3D%20graphics%20in%20Erlang

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3D graphics in Erlang

• Jakob Cederlund - jakob_at_gnodata.se
• Björn Gustavsson - bjorn_at_erix.ericsson.se
• Dan Gudmundsson - dgud_at_erix.ericsson.se

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3D graphics in erlang

• 3D graphics with hardware acceleration
• OpenGL - an open version of SGIs GL
• Reasonable API
• Open standard
• Cross platform (Wintel, Linux, Sun, Mac)
• Widespread support from hardware
• SDL - a library supplementing OpenGL with
  interaction, 2D graphics and more

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erlang and 3D graphics

• erlang high level language
• 3D graphics needs symbolic language
• Fast development
• Performance critical code mostly in 3D hardware
  and drivers

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ESDL

• An erlang driver that interfaces with SDL
• Supports most OpenGL calls
• Fast
• Optimized C driver
• Uses binary syntax
• Available as download from contrib area
• Written by Dan Gudmundsson

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ESDL
erlang
3D program
esdl-driver
esdl
SDL lib
OpenGL
3D hardware
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Wings - a 3D modeller in erlang

• Uses erlang as functional language
• Fast development
• Good performance
• Powerful
• Innovative user interface
• Inspired by Nendo
• Written by Björn Gustavsson
• Some inspiration from Jakob Cederlund

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Wings

• Most of the erlang code not performance critical
• Some functions optimized
• Winged-edge structure for 3D objects
• Uses gb_trees and gb_sets (included in OTP R8)

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Wings - features

• Powerful modelling
• Every operation applicable to several objects at
  the same time
• Imports and exports to different formats
• Wavefront
• 3D studio
• Easy to do easy things
• As opposed to other 3D modellers

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Wings - development

• Functional
• Only one process
• Process dictionary used in for GUI state
• Some things suprisingly easy to do
• Multiple undo, with shared data
• Only updates appriopriate parts of the model
• Continues after crash, e.g. to save work
• Just a catch, saves dump to file
• Library functions used
• gb_sets and gb_trees (R8)
• sofs - Sets OF Sets (R8)
• digraph and digraph_utils

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Wings - development cont.

• Funs used a lot
• special fold operations to iterate over model
  elements
• Optimization after implementation and testing
• Data structures hidden, used via functions
• Most user commands uses primitive commands
• Example inset
• Extrude
• Scale

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Wings - examples

• Rendered in Bryce, composited in PhotoShop

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Wings - examples cont.

• Modelled in only 5 minutes!
• Rendered afterwards in Bryce

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Wings - performance

• Most things fast enough
• Optimized floating point in R8
• Some things take time
• Smooth
• Dissolve
• Used as primitive by many commands
• erlang fast enough, even for interactive tasks

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Wings - future

• Long to-do list
• Ongoing development, bugfixing and new features
• Future features
• Plug-ins, both in erlang and C
• More export formats, e.g. renderman
• Cameras, multiple views
• Materials, textures
• New platforms (MacOSX)

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Wings - availability

• Open source
• Full source on sourceforge
• Compiled versions
• Currently requires otp, esdl and SDL
• Stand-alone erlang version with installer will be
  available shortly
• Documentation and examples
• Home page http//www.erlang.org/project/wings/