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This is vamos.info, produced by makeinfo version 4.13 from vamos.texi.
INFO-DIR-SECTION Applications
START-INFO-DIR-ENTRY
* Vamos: (vamos). An automotive simulator
END-INFO-DIR-ENTRY
Vamos Automotive Simulator, by Sam Varner.
This file documents the Vamos libraries and application.
Copyright 2001-2012 Sam Varner
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1 or
any later version published by the Free Software Foundation; with no
Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
Texts. A copy of the license is included in the section entitled "GNU
Free Documentation License".
Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.
Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that this permission notice may be stated in a
translation approved by the Free Software Foundation.
File: vamos.info, Node: Top, Next: Let's Go, Prev: (dir), Up: (dir)
Vamos Automotive Simulator
**************************
Sam Varner <snick-a-doo@comcast.net>
Vamos is an automotive simulation framework with an emphasis on
thorough physical modeling and good C++ design. Vamos includes a
real-time, first-person, 3D driving application.
This file documents Vamos version 0.7.0.
* Menu:
* Let's Go:: Getting on the road.
* Controls:: Keyboard and joystick settings.
* Dashboard:: On-screen information.
* Cars:: Choosing and creating cars.
* Tracks:: Choosing and creating tracks.
* Worlds:: Specifying environments.
* Units:: A note about units of measure.
* Code Reference:: The inner workings.
* Building Vamos:: Downloading and compiling the program.
* Copying:: The GNU Free Documentation License.
* Concept Index:: An item for each concept.
File: vamos.info, Node: Let's Go, Next: Controls, Prev: Top, Up: Top
1 Let's Go
**********
The `vamos' application lets you experience the simulation first hand.
Its main purpose is to be a test bed for the libraries. It is not
intended to be a polished end-user application. However, you can drive
on a number of tracks and try to beat your best time. Or you can just
have fun driving on, and over, the ragged edge.
1.1 Getting Started
===================
When you start the application with no arguments you will be looking out
over the hood of your car, down the front straight of a simple,
fictitious circuit. Give the car a little gas and shift into first by
pressing and releasing the first joystick button. The clutch is engaged
gradually, so you will need to increase the throttle to keep the engine
revs up. If you stall, shift back to neutral (second button) and press
the <s> key to restart the engine. *Note Controls::.
Once you get going you will need to shift into second. When you
press the button to shift, the clutch is disengaged. It is re-engaged
when you release the button. You will need to back off the throttle
when the clutch is disengaged in order to make your shifts smooth. As
with shifting to first gear, the clutch is engaged gradually, although
much more quickly.
The first turn on the circuit is a sharp left-hander at the top of a
hill. This is a good place to practice sliding the car through a turn.
You will probably hear the tires slide as you enter the turn. Don't
worry, the tires actually have _more_ grip when they're sliding a
little. However, you do lose some directional stability. So you point
the nose a little toward the center of the turn and use the throttle to
hold the car in the turn. If you slide the car more than a little, you
will lose grip and probably find yourself in the gravel.
When driving on the edge, the throttle and brake do as much as the
steering wheel to control the trajectory of the car. In general,
accelerating tends to straighten out the car and braking tends to turn
the car more. To demonstrate this, try backing off the throttle midway
through a turn. You'll find that the back end steps out a little
causing the car to turn in.
1.2 Robot Cars
==============
You can race against computer-controlled opponents. Use the `o' option
with a numeric argument to race against other cars. Use the `d' if you
just want to watch.
File: vamos.info, Node: Controls, Next: Dashboard, Prev: Let's Go, Up: Top
1.3 Controls
============
The car can be driven with a joystick, keys, or even a mouse. A
joystick is highly recommended.
Keys, buttons, and joystick axes are mapped to functions in an XML
file in the data directory (usually `/usr/local/share/vamos/controls').
By default the file `default-controls' is used. You can specify a
different file with the `-a' or `--controls=' options. The default
control bindings are as follows:
Key Stick Action
<Up>* Forward Throttle.
<Down>* Backward Brake.
<Left>* Left Turn left.
<Right>* Right Turn right.
<Insert>* Button-1* Shift up.
<Delete>* Button-2* Shift down.
<Home>* Button-3* Clutch.
<a> Place the car back at the starting line.
<r> Place the car back on the road.
<s> Start the engine after a stall.
<f> Fill the fuel tank.
<c> Reload the car definition file.
<t> Reload the track definition file.
<p> Pause the application.
<q> Exit the application.
<F9> Cycle through the views.
The `*' symbol indicates that the action is performed gradually after
the key or button is pressed.
When shifting, pressing the key or button causes the clutch to be
disengaged before the new gear is selected. Releasing the button
releases the clutch. The clutch is engaged slowly when shifting from
neutral, and more quickly for other gears. The clutch is always
disengaged quickly.
1.4 Control File Format
=======================
Here's the format of a controls file.
<controls name="Name">
<!-- Key Binding -->
<bind>
<function>function name</function>
<key>k</key>[<up|down/>]
[<time>t</time>]
</bind>
<!-- Button Binding -->
<bind>
<function>function name</function>
<button>b</button>[<up|down/>]
</bind>
<!-- Axis Binding -->
<bind>
<function>function name</function>
<axis>a</axis>
[<factor>f</factor>]
[<offset>o</offset>]
[<minimum>m</minimum>]
</bind>
</controls>
The `function' tag gives the name of the function to bind. Any
member funciton of Gl_Car_World that takes two double arguments and
returns a bool can be bound. The case of the name inside the
`function' tag must match the actual function's name, and underscores
must be replaced with single spaces.
The `down' tag binds the function to a key (or button) press; `up'
binds it to a key release. If neither is specified, the function is
bound to a key press.
The `time' tag sets how long it takes for setting to be ramped up to
its target value. It is used for controling continuous values, like
throttle, from the keyboard. The default time is 0.
For joystick axes, vaules range from -1 to 1. This number is
multiplied by the value in the `factor' tag and then the value in the
`offset' tag is added. The result is clipped at `minimum'. The
defaults are 1, 0, 0, respectively.
1.4.1 Bindable Functions
------------------------
These are the functions that can be bound to controls.
`pause'
Pause the simulation.
`quit'
Quit the program.
`cycle view'
Change the point-of-view from car to trackside to overhead.
`read car'
Read the car definition file.
`read track'
Read the track definition file.
`read world'
Read the world definition file.
`restart car'
Put the car at the starting line.
`reset car'
Put the car back on the track.
`fill tank'
Fill the car's gas tank.
`gas'
Operate the throttle.
`brake'
Operate the brakes.
`steer'
`steer left'
`steer right'
Operate the steering wheel. The 'steer left' and 'steer right'
functions are useful for binding to keys.
`shift up'
`shift down'
Select an adjacent gear, except when in neutral.
`shift up disengage'
`shift down disengage'
Select an adjacent gear and operate the clutch, except when in
neutral.
`initial shift up'
`initial shift down'
Select an adjacent gear when in neutral.
`initial shift up disengage'
`initial shift down disengage'
Select an adjacent gear and operate the clutch when in neutral.
`clutch'
Operate the clutch.
`engage clutch'
`disengage clutch'
Operate the clutch, except when in neutral
`initial engage clutch'
`initial disengage clutch'
Operate the clutch when in neutral
A function can be bound to more than one control. However, when the
simulation is running, the joystick is read after the keys. If, for
example, you bind the throttle to the up arrow key and to a joystick
axis, the joystick (if present) will override the keyboard.
Similarly, more than one function can be bound to a control. Each
function is called in turn until one of them returns true.
For shifting, you will likely bind two functions to each shifting
control, one for shifting from neutral (e.g. `initial shift up') and
the other for shifting from other gears (e.g. `shift up'). If you bind
the clutch to a key or button, rather than a continuous contral, you
will also bind two functions to the clutch controls. The reason is
that you may want different behavior from the clutch in these two
situations.
When shifting from neutral to first, you will let the clutch out
slowly to get the car started without stalling. When shifting to other
gears you will operate the clutch more quickly. You can make this
happen by binding both `initial shift up disegnage' and `shift up
disengage' to the same key or button, and using a larger value in the
`time' tage for `initial shift up disengage'.
File: vamos.info, Node: Dashboard, Next: Cars, Prev: Controls, Up: Top
1.5 Dashboard
=============
Several rows of text are printed along the bottom of the screen to
provide some information about the car, similar to the gauges on a
car's dashboard. You also get some information that you would not
normally see on a dashboard. Here's what is shown, going down the
columns, starting on the left.
RPM
The engine speed in revolutions per minute.
Torque
The current engine torque in Newton-meters.
Speed
The car's speed in kilometers per hour.
Gear
The currently selected gear. `N' stands for neutral and `R' is
for reverse.
Break and Throttle
The cyan bar shows the current brake setting. The magenta bar
shows the throttle setting. These bars are useful for evaluating
robot cars.
Slip Ratios
The slip ratios for each of the tires as a percentage. A slip
ratio is the difference between the speed of the contact patch and
the road moving beneath it, divided by the speed of the wheel's
hub. Rolling without sliding yields a slip ratio of zero.
Locking the wheels results in a slip ratio of 100%. Slip ratios
are useful for seeing how close you are to the limit of adhesion.
A ratio of 9% or 10% is usually close to optimal.
Fuel
Amount of fuel remaining in liters.
Air Density
The current density of the air that the car is driving through.
This number decreases in another car's slipstream.
Lap Time
The elapsed time for the current lap.
Last
The time taken to complete the previous lap and the difference
between this time and the best time.
Best
The shortest lap time so far.
frame/s
The current frame rate.
Sector
The number of the current timing sector and the elapsed time for
that sector.
Best
The best time for the current sector.
Last Sector
The time taken to complete the previous sector and the difference
between this time and the best time for that sector.
Distance
The distance from the start/finish line in meters.
File: vamos.info, Node: Cars, Next: Tracks, Prev: Dashboard, Up: Top
1.6 Cars
========
A number of different car definitions are provided. The car can be
selected with `-c <car>' or `--car=<car>', where `<car>' is one of the
following
`F1'
A modern Formula One car.
`F1-1967'
A late sixties Formula One car. For reasons I don't yet
understand, this car is very difficult to control.
`front-drive'
A front wheel drive car.
`GT'
`default-car'
A rear wheel drive sports car.
`trainer'
An under-powered car for beginners.
1.7 Car File Format
===================
The car definition goes inside a `car' tag. You can assign a name to
the car with the `name' attribute.
<car name="GT">
...
</car>
The sections below show how the various subsystems are defined.
1.7.1 Robot Parameters
----------------------
These settings define the target performance of the robot car. The
robot will use the specified slip ratio for acceleration. Deceleration
and lateral acceleration give the performance targets for braking and
cornering on a flat and level road with no aerodynamic assistance. The
actual targets are adjusted in real time for the slope of the track and
aerodynamic downforce.
Note that these are just targets. If they are set to values that
can't be achieved by the car the robot will drive the car off the road.
<robot>
<slip-ratio>9.0</slip-ratio>
<deceleration>1.4</deceleration>
<lateral-acceleration>1.5</lateral-acceleration>
</robot>
1.7.2 View
----------
The driver's point-of-view is set with the `position' tag. You may use
whatever units you like, as long as you're consistent. *Note Units::.
The horizontal field-of-view is set with the `field-width' tag. The
vertical field-of-view is calculated automatically from the current
window geometry.
<view>
<position>[ 1.3, 1.0, 0.8 ]</position>
<field-width>60.0</field-width>
</view>
1.7.3 Steering
--------------
The maximum steering angle is set with the `max-angle' tag. The
`exponent' detemines how linear the steering response is. A higher
number makes the steering less sensitive at small angles.
<steering>
<max-angle>10.0</max-angle>
<exponent>3.0</exponent>
</steering>
1.7.4 Drivetrain
----------------
The drivetrain section defines the engine, clutch, transmission and
differential.
<drivetrain>
<engine>
...
</engine>
<clutch>
...
</clutch>
<transmission>
...
</transmission>
<differential>
...
</differential>
</drivetrain>
The subsections of the drivetrain are described below.
<engine>
<position>[ 1.5, 1.0, 0.2 ]</position>
<mass>200.0</mass>
<max-power>3.0e5</max-power>
<peak-engine-rpm>8000.0</peak-engine-rpm>
<rpm-limit>10000.0</rpm-limit>
<inertia>0.10</inertia>
<idle>0.05</idle>
<start-rpm>1000</start-rpm>
<stall-rpm>500</stall-rpm>
<fuel-consumption>0.0001</fuel-consumption>
<sound>
<file>engine.wav</file>
<pitch>0.01</pitch>
<volume>0.8</volume>
<throttle-volume-factor>1.0</throttle-volume-factor>
<engine-speed-volume-factor>0.001</engine-speed-volume-factor>
</sound>
</engine>
The `position' and `mass' parameters affect the weight distribution
of the car. The torque curve is calculated from `max-power' and
`peak-engine-rpm' using a polynomial expression given in `Motor Vehicle
Dynamics, Genta (1997)', where `peak-engine-rpm' is the engine speed at
which the maximum power output (`max-power') is achieved. A rev limit
can be set with `rpm-limit'. The rotational inertia of the moving
parts is `inertia'. `idle' is the throttle position at idle. Starting
the engine initially sets the engine speed to `start-rpm'. Letting the
engine speed drop below `stall-rpm' makes the engine stall. The rate
of fuel consumption is set with `fuel-consumption'.
The engine sound is set in the `sound' section. `file' is the name
of a WAV file in the `data/sounds' directory. `throttle-volume-factor'
and `engine-speed-volume-factor' determine how the loudness of the
sound changes.
<clutch>
<sliding>0.5</sliding>
<radius>0.25</radius>
<area>0.2</area>
<max-pressure>1.0e4</max-pressure>
</clutch>
The torque on the clutch is found by dividing the clutch pressure by
the value in the `area' tag and multiplying by the `radius' and
`sliding' (friction) parameters.
The gear ratios can be defined in two different ways inside the
`transmission' tag. The ratios can be defined individually as in the
example below. The first number inside the brackets is the gear (-1 is
reverse), and the second is the clutch speed divided by the driveshaft
speed.
<transmission>
<gear-ratio>[ -1, -2.69 ]</gear-ratio>
<gear-ratio>[ 1, 2.53 ]</gear-ratio>
<gear-ratio>[ 2, 1.71 ]</gear-ratio>
<gear-ratio>[ 3, 1.42 ]</gear-ratio>
<gear-ratio>[ 4, 1.19 ]</gear-ratio>
<gear-ratio>[ 5, 1.04 ]</gear-ratio>
<shift-delay>0.2</shift-delay>
</transmission>
Alternatively, the number of gears and the highest and lowest ratios
can be specified. The other gears will be calculate such that the
reciprocals of the ratios are equally spaced.
<transmission>
<forward-gears>5</forward-gears>
<first-ratio>3.21</first-ratio>
<last-ratio>1.10</last-ratio>
<shift-delay>0.2</shift-delay>
</transmission>
The `shift-delay' tag tells how long it takes to change gears. For
a paddle-shifter, like a modern Formula One car, `shift-delay' can be
set to zero.
1.7.5 Fuel Tank
---------------
The fuel tank's position, the current volume of fuel and the density of
the fuel affect the car's weight distribution. The `capacity' tag sets
the maximum volume of fuel that the tank can hold. The initial volume
is set with the `volume' tag. The density of the fuel is set with
`fuel-density'.
<fuel-tank>
<position>[ 1.00, 1.00, 0.25 ]</position>
<capacity>100.0</capacity>
<volume>100.0</volume>
<fuel-density>0.8</fuel-density>
</fuel-tank>
1.7.6 Wheels
------------
The `wheel' section contains information about the suspension, tire,
and brakes as well as the wheel itself. The `side' and `end'
attributes tell where the wheel is located. The values of these
attributes are important.
The `steered' tag tells that the wheel responds to steering input.
The `driven' tag tells that torque from the engine is applied to the
wheel. Only two wheels may have a `steered' tag, and only two may have
a `driven' tag.
<wheel side="right" end="front">
<steered/>
<driven/>
<position>[ 3.0, 0.05, -0.1 ]</position>
<mass>30.0</mass>
<restitution>0.1</restitution>
<suspension>
...
</suspension>
<tire>
...
</tire>
<brakes>
...
</brakes>
<wheel>
Values set in one wheel section are persistent; if you want the same
value for another wheel, you do not need set it.
The suspension, tire, and brakes sections are described below.
1.7.7 Suspension
----------------
<suspension>
<position>[ 3.0, 0.35, -0.1 ]</position>
<hinge>[ 2.0, 0.35, 0.3 ]</hinge>
<spring-constant>22000.0</spring-constant>
<bounce>2000.0</bounce>
<rebound>2000.0</rebound>
<travel>0.4</travel>
<max-compression-velocity>10.0</max-compression-velocity>
<camber>-2.0</camber>
<caster>5.0</caster>
<toe>-2.0</toe>
</suspension>
The `hinge' is the center of the wheel's path as the suspension moves.
The location of the hinge is determined by suspension geometry, and may
be outside of the car itself. Currently, this parameter has no effect
of performance. It may be used in the future for configuring anti-dive
and anti-squat suspension geometries.
`bounce' and `rebound' are the damping coefficients for compression
and expansion of the suspension, respectively. If the speed at which
the suspension is compressed, or expanded exceeds the value in
`max-compression-velocity', the dampers "lock up."
Wheel alignment is set with the `camber', `caster', and `toe' tags.
All angles are in degrees.
1.7.8 Tires
-----------
The `longitudinal', `transverse', and `aligning' section each contain a
vector of "magic formula" coefficients as presented in `Motor Vehicle
Dynamics, Genta (1997)'. The two elements of `rolling-resistance' are
the constant and velocity-squared terms, respectively.
<tire>
<friction>
<longitudinal>
[ 1.65, 0.0, 1690.0, 0.0, 229.0, 0.0, 0.0, 0.0, -10.0, 0.0, 0.0 ]
</longitudinal>
<transverse>
[ 1.80, 0.0, 1690.0, 800.0, 6.03, 0.0, -0.359, 1.0, 0.0, -6.11e-3, -3.22e-2, 0.0, 0.0, 0.0, 0.0 ]
</transverse>
<aligning>
[ 2.07, -6.49, -21.9, 0.416, -21.3, 2.94e-2, 0.0, -1.20, 5.23, -14.8, 0.0, 0.0, -3.74e-3, 3.89e-2, 0.0, 0.0, 0.639, 1.69 ]
</aligning>
</friction>
<radius>0.310</radius>
<rolling-resistance>[ 1.3e-2, 6.5e-6 ]</rolling-resistance>
<rotational-inertia>10.0</rotational-inertia>
</tire>
1.7.9 Brakes
------------
<brakes>
<friction>0.8</friction>
<max-pressure>2.0e6</max-pressure>
<front-bias>0.55</front-bias>
<radius>0.2</radius>
<area>0.01</area>
</brakes>
`front-bias' is the fraction of braking pressure applied to the front
brakes.
1.7.10 Particles and Contact Points
-----------------------------------
Particles affect the mass distribution of the car.
<particle>
<position>[ 2.0, 1.0, 0.5 ]</position>
<mass>100.0</mass>
</particle>
Contact points are particles that participate in collisions. The
material specified in the `material' tag (either "metal" or "rubber")
determines the sound made when contact is detected. The coefficients
of friction and restitution are set with the `friction' and
`restitution' tags, respectively.
<contact-point>
<mass>40.0</mass>
<position>[ 0.0, 0.0, 0.0 ]</position>
<material>metal</material>
<friction>0.5</friction>
<restitution>0.1</restitution>
</contact-point>
1.7.11 Drag and Wings
---------------------
The aerodynamic properties of the car are determined by the `drag' and
`wing' sections. The frontal area and coefficient of drag, set it
`frontal-area' and `drag-coefficient', are used to calculate the drag
force.
<drag>
<position>[ 2.0, 1.0, 0.25 ]</position>
<frontal-area>2.0</frontal-area>
<drag-coefficient>0.3</drag-coefficient>
</drag>
Downforce can be added with wings. The amount of downforce is
determined by the value in the `lift-coefficient' tag. If the lift
coefficient is positive, upforce is generated. This is usually
undesirable for cars. The `efficiency' determines how much drag is
added as downforce increases. The `surface-area' is the surface area
of the wing. This value is also used in the drag calculation.
<wing>
<position>[ 0.0, 0.9, 0.5 ]</position>
<frontal-area>0.2</frontal-area>
<surface-area>0.5</surface-area>
<lift-coefficient>-4.0</lift-coefficient>
<efficiency>0.5</efficiency>
</wing>
File: vamos.info, Node: Tracks, Next: Worlds, Prev: Cars, Up: Top
1.8 Tracks
==========
Once you get bored with the default, you might want to try driving on
some different tracks. The track can be selected using command line
arguments. Use either `vamos -t <track>' or `vamos --track==<track>',
where `<track>', is the name of one of the XML files in the
`data/tracks' directory. There are files for almost all of the Formula
One circuits for the past couple of decades, plus a few more. These
include
`drag'
A striaight flat strip of road.
`Monza'
The high-speed Italian circuit.
`Peanut'
`default-track'
A simple track.
`Road_Atlanta'
The Georgia-shaped track in Georgia.
`Silverstone'
The home of the British grand prix.
`skid_pad'
A cirular track for testing handling.
`Spa'
The Spa-Francorchamps track in Belgium.
`Suzuka'
The track for many Japanase Grands Prix.
You can use the `trk-convert' program to turn a track file for RARS
(Robot Auto Racing `http://rars.sourceforge.net') into a C++ track file
for Vamos. The converted files usually need some adjusting, so you'll
have to learn a little about Vamos track files.
1.9 Track File Format
=====================
Tracks are defined in XML files. Here's the beginning of a track file.
<track name="Peanut">
<racing-line show="0">
<iterations>800</iterations>
<stiffness>1.0</stiffness>
<damping>0.01</damping>
<margin>1.6</margin>
<resolution>14.0</resolution>
</racing-line>
1.9.1 Racing Line
-----------------
The racing line section is optional. A good line is calculated for
almost all tracks using the default parameters (shown). Changing the
`show' parameter to 1 will cause the racing line to be drawn on the
track. However, the `-l' option is a more convenient way to do this.
Use more iterations if the racing line does not converge to something
reasonable. You can try fewer to reduce the calculation time.
The racing line is calculated by simulating a chain of masses with
springs that tend to straighten the chain. Stiffness sets the spring
constant. Damping prevents runaway oscillation.
The margin is how close to the edge of the road the line is allowed
to get.
Resolution is the distance between masses. This parameter defaults
to the width of the road at the starting line.
The racing line can be modified by the tags `racing-line-adjustment'
and `curvature-factor' in the `road'. See below.
1.9.2 The Sky Box
-----------------
<sky>
<sides>textures/sky_sides.png</sides>
<top>textures/sky_top.png</top>
<bottom>textures/sky_bottom.png</bottom>
<smooth/>
</sky>
The `sky' section describes the sky box, which is a cube onto which a
background is mapped. The `sides' image is wrapped around the front,
right, back, and left sides of the sky box. The optional `smooth' tag
can improve the quality of the sky box images.
1.9.3 Materials
---------------
After the sky box, the properties of the various materials that make up
the track are defined.
<material name="track" type="asphalt">
<friction>1.0</friction>
<restitution>0.1</restitution>
<rolling>1.0</rolling>
<drag>0.0</drag>
<bump-amplitude>0.01</bump-amplitude>
<bump-wavelength>100.0</bump-wavelength>
<texture>
<file>textures/track2.png</file>
<length>200.0</length>
<smooth/>
<mipmap/>
</texture>
</material>
The name is used to identify the material in other parts of the file.
The type helps determine what sound is played. The type must be one of
rubber, metal, asphalt, concrete, grass, gravel, or dirt.
The `friction' tag sets the relative friction of the surface. If,
for example, you want to specify another surface that has half the
friction of asphalt, you whould set the friction value to 0.5. The
calculation of the actual frictional force involves the car.
Similarly, relative values of the coefficient of restitution, rolling
resistance, and velocity-dependent drag are set with the `restitution',
`rolling', and `drag' tags.
The bumpiness of the surface is set with the `bump-amplitude', and
`bump-wavelength' tags. They define a sinusiodal variation in the
track's elevation. You may use whatever units you like, as long as
you're consistent. *Note Units::.
The texture image is set in the `texture' section. The file is the
name of a PNG image file. The physical size that the image covers is
set with the `length' and `width' tags. In this example, the `width'
tag is omitted. As a result, the texture is stretched to fit the
width of the track.
The `smooth' and `mipmap' tags improve the quality of the images,
but they also reduce the frame rate.
1.9.4 Segments
--------------
The materials are grouped into "segments" that describe the materials
for the track, kerbs, shoulders, and barriers.
<segment name="left turn">
[ wall grass kerb track kerb gravel tires ]
</segment>
The name is used to identify the segment in other parts of the file.
Inside the `segment' tag is an array of material names. The material
of the right-side barrier (as seen from a car traveling forward around
the track) is first.
1.9.5 Track Geometry
--------------------
The track is made up of `road' sections. Here is a simple `road'
section
<road segment="left turn">
<resolution>5.0</resolution>
<length>130.0</length>
<radius>160.0</radius>
</road>
The `segment' attribute names a list of materials defined earlier in
the file. The `resolution' sets the size of the quadrilateral
divisions in the road section. The smaller the resolution, the more
closely the section approximates a smooth curve. The length and width
are given in meters. However, any system of units can be used as long
as they are used consistently throughout the simulation for both
derived and fundamental quantities.
The first road section must set the width of the track and shoulder,
and also the height of the barriers. These dimensions are specified as
(distance, width) pairs. Any number of pairs may be specified for a
given width, the program will interpolate linearly between specified
points.
<!-- front straight -->
<road segment="straight pit">
<resolution>10.0</resolution>
<length>100.0</length>
<left-width>[ 0.0, 25.0 ]</left-width>
<right-width>[ 0.0, 25.0 ]</right-width>
<left-road-width>[ 0.0, 8.0 ]</left-road-width>
<right-road-width>[ 0.0, 8.0 ]</right-road-width>
<left-wall-height>2.0</left-wall-height>
<right-wall-height>2.0</right-wall-height>
<elevation>[ 20.0, 0.0 ]</elevation>
<elevation>[ 200.0, 5.0 ]</elevation>
</road>
Similarly, any number of elevation points may be specified. A spline
is used to interpolate between elevation points to achieve smooth
elevation changes.
The `racing-line-adjustment' adjusts the edges of the track left
(positive) or right (negative) for the purpose of calculating the racing
line. It is often useful to do this to shift the line toward the edge
of the track so that the robot cars will run onto the kerbs.
If the cars go too fast or too slow for on a particular segment, the
`curvature-factor' can be specified to make the robots think the racing
line is curved more or less than it actually is. The actual curvature
is multiplied by this number. If it's greater than one the cars will
go slower; if it's less they'll go faster.
1.9.6 Braking Markers
---------------------
Braking markers are signs that show the distance to an upcoming turn.
For turns approached a high speed, markers at 150 m, 100 m, and 50 m
are typically shown.
<road>
...
<braking-marker>
<file>textures/50.png</file>
<distance>50.0</distance>
<size>[ 1.4, 0.7 ]</size>
<offset>[ 2.0, 0.0 ]</offset>
<side>right</side>
</braking-marker>
<braking-marker>
<file>textures/100.png</file>
<distance>100.0</distance>
</braking-marker>
<braking-marker>
<file>textures/150.png</file>
<distance>150.0</distance>
</braking-marker>
...
</road>
Once the size and offset parameters have been set, they do not need
to be specified again unless you want to use different values.
1.9.7 Kerbs
-----------
Concrete kerbs are often placed along the insides of curves, and on the
opposite side at the curve exits. I'm not really sure why.
Nonetheless, kerbs can be specified in the road sections.
<road>
...
<left-kerb>
<start>
<distance>10.0</distance>
<transition>
<length>4.0</length>
<width>1.0</width>
</transition>
</start>
<end>
<distance>100.0</distance>
<transition>
<length>4.0</length>
<width>1.0</width>
</transition>
</end>
<profile>[ 1.0, 0.1 ][ 3.0, 0.1 ][ 3.1, 0.0 ]</profile>
</left-kerb>
<right-kerb>
...
</right-kerb>
...
</road>
Each road section can have a left-side and a right-side kerb. A set
of coordinates of the form [ distance-from-edge-of-track,
elevation-above-track ] set the shape of the kerb in the `profile' tag.
A [ 0.0, 0.0 ] coordinate is inserted automatically.
The `start' and `end' tags tell where and how the kerb begins and
ends. If the distance is positive it is relative to the beginning of
the road section. If it's negative it is measured from the end. The
distance may be omitted for either or both ends. The default start and
end distances are zero and the end of the track, respectively.
The `transition' section tells how the ends of the kerb are capped.
In the example above, the kerb tapers down track level and a width of
1.0 m in a distance of 4.0 m. The transition does not add length to the
kerb. The `start' and `end' tags specify the endpoints of the kerb
including the transitions.
If the `end' tag is omitted on one segment and the `start' tag is
omitted on the next, the kerb will run seamlessly across the segment
boundary. If the kerb should run through the segment and connect with
kerbs on the next and previous segments an empty tag (`<left-kerb/>' or
`<right-kerb/>') will do.
Once the transition length and width, and the profile are set they do
not need to be specified again unless you want to use different values.
You can use `<transition/>' to specify a transition with the previously
set values. For example, this kerb runs the entire length of its road
section and is capped with transitions at both ends.
<right-kerb>
<start><transition/></start>
<end><transition/></end>
</right-kerb>
If there's no `start' tag, the kerb starts at the beginning of the
road section with no transition. If there's to `end', the kerb ends at
the end of the road section. To make the kerb join smoothly across two
road sections, omit the `end' in the first section, and omit the
`start' in the second.
Kerbs are typically serrated. Again, I don't know why. This can be
simulated by setting the bump parameters on the kerb material defined
near the beginning of the track file.
1.9.8 Closing a Circuit
-----------------------
Adjusting a track to make meet the beginning seamlessly is tedious. If
a `<circuit/>' tag is included, the program will make the adjustments
automatically. You can specify how many of the last segments will be
adjusted with the `segments' attribute. For example, with `<circuit
segments="2"/>' only the last two segments will be changed. Note the
quotes around the value (required by the XML standard) and the trailing
slash.
Allowed values for the `segments' tag are 0, 1, 2, and 3. The
default is 3.
`3'
Adjust the length of the next-to-last segment (which must be a
curve), to make the last segment parallel to the first. Adjust
the length of the third-to-last segment (which must be straight)
to put the last segment in line with the first. Adjust the length
of the last segment so that it meets the beginning of the first.
`2'
Adjust the radius and length of the next-to-last segment to align
the last with the first. Adjust the length of the last segment so
that it meets the beginning of the first.
`1'
Adjust the length of the last segment so that it meets the
beginning of the first.
`0'
Adjust nothing.
In all cases (including 0) the elevation curve is forced to close.
If the track can not be closed with the specified adjustments, or the
requirements about what segments must be stright or curved, the
exception `Vamos_Track::Can_Not_Close' is thrown.
File: vamos.info, Node: Worlds, Next: Units, Prev: Tracks, Up: Top
1.10 Worlds
===========
The "world" specifies various environmental factors. Here's the entire
default world file.
<world name="Earth">
<!-- Acceleration due to gravity -->
<gravity>9.8</gravity>
<maximum-time-step>0.01</maximum-time-step>
<atmosphere>
<!-- Air density -->
<density>1.2</density>
<!-- Wind velocity -->
<velocity>[ 0.0, 0.0, 0.0 ]</velocity>
</atmosphere>
<lighting>
<!-- Direction to the light source -->
<source-position>[ 0.0, -1.0, 1.0 ]</source-position>
<!-- RGB for ambient light -->
<ambient>[ 0.7 , 0.7, 0.7 ]</ambient>
</lighting>
</world>
Here is a description of the sections.
`gravity'
Acceleration due to gravity. The typical value for Earth is 9.8
m/s^2.
`maximum-time-step'
Each frame in the simulation will be sub-divided into time steps no
larger than this value. If you see jitter when the car is stopped,
try lowering the maximum time step. However, you may take a
performance hit, if the value is too small.
`atmosphere'
Density of the air and wind velocity.
`lighting'
Light source position and ambient light level.
Other world files can be specified with the `--world=' or `-w'
options. Just for fun, a world file for the moon is provided.
File: vamos.info, Node: Units, Next: Code Reference, Prev: Worlds, Up: Top
2 Units
*******
A number that describes a physical quantity is meaningless unless the
units of measure are given. If we have a length of 20, we don't know
if it's 20 meters, 20 feet, or 20 light years. Despite this fact,
there are no units specified in Vamos.
Consider the fundamental quantities to be time, length, and mass.
From these, you can derive the units for any quantity used in the
simulation. For instance, the units on velocity are a length unit
divided by a time unit. Force units are mass times length divided by
time squared. As long as the fundamental and derived units are
consistent, it does not matter what base units are used.
There's one exception. Since the simulation relies on library
functions for timing information, and these libraries use seconds, the
unit of time must be seconds.
I always use SI (metric) units because it's easy to keep the base and
derived units consistent. The SI base units are the meter (m) for
length and kilogram (kg) for mass. Power is derived quantity with
units of Watts. A Watt is a kg*m^2/s^3. If you use feet and slugs as
your base unit, then your power will be in slug*ft^2/s^3; you can't
simply use horsepower.
Derived units used in the simulation are
* area (distance^2)
* volume (distance^3)
* speed (distance/time)
* acceleration (distance/time^2)
* force (mass*acceleration)
* torque (force*distance)
* engine power (force*distance/time)
* spring constant (force/distance)
* damping (force/speed)
* density (mass/volume)
There are some places where non-SI units are used. All angles are
specified in degrees. Engine speeds are specified in rotations per
minute (RPM). The coefficients for tire friction have their customary
units.
File: vamos.info, Node: Code Reference, Next: Building Vamos, Prev: Units, Up: Top
3 Code Reference
****************
The code is devided into four modules that reside in four namespaces,
`Vamos_Geometry', `Vamos_Body', `Vamos_Track' and `Vamos_World'. Each
namespace contains the code for a library. These libraries are
`libvamos-geometry', `libvamos-body', `libvamos-track', and
`libvamos-world'. The geometry library has classes for vectors,
matrices and curves. The body library has a class for a rigid body and
classes for a car and its parts. It also has other classes that are
needed by more than one of the other libraries. The track library has
the classes needed for building a track. The world library handles a
rigid body's interaction with the track.
* Menu:
* The Geometry Library:: Vectors, matrices, curves, etc.
* The Media Library:: Code for sound, images, 3D models.
* The Track Library:: The driving surface.
* The Body Library:: Cars and other rigid bodies.
* The World Library:: The world mediates interactions.
The geometry library is used by both the body and world libraries.
The body library is used by the world library. The dependency graph
looks like this:
libvamos-geometry
/ |
/ |
libvamos-media |
\ |
\ |
----+----
/ | \
/ | \
libvamos-track | libvamos-body
\ | /
\ | /
libvamos-world
Libraries farther down the graph depend on the libraries above them. If
you only need the services of the geometry library, then you only have
one library to link. If you use the body library, then you need to link
the geometry and media libraries as well. If you use the world library,
then you need to link all five. When linking multiple libraries you may
need to make sure that `libvamos-geometry' is linked first, followed by
`libvamos-body', and then `libvamos-world'. If you get errors from the
linker about undefined references to functions defined in one of these
libraries, then you may have to adjust the link order.
Care was taken to avoid a dependency of `libvamos-track' on
`libvamos-body' and vice versa. This allows cars and tracks to tested
independently.
File: vamos.info, Node: The Geometry Library, Next: The Media Library, Up: Code Reference
3.1 The Geometry Library
========================
The geometry module is a collection of mathematical constants,
functions, and objects. There are also a few less mathematical classes
that are required by more than one other module. This is done to avoid
dependency problems.
3.2 Three_Vector
================
A `Three_Vector' represents a vector in three dimensions. Some
supported operations are
* subscripting using `[]'
* vector addition and subtraction using `+' and `-'
* multiplication and division by a scalar using `*' and `/'
* left and right matrix multiplication using `*'
* dot and cross products using the `dot()' and `cross()'methods
* projection onto another vector using the `project()' method
* magnitude using the `abs()' method
Matrix multiplication is done with a `Three_Matrix'.
3.3 Three_Matrix
================
A `Three_Matrix' represents 3x3 matrix. It's suitable for representing
a three-dimensional rotation matrix or inertia tensor. Some suported
operations are
* subscripting using `[]'
* matrix addition and subtraction using `+' and `-'
* multiplication and division by a scalar using `*' and `/'
* left and right vector multiplication using `*'
* matrix multiplication using `*'
* eigenvalue and eigenvector determination
* inversion
3.4 Inertia_Tensor
==================
An inertia tensor is a matrix that describes a rigid body's responce to
torques. The `Inertia_Tensor' generates the tensor from the locations
of masses on a body. The masses and positions are specified using the
`add()' method. The `inertia()' method returns the moment of inertia
for a force applied at a particular point on the body.
3.5 Two_Point
=============
A `Two_Point' describes a point in a plane. It is a `struct' with two
data members, `x' and `y'. A constructor is provided for initializing
the members. No vector operations are supported, and some of the
supported operations are undefined for vectors. That's why this class
is called `Two_Point' and not `Two_Vector'. The supported operations
are scalar and member-wise addition, subtraction, multiplication, and
division. For the scalar versions, the operation is performed on each
member.
`Spline' is the only user of `Two_Point'. Perhaps it should be
defined in `Spline''s header so that there's less temptation to use
`Two_Point' inappropriately.
3.6 Spline
==========
`Spline' is a class for a parametric cubic spline interpolation between
points. A vector of `Two_Point's through which the curve passes and
angle of the curve at the first and last points are passed to the
constructor.
`Spline's are used to make smooth road elevation changes and banking
transitions.
3.7 Surface
===========
A `Surface' describes the friction, rolling resistance, restitution and
texture image of a surface such as pavement, grass or gravel.
3.8 Texture_Image
=================
The `Texture Image' class provides a convenient way of reading a
`*.ppm' image file from the disk and for getting information about the
image.
3.9 Conversions
===============
The header file `Conversions.h' contains a few functions for performing
frequently-used unit conversions. Currently, there are conversions for
radians and degress, radians per second and revolutions per minute, and
meters per second and kilometers per hour.
File: vamos.info, Node: The Media Library, Next: The Track Library, Prev: The Geometry Library, Up: Code Reference
3.10 The Media Library
======================
File: vamos.info, Node: The Track Library, Next: The Body Library, Prev: The Media Library, Up: Code Reference
3.11 The Track Library
======================
A `Track' is a collection of straight and curved pieces of road. These
pieces are described by classes derived from `Road_Segment'.
Currently, we have a straight segment class (`Straight_Road'), and a
circle arc segment class (`Arc_Road'). The track is assembled so that
there are no corners where two segments join.
If you look at the code you'll find a class for a segment that
smoothly curves through a set of given points (`Spline_Road'). This
class has been commented out because I don't know how to do the
transformation from world coordinates to track coordinates for a spline.
The elevation and banking at any number of points on a segment can be
specified. The specified points are interpolated with a cubic spline so
that the transitions are smooth.
Track o---Road_Segment
^ ^
/ \
Straight_Road Arc_Road
File: vamos.info, Node: The Body Library, Next: The World Library, Prev: The Track Library, Up: Code Reference
3.12 The Body Library
=====================
A `Body' describes a three-dimensional rigid body made up of point
particles. These particles are described by `Particle' and its
subclasses. Position and orientation for both `Body's and `Particle's
is provided by the `Frame' base class. The `Car' class is derived from
`Body'
Frame
^ ^
/ \
Body o---Particle
^
|
Car
* Menu:
* Frame:: A coordinate system.
* Particle:: A body is made up of point particles.
* Body:: A rigid body.
* Car:: A drivable body.
File: vamos.info, Node: Frame, Next: Particle, Up: The Body Library
3.12.1 Frame
------------
File: vamos.info, Node: Particle, Next: Body, Prev: Frame, Up: The Body Library
3.12.2 Particle
---------------
File: vamos.info, Node: Body, Next: Car, Prev: Particle, Up: The Body Library
3.12.3 Body
-----------
File: vamos.info, Node: Car, Prev: Body, Up: The Body Library
3.12.4 Car
----------
3.12.4.1 Drivetrain
...................
3.12.4.2 Wheel
..............
File: vamos.info, Node: The World Library, Prev: The Body Library, Up: Code Reference
3.13 The World Library
======================
To avoid dependencies, `Track', `Atmosphere', and `Body' were each
designed so that they know nothing about the others. It is the purpose
of the `World' class to mediate any interactions among those classes.
Because `Track', `Atmosphere', and `Body' are independent, it is
neccessary that `World' depend on each of these classes. A subclass of
`World' that provides an interface to the input methods of `Car' is
provided. It's called `Car_World'. (Apologies to Marcus Hewat,
creator of the Carworld program,
`http://perso.club-internet.fr/hewat/carworld/carworld.htm'. Aside
from some bits of code I stole for reading textures from files and
drawing text on the screen, this project is unrelated to Carworld.)
World
o ^ o o---.
/ | \ \
Track | Body Atmosphere
| ^
Car_World |
o |
\ |
Car
The `World' base class doesn't do any graphics. If you want to see
the results of the simulation on screen, you must derive an appropriate
class and define the `draw()' method. An example of such a class that
uses OpenGL, `Gl_Car_World', is provided. You must also use subclasses
of Track and Car (such as `Gl_Track' and `Gl_Car') that use the same
graphics system if you wish to see instances of those objects.
A typical application will construct a `Track', `Atmosphere', and
`Car', and then construct a `World' by passing pointers to those
objects. The simulation is started by calling the `World''s `start()'
method. The `World' is responsible for initializing the graphics
system (if used) and starting the event loop.
3.13.1 Atmosphere
-----------------
To be written.
File: vamos.info, Node: Building Vamos, Next: Copying, Prev: Code Reference, Up: Top
Appendix A Building Vamos
*************************
A.1 Downloading
===============
You can get the latest release by going to the Vamos home page,
`http://vamos.sourceforge.net', and following the "Download" link.
Another way to get there is to go through the SourceForge project page,
`http://sourceforge.net/projects/vamos'.
A.2 Dependencies
================
Vamos makes use of some external libraries. These libraries need to be
present in order to compile Vamos.
OpenGL-compatible libraries, including the OpenGL Utility Library
(GLU) and the OpenGL Utility Toolkit (GLUT) must be installed. Mesa
`http://www.mesa-3d.org' works fine. In addition, you need accelerated
video hardware. Some video cards require specific GL implementations.
SDL `http://www.libsdl.org' is used for event handling (keys, mouse,
and joystick). Sound is handled by OpenAL
`http://connect.creativelabs.com/openal'.
You will also need a reasonably up-to-date C++ compiler.
Specifically, it must handle namespaces. Gcc version 2.96 and later,
including 3.x, and 4.x should do. See `http://gcc.gnu.org'. The code
is intended to be portable, standard C++, so other compilers should
work as well.
A.3 Compiling
=============
After downloading the source archive (the `tar.gz' file), unpack it
with the `tar' command, or some other utility. All of the files in the
archive are placed in a subdirectory. If the archive is
`vamos-1.2.3.tar.gz', the files are placed in `vamos-1.2.3'.
Vamos uses the GNU Autotools (`automake', `autoconf', and `libtool')
to check for prerequisites and handle different architectures. Change
to the directory created by un-archiving and type `./configure'. Type
`./configure --help' to see the options accepted by `configure'. I
have only tried to compile Vamos on GNU/Linux and Cygwin/Win32
platforms. Please write me if you find an architecture that is not
handled correctly.
The `configure' script generates the `Makefile's needed to compile
the program. Issue the `make' command to start the compilation. If
you encounter errors, or warnings that you think I should know about,
please contact me.
If the compilation succeeds, you can install the libraries, headers,
and application by typing `make install'. You may need to be a
privileged user to install software on your system. You do not need to
install the program to run the application. Switch to the `vamos'
directory and run `./vamos' to try the application without installing.
File: vamos.info, Node: Copying, Next: Concept Index, Prev: Building Vamos, Up: Top
Appendix B Copying
******************
Vamos may be copied according to the terms of the GNU General Public
License (GNU GPL). The license is in the file COPYING in the top-level
directory of the source code.
This documentation may be copied according to the terms of the GNU
Free Documentation License (GNU FDL) which is printed below.
B.1 GNU Free Documentation License
==================================
Version 1.1, March 2000
Copyright (C) 2000 Free Software Foundation, Inc.
59 Temple Place, Suite 330, Boston, MA 02111-1307, USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
0. PREAMBLE
The purpose of this License is to make a manual, textbook, or other
written document "free" in the sense of freedom: to assure everyone
the effective freedom to copy and redistribute it, with or without
modifying it, either commercially or noncommercially. Secondarily,
this License preserves for the author and publisher a way to get
credit for their work, while not being considered responsible for
modifications made by others.
This License is a kind of "copyleft", which means that derivative
works of the document must themselves be free in the same sense.
It complements the GNU General Public License, which is a copyleft
license designed for free software.
We have designed this License in order to use it for manuals for
free software, because free software needs free documentation: a
free program should come with manuals providing the same freedoms
that the software does. But this License is not limited to
software manuals; it can be used for any textual work, regardless
of subject matter or whether it is published as a printed book.
We recommend this License principally for works whose purpose is
instruction or reference.
1. APPLICABILITY AND DEFINITIONS
This License applies to any manual or other work that contains a
notice placed by the copyright holder saying it can be distributed
under the terms of this License. The "Document", below, refers to
any such manual or work. Any member of the public is a licensee,
and is addressed as "you".
A "Modified Version" of the Document means any work containing the
Document or a portion of it, either copied verbatim, or with
modifications and/or translated into another language.
A "Secondary Section" is a named appendix or a front-matter
section of the Document that deals exclusively with the
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Document's overall subject (or to related matters) and contains
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The relationship could be a matter of historical connection with
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The "Invariant Sections" are certain Secondary Sections whose
titles are designated, as being those of Invariant Sections, in
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Examples of suitable formats for Transparent copies include plain
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You may copy and distribute the Document in any medium, either
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You may also lend copies, under the same conditions stated above,
and you may publicly display copies.
3. COPYING IN QUANTITY
If you publish printed copies of the Document numbering more than
100, and the Document's license notice requires Cover Texts, you
must enclose the copies in covers that carry, clearly and legibly,
all these Cover Texts: Front-Cover Texts on the front cover, and
Back-Cover Texts on the back cover. Both covers must also clearly
and legibly identify you as the publisher of these copies. The
front cover must present the full title with all words of the
title equally prominent and visible. You may add other material
on the covers in addition. Copying with changes limited to the
covers, as long as they preserve the title of the Document and
satisfy these conditions, can be treated as verbatim copying in
other respects.
If the required texts for either cover are too voluminous to fit
legibly, you should put the first ones listed (as many as fit
reasonably) on the actual cover, and continue the rest onto
adjacent pages.
If you publish or distribute Opaque copies of the Document
numbering more than 100, you must either include a
machine-readable Transparent copy along with each Opaque copy, or
state in or with each Opaque copy a publicly-accessible
computer-network location containing a complete Transparent copy
of the Document, free of added material, which the general
network-using public has access to download anonymously at no
charge using public-standard network protocols. If you use the
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begin distribution of Opaque copies in quantity, to ensure that
this Transparent copy will remain thus accessible at the stated
location until at least one year after the last time you
distribute an Opaque copy (directly or through your agents or
retailers) of that edition to the public.
It is requested, but not required, that you contact the authors of
the Document well before redistributing any large number of
copies, to give them a chance to provide you with an updated
version of the Document.
4. MODIFICATIONS
You may copy and distribute a Modified Version of the Document
under the conditions of sections 2 and 3 above, provided that you
release the Modified Version under precisely this License, with
the Modified Version filling the role of the Document, thus
licensing distribution and modification of the Modified Version to
whoever possesses a copy of it. In addition, you must do these
things in the Modified Version:
A. Use in the Title Page (and on the covers, if any) a title
distinct from that of the Document, and from those of
previous versions (which should, if there were any, be listed
in the History section of the Document). You may use the
same title as a previous version if the original publisher of
that version gives permission.
B. List on the Title Page, as authors, one or more persons or
entities responsible for authorship of the modifications in
the Modified Version, together with at least five of the
principal authors of the Document (all of its principal
authors, if it has less than five).
C. State on the Title page the name of the publisher of the
Modified Version, as the publisher.
D. Preserve all the copyright notices of the Document.
E. Add an appropriate copyright notice for your modifications
adjacent to the other copyright notices.
F. Include, immediately after the copyright notices, a license
notice giving the public permission to use the Modified
Version under the terms of this License, in the form shown in
the Addendum below.
G. Preserve in that license notice the full lists of Invariant
Sections and required Cover Texts given in the Document's
license notice.
H. Include an unaltered copy of this License.
I. Preserve the section entitled "History", and its title, and
add to it an item stating at least the title, year, new
authors, and publisher of the Modified Version as given on
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the Document, create one stating the title, year, authors,
and publisher of the Document as given on its Title Page,
then add an item describing the Modified Version as stated in
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J. Preserve the network location, if any, given in the Document
for public access to a Transparent copy of the Document, and
likewise the network locations given in the Document for
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it refers to gives permission.
K. In any section entitled "Acknowledgments" or "Dedications",
preserve the section's title, and preserve in the section all
the substance and tone of each of the contributor
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L. Preserve all the Invariant Sections of the Document,
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or the equivalent are not considered part of the section
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M. Delete any section entitled "Endorsements". Such a section
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N. Do not retitle any existing section as "Endorsements" or to
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If the Modified Version includes new front-matter sections or
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and a passage of up to 25 words as a Back-Cover Text, to the end
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5. COMBINING DOCUMENTS
You may combine the Document with other documents released under
this License, under the terms defined in section 4 above for
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all of the Invariant Sections of all of the original documents,
unmodified, and list them all as Invariant Sections of your
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the list of Invariant Sections in the license notice of the
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In the combination, you must combine any sections entitled
"History" in the various original documents, forming one section
entitled "History"; likewise combine any sections entitled
"Acknowledgments", and any sections entitled "Dedications". You
must delete all sections entitled "Endorsements."
6. COLLECTIONS OF DOCUMENTS
You may make a collection consisting of the Document and other
documents released under this License, and replace the individual
copies of this License in the various documents with a single copy
that is included in the collection, provided that you follow the
rules of this License for verbatim copying of each of the
documents in all other respects.
You may extract a single document from such a collection, and
distribute it individually under this License, provided you insert
a copy of this License into the extracted document, and follow
this License in all other respects regarding verbatim copying of
that document.
7. AGGREGATION WITH INDEPENDENT WORKS
A compilation of the Document or its derivatives with other
separate and independent documents or works, in or on a volume of
a storage or distribution medium, does not as a whole count as a
Modified Version of the Document, provided no compilation
copyright is claimed for the compilation. Such a compilation is
called an "aggregate", and this License does not apply to the
other self-contained works thus compiled with the Document, on
account of their being thus compiled, if they are not themselves
derivative works of the Document.
If the Cover Text requirement of section 3 is applicable to these
copies of the Document, then if the Document is less than one
quarter of the entire aggregate, the Document's Cover Texts may be
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8. TRANSLATION
Translation is considered a kind of modification, so you may
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4. Replacing Invariant Sections with translations requires special
permission from their copyright holders, but you may include
translations of some or all Invariant Sections in addition to the
original versions of these Invariant Sections. You may include a
translation of this License provided that you also include the
original English version of this License. In case of a
disagreement between the translation and the original English
version of this License, the original English version will prevail.
9. TERMINATION
You may not copy, modify, sublicense, or distribute the Document
except as expressly provided for under this License. Any other
attempt to copy, modify, sublicense or distribute the Document is
void, and will automatically terminate your rights under this
License. However, parties who have received copies, or rights,
from you under this License will not have their licenses
terminated so long as such parties remain in full compliance.
10. FUTURE REVISIONS OF THIS LICENSE
The Free Software Foundation may publish new, revised versions of
the GNU Free Documentation License from time to time. Such new
versions will be similar in spirit to the present version, but may
differ in detail to address new problems or concerns. See
`http://www.gnu.org/copyleft/'.
Each version of the License is given a distinguishing version
number. If the Document specifies that a particular numbered
version of this License "or any later version" applies to it, you
have the option of following the terms and conditions either of
that specified version or of any later version that has been
published (not as a draft) by the Free Software Foundation. If
the Document does not specify a version number of this License,
you may choose any version ever published (not as a draft) by the
Free Software Foundation.
B.1.1 ADDENDUM: How to use this License for your documents
----------------------------------------------------------
To use this License in a document you have written, include a copy of
the License in the document and put the following copyright and license
notices just after the title page:
Copyright (C) YEAR YOUR NAME.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1
or any later version published by the Free Software Foundation;
with the Invariant Sections being LIST THEIR TITLES, with the
Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.
A copy of the license is included in the section entitled ``GNU
Free Documentation License''.
If you have no Invariant Sections, write "with no Invariant Sections"
instead of saying which ones are invariant. If you have no Front-Cover
Texts, write "no Front-Cover Texts" instead of "Front-Cover Texts being
LIST"; likewise for Back-Cover Texts.
If your document contains nontrivial examples of program code, we
recommend releasing these examples in parallel under your choice of
free software license, such as the GNU General Public License, to
permit their use in free software.
File: vamos.info, Node: Concept Index, Prev: Copying, Up: Top
Concept Index
*************
[index ]
* Menu:
* Atmosphere: The World Library. (line 44)
* Body: The Body Library. (line 6)
* body library: The Body Library. (line 6)
* building: Building Vamos. (line 6)
* Car: The Body Library. (line 6)
* cars: Cars. (line 6)
* compiling: Building Vamos. (line 38)
* configure: Building Vamos. (line 38)
* controls: Controls. (line 15)
* Conversions: The Geometry Library.
(line 106)
* copying: Copying. (line 6)
* dashboard: Dashboard. (line 6)
* dependencies: Building Vamos. (line 17)
* downloading: Building Vamos. (line 9)
* driving: Let's Go. (line 6)
* FDL, GNU Free Documentation License: Copying. (line 16)
* Frame: The Body Library. (line 6)
* geometry library: The Geometry Library.
(line 6)
* image: The Geometry Library.
(line 99)
* inertia tensor: The Geometry Library.
(line 57)
* Inertia_Tensor: The Geometry Library.
(line 57)
* installing: Building Vamos. (line 38)
* libvamos-body: The Body Library. (line 6)
* libvamos-geometry: The Geometry Library.
(line 6)
* libvamos-media: The Media Library. (line 6)
* libvamos-track: The Track Library. (line 6)
* libvamos-world: The World Library. (line 6)
* matrix: The Geometry Library.
(line 36)
* media library: The Media Library. (line 6)
* Particle: The Body Library. (line 6)
* point: The Geometry Library.
(line 66)
* spline: The Geometry Library.
(line 82)
* Spline: The Geometry Library.
(line 82)
* surface: The Geometry Library.
(line 93)
* texture: The Geometry Library.
(line 99)
* Texture_Image: The Geometry Library.
(line 99)
* Three_Matrix: The Geometry Library.
(line 36)
* Three_Vector: The Geometry Library.
(line 14)
* track library: The Track Library. (line 6)
* tracks: Tracks. (line 6)
* Two_Point: The Geometry Library.
(line 66)
* units: Units. (line 6)
* Vamos_Body: The Body Library. (line 6)
* Vamos_Geometry: The Geometry Library.
(line 6)
* Vamos_Media: The Media Library. (line 6)
* Vamos_Track: The Track Library. (line 6)
* Vamos_World: The World Library. (line 6)
* vector: The Geometry Library.
(line 14)
* world library: The World Library. (line 6)
Tag Table:
Node: Top1233
Node: Let's Go2301
Node: Controls4744
Node: Dashboard10700
Node: Cars12807
Node: Tracks24564
Node: Worlds37476
Node: Units38912
Node: Code Reference40765
Node: The Geometry Library43198
Node: The Media Library46667
Node: The Track Library46836
Node: The Body Library47883
Node: Frame48658
Node: Particle48759
Node: Body48879
Node: Car48989
Node: The World Library49152
Node: Building Vamos51001
Node: Copying53588
Node: Concept Index73815
End Tag Table