' pops up a channel selection panel for
 the user to choose a file and a channel within that file to use as the
 elevation. The chosen information will be reflected in the 'Elevation
 Data'. If a file has not already been previously selected, a file
 selection panel will be displayed to allow the user to choose an image
 database file.

 The 'Elevation Smoothing' option menu allows the user to smooth the
 elevation somewhat to reduce the impact of distinct steps in the
 elevation model on shaded relief calculations.

@verbatim
    None        no smoothing performed
    Slight      5 x 5 Gaussian filter with standard deviation 2
    Medium      5 x 5 Gaussian filter with standard deviation 3
    Extreme     5 x 5 Gaussian filter with standard deviation 4
@end

 Colour Information

 A 'Colour Enhancement' can be specified to enhance each colour channel
 of the terrain. Valid values are 'Linear' for linear enhancement,
 'Root' for square root enhancement or 'Equalize' for histogram
 equalization.

 The 'Sun Position for Shaded Relief' is used to specify where to place
 the light source. If a ray is defined by the center (in a pixel and
 line sense) of the terrain and the position of the sun in the sky,
 then the 'inclination' angle is the angle between that ray and the
 plane of the terrain. The 'direction' determines the direction (from
 an overhead point of view) that the sun is shining from.

 The 'Default' button sets the angles to their default values of 45 for
 inclination and 0 for direction. The 'None' button places the sun
 directly overhead at 90 degrees inclination and 0 for direction.

 Database Information

 The 'Pixel Size' is used to specify how large each pixel is on the
 ground. A database pixel is assumed to be square so this number gives
 a measure of how many meters each side of this square is. The default
 value is 1.00 m although for PCIDSK files, if this value is specified
 in the file, it will be read and filled in automatically.

 The 'Pixel Height' is used to specify how tall one unit elevation data
 is. For example, if the digital elevation model value is 1000, and the
 pixel height is 1.00 m, then the real elevation is computed to be 1000 m.
 Similarly, if the pixel height is 10 m, then the real elevation
 would be 10000 m. The default value is 1.00 m.

 The 'Terrain X Size' and 'Terrain Y Size' is used to determine the size that
 the resultant terrain will be. The elevation data region need not be the
 same size as the created terrain. They don't even have to be of the same
 ratio. The data will be scaled up or down accordingly. When an elevation
 file is selected, these fields are automatically updated to the size
 of the elevation data but they can be overwritten manually.

1    Load Terrain from Elevation and Colour
@keyword{Load}{Terrain}

 This option allows the user to create a terrain using elevation data
 and colour information from an image database file. For full colour,
 three colour channels are required, one each for red, green and blue.
 For grey level, only one channel is required to specify the brightness.

 Elevation Information

 The 'Select Elevation File...' pops up a channel selection panel for
 the user to choose a file and a channel within that file to use as the
 elevation. The chosen information will be reflected in the 'Elevation
 Data'. If a file has not already been previously selected, a file
 selection panel will be displayed to allow the user to choose an image
 database file.

 The 'Elevation Smoothing' option menu allows the user to smooth the
 elevation somewhat to reduce the impact of distinct steps in the
 elevation model.

@verbatim
     None        no smoothing performed
     Slight      5 x 5 Gaussian filter with standard deviation 2
     Medium      5 x 5 Gaussian filter with standard deviation 3
     Extreme     5 x 5 Gaussian filter with standard deviation 4
@end

 Colour Information

 The 'Select Colour File...' pops up a channel selection panel for the
 user to choose a file and a channel within that file to use for
 retrieving colour. The chosen information will be reflected in the
 Channel Data boxes. If a file has not already been previously
 selected, a file selection panel will be displayed to allow the user
 to choose an image database file.

 A 'Colour Enhancement' can be specified to enhance each colour channel
 of the terrain. Valid values are 'Linear' for linear enhancement,
 'Root' for square root enhancement or 'Equalize' for histogram
 equalization.

 Database Information

 The 'Pixel Size' is used to specify how large each pixel is on the
 ground. A database pixel is assumed to be square so this number gives
 a measure of how many meters each side of this square is. The default
 value is 1.00 m although for PCIDSK files, if this value is specified
 in the file, it will be read and filled in automatically.

 The 'Pixel Height' is used to specify how tall one unit elevation data
 is. For example, if the digital elevation model value is 1000, and the
 pixel height is 1.00 m, then the real elevation is computed to be 1000 m.
 Similarly, if the pixel height is 10 m, then the real elevation
 would be 10000 m. The default value is 1.00 m.

 The 'Terrain X Size' and 'Terrain Y Size' is used to determine the size that
 the resultant terrain will be. The elevation data region need not be the
 same size as the created terrain. They don't even have to be of the same
 ratio. The data will be scaled up or down accordingly. When an elevation
 file is selected, these fields are automatically updated to the size
 of the elevation data but they can be overwritten manually.

2    Channel Selector

 The Channel Selection Panel allows the user to select one or more
 channels to be used to define the terrain. This panel only allows
 selection of channels and does not cause any loading to take place
 explicitly. A subwindow of data may also be selected.

 The 'Database Channels' section of the panel alows the user to select
 the image channels by clicking on them. The database channels are
 found in the scrollable list with a description of the source data
 type and the descriptor from the file.

 Beneath the scrollable list is a series of channel mapping pairs. On
 the left of each pair is the type of channel and on the right is a
 blank field into which a database channel number can be placed. When
 one of the text fields contains a number, it indicates that the corresponding
 channel type will use this channel number from this file for its information.

 Beneath the channel mapping pairs are 'Clear' and 'Default' buttons.
 Pressing the 'Clear' button erases the current channel map while
 pressing the 'Default' button establishes a default channel mapping.
 This default is usually the first n channels in a database where n is
 the number of channels required to be selected.

 The 'Database Window Selection' allows the user to specify a subwindow
 of the database to load. By default, the entire image is specified.

 At the bottom of the panel is the action button area. 'Select & Close'
 selects the channels currently chosen by showing that information in
 the main loading panel and pops the channel selection panel down. The
 'Select' and 'Close' buttons performs the selecting and closing
 operations described in 'Select & Close' except separately. The 'New
 File' button can be used to select a different file from the currently
 selected one.

3    Raw File Definition

 When an unrecognizable file is selected, the user is given the option
 of defining it as a raw imagery file. This panel is used to define the
 format of this raw file.

 The 'Header Bytes' field specifies how many bytes at the beginning of
 the file represent header information to be ignored. The default value
 is 0 indicating that the imagery data starts right at the beginning of
 the file.

 The 'Channels' field indicates the number of channels or planes of
 image data that are stored in the file. This value defaults to 1.

 The 'Pixels' and 'Lines' field defines the X (pixel) and Y (line) size
 of the image in the raw file. These should be the full size of the
 image in the file, even if the user only wishes to load a subwindow of
 the whole file.

 The 'Data Interleaving' option menu indicates how multiple channels of
 image data are interleaved. This field is not really applicable for 1
 channel image files. Possible choices are as follows:

 -Pixel: The channels are pixel interleaved. For instance, for a
  three channel file, the values in the file would be 123123123...,
  with the channel values for a given pixel located together.

 -Line: The channels are line interleved. The data for line 1 of the
  first channel occurs first, followed by the data for line 1 of the
  second channel and line 1 of the third channel. Next is line 2 of
  the first channel, etc. For instance, for a three channel file,
  the values in the file would be
  (line 1)111...222...333(line2)111...222...333...

 -Band: The channels are band sequential. All the data for the
  entire first channel would be first, followed by all the data for
  the second channel, etc.

 The 'Data Type' field is used to define the size and meaning of the
 data read for each pixel.

 -8 bit: The data for each channel of each pixel are 8 bit,
  unsigned. Values range from 0 to 255.

 -16 bit Unsigned: The data for each channel of each pixel are 16
  bit, unsigned. Values range from 0 to 65535, and are two bytes each.

 -16 bit Signed: The data for each channel of each pixel are 16 bit,
  signed. Values range from -32768 to 32767, and are two bytes each.

 -32 bit Real: The data for each channel of each pixel are 32 bit
  IEEE floating point numbers. Each value is 4 bytes long.

1    Save Rendering
@keyword{Save}

 Terrain renderings can be saved to an image file on disk in a variety
 of formats such as: PCIDSK, Tiff, and JPEG. Once saved to disk,
 rendered scenes can be imported or printed by other software packages.

 The 'Format' option menu specifies all of the formats that are currently
 supported.

  See Also: {GDB|Sup|}PCIDSK,
            {GDB|Sup|}ERDAS Imagine,
            {GDB|Sup|Joint}JPEG,
            {GDB|Sup|}Raw Image Format,
            {GDB|Sup|}TIFF,
            {GDB|Sup|}X Window Dump,
            {GDB|Sup|}Sun Raster,
            {GDB|Sup|}Laser-Scan

1    Flight Panel
@keyword{Flight}

 The flight panel is used to create flightpaths. A flightpath is composed
 of several nodes. The path is generated in such a way that the path
 must travel through the nodes. When the viewer passes through a node,
 the flying direction is the movement direction when that node was
 recorded. The node stores the position, direction, and speed parameters
 as well as some of the perspective parameters like pitch, view cone
 and zoom level.

 The path starts at the first node, travels through all intermediate nodes
 and ends at the last node. The path is composed of a series of bezier spline
 made to fit through the nodes.

 The top of the panel shows the total length of the current flight path.
 The panel features a list below this, showing the current nodes. Below
 this is a series of buttons used to edit nodes: 'Assign', 'Insert', 'Add',
 and 'Delete'. A playback section contains VCR type controls to play
 the flight back, both forwards and backwards. There is also a special
 action button to 'Generate Movie Loop's. This button only appears in the
 unix versions of FLY! since the only supported movie format is
 the Parallax movie loop format. To play back this format, a Parallax
 video card is required.

 When there are no nodes in the path, it is only possible to add nodes.
 This is done with the 'Add' button. Pressing the add button will
 add a node to the end of the current list. The node will be composed
 of the current rendering parameters (that are always used to produce the
 image in the rendering window). The selected node is the one currently
 highlighted in the node list. The 'Update' button changes the selected
 node to the current rendering parameters. The 'Insert' button inserts
 a node behind the current node and shifts everything else down one. The
 newly highlighted node will be the one just inserted. The 'Delete' button
 will remove the current node from the list and shift everything up one.
 The 'Clear' button will remove all the nodes in the list.

 The node list shows a list of nodes. The first number is the node number,
 followed by the x, y position in pixels, lines and the elevation. Choosing
 a node from the list will change the currently selected node. This will
 change the rendering parameters to those stored with the selected node.

 The playback area allows the flight to be played back in the rendering
 window. There are five VCR type controls that can be used. They are:

 - <<: fast backward. Flight is played back 10x faster in the reverse
   direction.

 - <: backward. Flight is played back in the reverse direction.

 - []: stop. Stops the playback.

 - >: forward. Flight is played back in the forward direction at a regular
   speed.

 - >>: fast forward: Flight is played back 10x faster in the forward
   direction.

 Flight playback occurs from the current position along the path. Note
 that selecting a node in the list will change the path position.
 While a flight is being is played back, all of the conventional methods
 of changing the scene parameters (i.e. clicking in the rendering window,
 the main control panel, etc.) are disabled. As well, the panel cannot
 be popped down during playback. While FLY! is in user free flight mode,
 playback can not take place.

 The continuous playback mode can be used to cause the path to be flown over
 repeatedly. Otherwise, playback stops when the viewer reaches the beginning
 or end of the path.

 When there are no nodes in the flight path, playback is not allowed.

2    Movie Loop
@keyword{Movie}

 The 'Generate Movie Loop' button becomes activated, and therefore usable,
 only after a flight has been created. When this option is selected, a
 dialog is displayed showing the movie characteristics.

 It is possible to choose from several movie formats. Each has its own
 specific options.

 There are three courses of action from this dialog. The 'Ok' button
 creates the movie file. Pressing 'Cancel' pops the dialog down and 'Help'
 displays this help text.

 Once the 'Ok' button is pressed, the movie will be generated.

 The movie always starts at the beginning of the path and continues until the
 last node is reached. As the movie is generated, the progress is shown
 in the main panel.

 Regardless of the display type (i.e. 8 bit, Black/White, 24 bit),
 the scenes being added to the movie are always rendered in 24 bit color mode.
 The images will be displayed in the render window if the display type
 suppports 24 bit color, otherwise the render window is left blank.

 Once the process begins, it cannot be stopped. The interface will become
 insensitive to disable the user from altering the rendering parameters.

3    Sequential Movie Formats

 It is possible to write out the movie as a series of individual images.
 TIFF and JPEG format files are available.

 The base filename is composed of 3 characters. The files will be written
 out with the filename bbbnnnnn.ext where "b" represents the 3 character
 base, "n" represents the frame number and "ext" is dependent on the file
 type.

 For example, if TIFF format is chosen and the base filename is FLY,
 the files written out will be FLY00000.tif, FLY00001.tif, etc.

3    Parallax Movie Loops
@keyword{Parallax}

 Playback flights can be written to the Parallax JPEG movie format by
 using the 'Generate Movie Loop' button from the flight panel and selecting
 the Parallax movie format.

  Rendering Size      : This value depends on the current size of
                        the rendering window.
  Filename            : The movieloop filename
  Frames per second   : Specify frame speed.
  Quantization Factor : This value is fixed to 50. This means that
                        the default quantization tables given in the
                        JPEG standard is used.

 For an image of size 320x240, a JPEG frame will require approximately
 10K of disk space. At 15 frames a second, this comes out to 150K per
 second, or 9M per minute. Disk space is not checked before writing, so
 it is up to the user to make sure that there is sufficient space to
 create the movie.

 The concept of Frames Per Second is very important to the generation
 of a movieloop. When determining the flight path positions, FLY! uses
 both the speed parameter as well as the frames per second of the
 application. The positional changes are calculated such that after one
 full hour, the point of view has moved on the terrain the distance indicated
 by the speed.

 Usually, the real-time rendering speed is used to determine how many
 frames are being generated per second. For example, if it takes .2 seconds
 to generate a frame, then there are 5 frames being generated every second.
 This is fine when using user free flight, but when generating movies,
 the playback speed is often fixed.

 The rate at which frames are rendered will typically be slower
 than the playback speed of the loop and therefore, the viewer will
 seem to move faster than the speed indicated on the control panel when
 the movie is played. For example, if the frames are rendered at 3 fps,
 and the speed on the control panel is 500 km/h, played back at 15 fps,
 the viewer will seem to move at a rate of 2500 km/h. If the movie is
 played back at 15 FPS, the the frames of the movie should be generated at
 a rate of 15 FPS.

 This can be accomplished by using the Frames Per Second panel from the
 'Options' menu. This panel can be used to tell FLY! that the FPS is
 user defined and the frames should be generated according to some
 virtual FPS instead of what is really happening on your computer.

 Note that the 'Frames Per Second' field on the panel is only what is written
 to the Parallax movie file. It is not the FPS that FLY! uses to determine
 how to generate scenes. That FPS is set using the Frames Per Second panel
 found from the 'Options' menu item.

 Other Notes:

 None of the Audio elements of the movieloop are used. All fields
 pertaining to audio tracks are left blank.

 The movie file is written out with version set to 2.

 Once the movie creation processed is started, it is wise not to resize the
 rendering window.

 See Also: {fly|}Frames Per Second, {fly|}Render Mode

2    Flight Files
@keyword{flight}

 The flight files are saved in the following format:

@verbatim
 ; FLY! Flight Path
 Version: FLY! V6.0
 Dimension: [terrain x size] [terrain y size]
 Node: [x in pixels] [y in lines] [height in elevation units]
       [difference in move/view dir (i.e. view dir = move dir + diff)]
       [move dir] [view cone] [zoom factor] [pitch angle] [speed]
 ...
@end

 Note that the node parameters are all contained on the same line but
 is broken up in the above description for formatting purposes.

2    Loading/Saving
@keyword{flight}

 To choose a flight path file, simply use the file selector to choose
 the desired file.

 Each flight path is created on a terrain of a specific size. Loading a
 flight path on a terrain whose size is different than that of the flight path
 is not allowed.

1    Change Position/Speed/Direction
@keyword{position}{speed}{direction}

 This panel is activated via the 'Position, Speed, Direction' option in the
 'Edit' menu from the main menubar. It allows the user to modify the
 the viewing position as well as the speed and movement direction.

 This panel allows the user to explicitly enter values for the viewer's
 position, direction and speed. Note that these parameters can also be
 set with the Control Panel. This panel is useful if exact positioning
 is required.

1    Change Render Size
@keyword{size}

 This panel is activated via the 'Render Size...' option in the 'Edit' menu
 from the main menubar. It allows the user to specify the size of the
 rendering window in pixels and lines. Please note that this window can
 also be resized by dragging out one of its corners.

 The 'Frame X Size' field specifies the x size for the frame in pixels.
 The 'Frame Y Size' field specifies the y size for the frame in lines.

 Common sizes for rendering windows are 320 by 240 or 640 by 480. The
 minimum is 64 by 64. The maximum is 1024 by 768.

1    Change Perspective
@keyword{perspective}

 This panel is activated via the 'Perspective...' option in the 'Edit' menu
 from the main menubar. It allows the user to modify the perspective
 parameters of the rendered image.

 The 'Height Magnification' field allows the effects of elevation to be
 exaggerated. The default setting is 1.0. Values can vary from 0 to
 3.0. A value of 0 has the effect of removing elevation.

 The 'Horizon Tilt' field allows the horizon position to be varied in
 degrees. Values can be varied from 0 to 60. The default is 25 degrees.

 The 'Pixel Zoom' field controls the size of the foreground pixels at low
 elevations. It can vary from 1 to 100 percent. The default is 100
 percent. The maximum size of foreground pixels is automatically
 determined by FLY! and is not under user control.

 The 'View Cone' field controls the view cone used in the rendered image.
 This can vary between 30 and 120 degrees. The default is 60 degrees.
 Larger values for view cone tend to exaggerate the effects of
 perspective.

1    Change 3D Parameters
@keyword{3D}

 This panel is activated via the '3D...' option in the 'Edit' menu from
 the main menubar. It allows the user to modify the parameters which
 control 3-D viewing.

 The 'Base Line' field specifies how far apart the left/right images are.
 Values can be from 1 to 30 pixels. The default is 4 pixels.

 The 'Focal Length' field specifies the focusing point in pixels. Values
 can vary from 32 to 512 pixels. The default is 64 pixels.

 Altering these values can enhance the 3-D effect (and possibly give
 you a headache).

 See Also: {..|}Render mode, {..|}3D Images

1    Elevation Options
@keyword{elevation}

 This panel controls options associated with setting the viewer elevation.

 The 'Elevation Minimum' and 'Elevation Maximum' fields determine the
 range of elevation values used by the elevation slider on the control
 panel. The maximum must be greater than the minimum. This range is also
 used for setting the elevation from the rendering window. The entire
 height of the rendering window can be thought of like the elevation slider
 with the bottom of the window representing the elevation minimum and
 the top of the window representing the elevation maximum.

 The 'Scaling' determines the type of scale used to translate the range
 value to an actual elevation. For example, a square scale will cause
 the elevation value to be proportional to the square of the slider value.

 The 'Mode' dictates how the elevation value is actaully translated into
 the viewer's elevation.

 - In 'No collision' mode, the rendering should never occur "inside"
   the terrain. This means that the rendering height is never allowed
   to occur below the land elevation. For example, if the land elevation
   is 218 m and the elevation is set to 250 m, then the viewer is placed
   at 250 m. However, if the elevation is set to 200 m, the value is
   clipped and the viewer is placed at 218 m. The land elevation is given
   on the Control Panel.

 - In 'Relative' mode, the view elevation is the land elevation + the
   value of the elevation scale. For example, with the elevation scale all
   the way to the left, the rendering height would be equal to the
   land elevation + the elevation range minimum. With the elevation all the
   way to the right, the rendering height should be the land elevation + the
   elevation range maximum.

 - In 'Absolute' mode, the elevation scale value is used directly as
   the rendering height. If the elevation is below the land elevation,
   the rendering looks like a bunch of vertical strips (because the
   viewer is inside the terrain).

 See Also: {..|}Control Panel, {..|}Rendering Window

1    Speed Options
@keyword{speed}

 This panel controls options associated with setting the viewer speed.

 The 'Speed Maximum' field determines the range of speed values used
 by the speed slider on the control panel. The minimum is always 0.

 The 'Scaling' determines the type of scale used to translate the range
 value to an actual speed. For example, a square scale will cause
 the speed value to be proportional to the square of the slider value.

 See Also: {..|}Control Panel

1    Frames Per Second
@keyword{FPS}{frames per second}

 When continuous frames are being generated (as in user free flight mode
 or flight playback), there are two methods to determine how far the viewer
 has moved between frames.

 Choosing the 'Based on rendering time' option means that the viewer will
 move forward at a rate based on the speed chosen and the time it takes to
 render the frame. With this method, after one hour of actual time, the
 viewer will have moved the distance specified by the speed. (i.e. if
 moving at 5 km/h, after one hour, viewer will have moved an equivalent
 of 5 km on the terrain). When this mode is chosen, the current real FPS
 is shown.

 Choosing the 'User defined' option means that the viewer will move
 at a rate as if that many frames per second were being generated.

 Whatever option is chosen, the distance between frames for the current
 speed is shown. For example, at a rate of 15 frames per second,
 a speed of 500 km/h will result in an distance movement of 9.26 m. Thus,
 the viewer will move 9.26 m/frame x 15 frames/second x 3600 seconds/hr =
 approx. 500 km (Note that the 9.26 is a rounded figure).

 See Also: {..|}User Free Flight

1    Coordinates
@keyword{coordinates}

 The coordinates are used to choose a reporting system for position.
 The choices are:

 - Display: Position reported in pixels and lines in the loaded terrain.
 - Geocoded: Position reported in geocoded units as eastings and northings.
 - Geographic: Position reported in geographic units as longitude and latitude.

1    Units
@keyword{units}

 The units are used to choose a reporting unit for distance and speed values.
 The choices are:

 - Metric: distance reported in m, speed in km per hour.
 - Imperial: distance reported in ft, speed in miles per hour.

1    Rendering Quality
@keyword{quality}

 The render quality is selectable from the 'Options' topic from the menubar.
 It allows the user to specify the quality of the images being rendered.
 Three options are available: blocky, fitted and smooth.

 In blocky rendering mode, each pixel appears as a box with pronounced
 steps between pixels. This is the default rendering mode and the
 fastest.

 In fitted rendering mode, the edges of the pixels are interpolated so
 they fit together without any step effects. This rendering mode is
 about 75% of the speed of the blocky rendering mode.

 In smooth rendering mode, the edges of the pixels are interpolated so
 they fit together without any step effects and the colours of the
 pixels are smoothly blended. This rendering mode is 30% of the speed
 of the blocky rendering mode.

1    Render Mode
@keyword{mode}

 There are two choices of rendering mode:

 - Normal: This is the regular rendering mode.

 - Anaglyph 3D: This is a special mode of rendering where the left view
   is rendered in red and the right view in blue. These two views are
   combined to form a stereo image. Anaglyph glasses (with red and
   blue tinted lenses) are required to view these images properly.

 On SGI workstations, two additional rendering modes are available:

 - Stereoglasses: This puts FLY! into color stereo mode. FLY! will use
   the entire screen in this mode. Special hardware liquid crystal
   stereoglasses are required to view in this mode.

 - Stereoglasses (expanded): In this mode, the stereo view is expanded
   in both the vertical and horizontal directions to produce an image
   4x as large as the regular stereoglasses mode.

 While in stereoglasses mode, the flight can be played back by pressing
 the spacebar. Pressing the spacebar again while the flight is being played
 back will terminate the playback. Pressing any other key will bring the
 user back to normal mode.

 See Also: {..|}3D Images

1    Control Panel
@keyword{control}{parameters}

 This panel is composed of several different areas, each used to set and
 report parameters relating to the viewer position, direction, elevation and
 speed.

 The position area is a square area that is mapped into the terrain. This
 square is scaled to the entire terrain area, regardless of the terrain's
 real aspect ratio. So, each corner of the square represents the corresponding
 corner of the terrain.

 A left click in the position area will place the viewer at that location
 on the terrain. A right click will change the move and viewing directions
 to point to that location. If the moving and viewing directions are
 already different, then only the move direction changes. A middle click
 changes the viewing direction only.

 The direction area is a graphical indicator of the current viewer movement
 direction as well as what direction the viewer is facing. It is possible
 to move in one direction while looking at another. The two need not be
 the same. The movement direction is indicated by the longer black line while
 the view direction is indicated by the shorter red line. The current rendering
 is always created from the view direction while forward movement caused
 by user free flight uses the movement direction.

 A left click in the direction area will change the move and view directions.
 A right click will change the view direction only. A middle click will change
 the move direction only.

 There is a text information area to the right of the direction area which
 reports the current position, speed and directions. This information always
 reflects the current rendering. The coordinates and units used for
 reporting can be set from the 'Coordinates' and 'Units' menus from
 the 'Options' menu.

 The elevation slider is used to change the elevation. The range of this
 slider is determined by the 'Elevation Range' panel, accessible from
 the 'Options' menu. Although the slider will indicate an elevation value,
 how it is interpreted depends on the elevation mode. Refer to the
 'Elevation Options' topic for more details.

 The speed slider is used to change the speed. The range of this
 slider is determined by the 'Speed Range' panel, accessible from
 the 'Options' menu.

 See Also: {..|}Coordinates, {..|}Units, {..|}Elevation Options,
       {..|}Speed Options

1    User Free Flight
@keyword{flight}

 User free flight is a special FLY! mode in which the viewer is continuously
 moving forward. The forward direction is determined by the movement
 direction. While in this mode, all of the usual methods of moving the
 viewer and the rendering parameters still work. For example, interactive
 movement can be achieved by clicking in the rendering window. A left
 click will change the flying direction. A right click will change the
 elevation. A middle click will put in and out of the free flight mode.

 When the viewer flies off one side of the terrain, they reappear on the
 other side. The distance at which the viewer advances is based on
 the number of frames being generated and the flying speed. It is computed
 such that if the speed is 50 km/h, after one hour the viewer would
 have traveled 50 km on the terrain's surface.

 While in this mode, file interactions such as loading and saving are not
 allowed.

 See Also: {..|}Rendering Window, {..|}Frames Per Second

1    Nadir View
@keyword{nadir}

 This panel is used to show the overhead (or nadir) view of the terrain.
 This window is approximately 512 pixels by 512 lines in size and shows
 a decimated overview of the data if the loaded imagery is larger than
 this size. The window dimensions will vary to maintain a 1:1 aspect ratio.

 The current position is shown in the nadir view as a black and white
 marker. The white portion of the marker is a cross shape. The black
 portion forms an X. Hopefully, this marker will be visible in both
 light and dark regions. The extension on the marker indicates the
 current movement direction.

 A left click in the nadir view will place the viewer at that location
 on the terrain. A right click will change the move and viewing directions
 to point to that location. If the moving and viewing directions are
 already different, then only the move direction changes. A middle click
 changes the viewing direction only.

 There are two buttons at the top of the panel. The first button pops
 up a panel to set some options for the nadir window. The second button
 allows the user to toggle between views of the terrain imagery or elevation.

2    Nadir Options

 This panel allows the following options to be set:

 - Show Path: When this is on, the flight path is drawn in the nadir view.
   When it is off, the flight is not redrawn which should give slightly
   faster redraws of the nadir view.

 - Show Node Numbering: When this is on, each node in the path is
   shown with its node number. It can be turned off if the numbering
   is cluttering the nadir view.

 - Path Colour: Colour to draw the flight path in. It can be changed with
   the Edit... button.

 - Highlight Colour: Colour to draw the currently highlighted node in. It can
   be changed with the Edit... button.

 - Path Resolution: The splined flight path is drawn using line segments.
   This value determines how many total line segments to use for drawing
   the path. A higher number means that the path should look smoother since
   more lines are used to draw a curve. However, the more lines to draw,
   the longer it will take to redraw. This can be an issue when editing
   that path. Note that this does not affect the actual flight path,
   which is always a smooth bezier curve. This option only affects how
   it is draw on the screen.

 See Also: {works|modify col}Color Mixer

1    Memory Usage and Speed Hints
@keyword{Memory}{Speed}

 FLY! is a memory intensive application. The following chart shows the
 RAM memory required for various input data sizes:

@verbatim
    1024 x 1024       7 Mbytes
    1536 x 1536      14 Mbytes
    2048 x 2048      24 Mbytes
    4096 x 4096      88 Mbytes
@end

 Add 5 to 8 Mbytes on top of this for the operating system and user interface.

 For example, if your workstation has 32 Mbytes of RAM, a 1536 x 1536
 database should run well. A 2048 x 2048 database, which would also
 work, may have very poor performance since RAM memory would be
 overloaded and the workstation would spend most of its time swapping
 memory to and from disk.

 To achieve maximum performance, it is best not to run any other
 applications while FLY! is active.

1    3D Images
@keyword{3D}

 FLY! has the ability to render frames which give an appearance of true
 3D depth.

 The 3-D effect is produced by generating slightly different left and
 right views for the left and the right eyes. The left view is
 rendered in blue, the right view is rendered in red, both views are
 merged. The user must wear anaglyph glasses (i.e. glasses with a blue
 lense for the left eye, red for right) when viewing the merged image.
 The blue lense filters the left image to the left eye and the red the
 right image to the right eye. The brain then integrates the resulting
 two images to be 3D.

 See Also: {..|}Render Mode, {..|}Change 3D

1    Spaceball (Only available on SGI platforms)

 If a spaceball is attached to the workstation, it is possible to use
 it to maneuver. Its usage is fairly intuitive. Simply push the
 spaceball in the direction of movement: forward, backward, left, right,
 up or down. Twisting the ball will also change the view/movement
 direction as well as the horizontal tilt.