Speed Dreams Documentation Wiki

Artists Tools for Speed Dreams

3D

The source format for tracks and cars 3D data is an AC3D geometry data file *.ac. This source can be compiled by ACCC (AC3D compiler) to enable reflections and shadows.

AC3D
AC3D is a 3D design sofware which has been available since 1994. It is used by designers for modeling 3D graphics for games and simulations. AC3D is available under Linux, Mac OS X and Windows (but is unfortunately no more free).
Inivis Website

ACCC
ACCC is the AC3D compiler to convert files from the *.ac format to the *.acc format to enable reflections and shadows. ACCC is a command line utility that is shipped with Speed Dreams and is located at the Speed Dreams installation directory.
ACCC source

Blender
Blender is the free open source 3D content creation suite, available for all major operating systems under the GNU General Public License. Blender ships with a AC3D importer and exporter. Blender is available for Linux, Mac OS X and Windows.
Blender Foundation
Daily Blender tips & news
UV mapping tutorial

Blender ACC Importer/ Exporter
A Python script written by project member Brian Gavin to import or export *.acc files in/from Blender.
Speed Dreams Import/Exporter for Blender

Stripe
Stripe is required to triangulate any face of a track or car so it can be computed by ACCC. Stripe is a command line utility.
Stripe Website

Texturing & 2D Artwork

The source format for textures and 2D artwork are layered GIMP files (*.xcf or compressed *.xcf.bz2). At the game itself the PNG image format is prefered.

GIMP
GIMP is a free software raster graphics editor. It is primarily employed as an image retouching and editing tool, in addition to offering freeform drawing, GIMP can accomplish essential image workflow steps such as resizing, editing, and cropping photos, combining multiple images, and converting between different image formats.
GIMP website
GIMP screencasts

GIMP Plug-ins
There are a lot of useful 3D and texture plug-ins for GIMP. Check out the article "Pimp the GIMP for 3D" by team member Eckhard M. Jäger:
http://my.opera.com/area42/blog/pimp-the-gimp-for-3d

Inkscape
Inkscape is a vector graphics editor application. It is distributed under a free software license, the GNU GPL. Its stated goal is to become a powerful graphics tool while being fully compliant with the XML, SVG, and CSS standards.
Inkscape website
Inkscape Screencasts

OptiPNG
A nice cross platform command line utility to optimize/ reduce the size of PNG files up to 25%. Easy to use in a shell window inside a track folder: "optipng *.png".
OptiPNG - Advanced PNG Optimizer

Engine sounds

In Speed Dreams, engine sounds are produced through the !PLib or !OpenAL backend libraries (at the user's choice).
In each of these libs, the real-time engine sound is generated by applying a pitch coefficient to an "original" engine sound sample.
For each car, this "original" sample have to follow 3 strong rules :

• exist as a 16 bit integer format .wav file
• correspond to a constant and as stable as possible engine rate and audio power level
• feature a similar and symmetrical start and end : simply remember that the library will loop-playback the sample, and you probably don't want to hear any change at the end of each loop ;-)

QATSH
A way to produce such samples is to grab some real-life on-board sound sampled records for the car you target ...
Unfortunately, these real life samples rarely feature the 2 last constraints, as the engine speed is always changing !

QATSH is a full C++/Qt4 rewrite of the GUI of the Windows version of ATSH (an Analysis Transformation Synthesis Shell by Oscar Pablo Di Liscia, Juan Pampin and Pete Moss). The ATSA spectral analysis library behind has been slightly restructured (now independant from the sound sample I/O library) and the synthesis algorithm was improved a bit.

With QATSH, you basically :

• open a mono-phonic sample file (many formats supported),
• run a spectral analysis to separate the "partials" (the signal = the engine spectra ...) from the "residual" (the noise),
• modify the partials and residual through direct edition or by applying multi-dimensional formulas,
• synthesize a new sound from the modified partials and residual,
• play (and save if you like it) the resulting sound.

QATSH if currently under development, but is already working as explained above, under Windows and Linux.
It will be soon released under GPL2+ license, in the Speed Dreams Subversion repository (probably /subprojects/qatsh).

Planned features :

• new ARMA spectral analysis algorithm, for better accuracy of the partials,
• new instant spectrum view (amplitude of all partials at a given time in the samples),
• direct edition of the magnitude, frequency and Signal to Mask Ratio (SMR) of any partial at any time,
• direct edition of the energy (SMR) of any residual band at any time,
• ...