Es/FlightGear Newsletter March 2011
|This article is currently being translated.|
Nos gustaría hacer hincapié en que el boletín mensual no puede vivir sin las contribuciones de los usuarios y desarrolladores de FlightGear. Todo el mundo con una cuenta en el wiki (registrarse es gratuito) puede editar el boletín de noticias y toda contribución es bienvenida. Por tanto si sabes de algún proyecto relacionado con FlightGear, como por ejemplo un escenario o una aeronave actualizada, por favor sientete invitado a añadir este tipo de noticias en el boletín.
Local Weather v1.0
After more than a year of development work, the Local Weather package has reached its full design functionality as described in A local weather system and is available for download as version 1.0. The package works with Flightgear 2.0.0 and higher, though some extensions (marked with [GIT]) require a more recent binary.
Version 1.0 offers the following features:
- numerous types of clouds from Cirrus to Cumulonimbus, arranged in realistic patterns and size distributions, visible up to 80 km distance
- weather phenomena tied to location: rain only underneath clouds, dense clouds obscure sunlight [GIT], convective clouds develop according to terrain
- spatial interpolation of weather parameters like pressure, temperature, visibility, wind
- effect volumes controlling short-range turbulence, rain, snow, visibility and shadow [GIT]
- terrain-dependent modeling of boundary layer winds, gusts and turbulence
- complete offline weather system involving different airmass types and weather fronts
- integration of online METAR data [GIT]
- full support for soaring [GIT], thermals are automatically generated by the convective system
- optional dynamics: clouds drift in the wind, convective clouds are generated and decay, properties of thermals evolve in time
- backward compatibility to Flightgear 2.0.0
A feature gallery:
- lines of Nasal code: 10135
- estimated coffee consumption during coding: 120 L
- estimated time spent watching and photographing the sky: 50 h
New software tools and projects
Modeling a UAV with FlightGear and YASim
FlightGear can be a great tool for aerospace engineering. Here is an example of using the YASim physics engine in FlightGear to model a real world UAV based on the actual mass and geometry and performance of the airframe. There is a Blender plugin that can be used to visualize and validate the geometric data of the model. Once the simulation model is tuned and flying well, FlightGear can be used to do do simple design variation tests and predict how those changes will affect the stability of the design.
For more information: Using FlightGear + YASim to model and test real world UAV
In the hangar
A new TCAS instrument is available in the latest GIT version of FlightGear. The TCAS works with AI and multiplayer aircraft, provides aural warnings for conflicting traffic and is also capable of driving a realistic traffic display. AI aircraft also respond to TCAS alerts and take evasive action - meaning you can trigger some basic interaction with AI aircraft.
Lockheed Model L.10 "Electra"
Emilian Huminiuc has continued working on the "Electra" (the plane with wich Amelia Earhart atempted her round the world flight). So far the exterior is almost complete. There are separate texture sheets for the fuselage and wings, engine cowlings, and gear and miscelanea appendages. Also, after testing with .dds textures, these will be the kind used due to improved loading time and better normal map support. Work is going on, focusing on the interior now, with a basic cabin model already in place. What folows is the hardest part: cockpit modeling, complete with period steam gauges.
Normalmap detail visible
A new glider, the DG-101G from Glaser-Dirks, has been added to Git. It utilizes a JSBSim FDM, tuned with data calculated with XFLR5. This model features winch start, aerotowing, a drag robot, water ballast and livery over MP.
Work on the BK117 helicopter has been started. The BK117 is a twin-engined medium utility–transport helicopter, produced in a coproduction between MBB/Eurocopter and Kawasaki. It uses the same rigid rotor system like Bo105, but is larger in size and has more power. It is quite common in the world and very often used by emergency services and law enforcements.
The model features a realistic FlightDynamicModel based and calculated from NASA-reports, a detailed 3d-model with normalmap and reflection shaders, detailed rotor (thanks to Melchior!) and will be dynamically configurable in many variants. It is planned to make it realistic as it can be and good or even better than the Ec130 B4.
Next steps are the interior modeling with a detailed 3d-cockpit. Please follow the process in the forum.
Work on the Hawker Tempest continues but painfully slowly:
- Flight Dynamic Model: there is contemporary performance data  and detailed dimensions available, but no aerodynamic data. This is what YASim was intended for. However, it turns out that YASim does not like high powered, high performance propellor aircraft. When fed realistic data YASim produces a near supersonic solution. However, testing and tuning over 2 weeks has produced an output which closely matches the published data, even if the input data look somewhat bizarre. The Tempest could approach the compressibilty region in a dive. Its operating handbook specifically limited its performance envelope to avoid this, but it might be a useful future extension to add a bit of transonic drag.
- Texture: nearly finished, but made more difficult by the decision to put all external textures on one 1024 x 1024 sheet. This has the advantage of making a reflection map easier to produce, but aligning all the camoflage joins is ... a nightmare. Tests have been carried out with .dds, .png, and .rgb files: there seems little to chose between them in appearance terms. An executive decision-making aid will be used later (AKA toss of a coin).
- 3D Cockpit: largely a rework of the Hawker Hurricane cockpit (as it was in real life). About 50% complete.
Overall, we are looking at three months more work.
LZ 121 Nordstern
The Zeppelin LZ 121 Nordstern has been updated with a new gas and ballast control board by Anders.
Chris (papillon81) took care of the Concorde's TCAS and converted it to the new generic system by ThorstenB. The old Concorde-specific one was implemented using Nasal and xml and Thorsten got rid of about 1800 LOC in the process. He also created a new glass instrument (the only one in the Concorde's cockpit), modeled according to some web sources. The new system works with both AI and multiplayer traffic.
Livery database reaches 400
This month the FlightGear livery database welcomed its 400th livery! A big thank you to all those artists that contributed over the past two years. A special thank you is justified for gooneybird, who saw his 150th livery commited this month, making him by far the top-contributer!
One of world's most famous landmarks, the Taj Mahal in India, is now modeled and included in the scenery database. Dubai also welcomed a new model, the famous hotel Burj al Arab.
A bunch of new Asian buildings is added, including:
- Two International Finance Centre - Hong Kong - China
- International Commerce Center - Hong Kong - China
- Shanghai World Finance Center - Shanghai - China
- Jin Mao Tower - Shanghai - China
- Oriental Pearl Tower - Shanghai - China
- Tuntex Sky Tower - Kaohsiung - Taïwan
- Northeast Asia Trade Tower - Incheon - South Korea
- 63 Building - Seoul - South Korea
- N Seoul Tower - Seoul - South Korea
Full scale 747 simulator
As you might know, John Wojnaroski has been working for several years on a full-scale 747 simulator, powered by FlightGear. Recently he published two videos, showing the current status of the sim. Recent developments were focused on a panoramic display.
The projectors are (3) short throw 1200x800 native resolution units, mounted on the ceiling. Each projector is first mechanically aligned using the projector test pattern. Next a warping mesh based on projector location and screen dimensions is created and a test pattern using the mesh is produced by FlightGear. The warping mesh is then adjusted to tune the resultant image thrown on the screen as well as mechanical adjustments. And as a final step the "production" image is adjusted by setting the viewing heading for the side projectors for horizontal alignment and projector internals and mesh recalculations for the vertical as required.
The image warping software is contained in the CameraGroup.cxx based on the OSG code for a spherical panoramic display. Tim Moore adapted the source to run with the FlightGear camera group and I extended it to display a warping mesh for a cylindrical panoramic display. There is a stand alone utility to create a mesh warping file that can be tailored for each projector and is loaded at FG init time.
The edge blending is accomplished using gray scale polygons as textures. Further refinement is required to adjust the gamma function to handle pixel brightness based on RGB color values. The slight image flickering is an artifact of the projector and video camera sync mismatches and not observable by the human eye. The videos don't really capture the immersive quality of the wrap-around screen or sensation of motion.
The FG hosting machine is a quad-core Intel I5 with 4GB memory and three nVidia 9400GT graphics. Running FG on a single core produces a frame rate of 28fps using SDL and around 30fps with glut-3.7 with 3D clouds enabled. A higher frame rate of 60-65fps is possible running three instances of fgfs on each core and using the internal localhost socket; however you lose the ability to sync features such as AI traffic, clouds, or multiplayer aircraft.
Airport of the month
Martin State Airport (KMTN) north of Baltimore, Maryland may be the best airport in FlightGear you've never heard of.
Make sure you have the object file downloaded, and if you don't have the Baltimore/Washington custom scenery, head over and download the terrain from statto's FlightGear website. Install this properly and you are set to have a quality VFR flight experience!
To start out do a touch-and-go on runway 31. Start your turn over the pattern near the Anne Arundel Mall (a big asphalt blob in the middle of the farmland), then come in over the handcrafted terrain of the harbor.
For a cross-country flight, fly down Baltimore Harbor toward the well-modeled Baltimore-Washington Int'l Airport, then follow the railway and freeway past College Park. Overfly RFK Stadium and the Washington National Mall before turning and landing at Washington National Airport (KDCA).
The custom models combined with the custom scenery really sets this part of the world apart from the default areas in FlightGear - have a flight over Maryland today!
FlightGear on YouTube
And finally ...
One of the regular thoughts expressed on the FlightGear forums is "I'd like to contribute but I don't know how to program, and I don't have the time". Unfortunately, there is a common mis-conception that contributing requires programming and lots of free time. In fact, there are a huge range of ways to contribute to the project without needing to write code or spending days working on something.
For ideas on starting to contribute to FlightGear, you may want to check out: Volunteer.