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Startup from the scratch with Openflight

Original Post by: Philskills Thu Aug 25 10:18:04 2011

Hello all!

I am new to this forum as well as to Openflight, please be patient with me ;-)

I work for an Flight Simulation Training Organisation in Austria, we operate a Fokker 100 Level D Flight Simulator and now we started to create sceneries ourselves with a modelling tool from our Vision System supplier. The problem is that we have had no experience with Openflight before, so we start now from the very beginning.

My first issue is that we received Source files for our next scenery in the gmax-format. We have to convert them into openflight to use them in our database. This is possible with free tools, such as Blender or ModelConverterX. The problem is just that I am not confident with the information that is saved in the Openflight file.

When I add the .flt file to the scenery, it does not get textured - it always remains white. How do I connect the external rgb-textures to the flt-model. Is that info saved in the rgb.attr?

Thank you for your patience


Original Post by: ChrisRogers Thu Aug 25 15:25:38 2011

Hi Philskills,

Welcome to the forums! OpenFlight stores textures references inside of the .flt file in a palette. (This is just a list of textures that the file uses.) Then any geometry that uses textures identifies what texture in the palette it uses with an index. So the flt file could have a list of say 6 textures in the palette, and each piece of geometry would say I use texture 3 or whatever texture they really use. The attr file you mentioned is responsible for attributes about the textures. Things like if it should have mip maps, if it is filtered when rendered near/far etc…

As to why your polygons might be displaying un-textured, it is hard to say for sure. It could be that the converter you used does not support textures. It could also be that the textures cannot be found. The OpenFlight file is capable of representing textures in three important ways: absolute paths, relative paths and no paths. If you have a copy of Creator, you can inspect the state of the flt file and see how the paths are set up by the converter.

Original Post by: Philskills Fri Aug 26 07:04:12 2011

Hi Chris, thanks for your fast help!

It is good to know that the attr file is responsible for mip-maps, because I was asked in Photoshop wether I want to keep or delete them.

Thing is in my converter program (ModelConverterX) there is no option about paths... Could you recommend me a good Openflight converter that converts standard file types? It is not easy to find such a converter.. Is there any payware just to convert Openflight?

Thank you!


Original Post by: ChrisRogers Fri Aug 26 16:06:28 2011

Unfortunately you are not likely to find a good path from gmax to any other standard format. This is because gmax is designed as a closed format. Anyone who wants to import gmax format is required to pay large fees for such a privilege.

Here is a quote from the product manager for gmax from back in 2001

“gmax was designed to provide game developers and game enthusiasts a stable and robust 3d content creation and editing tool for Discreet approved game title formats. Discreet licenses (for a fee) to game companies the right to distribute gmax game packs. By design, this is the only means by which users are allowed to export data from gmax. Discreet withheld the ability to export data directly from gmax for many reasons, and we take very seriously any effort to defeat our design.”

This is one of the reasons why OpenFlight is so well received in the industry. We are an open format that means we freely provide the complete specification for our format and encourage people to write their own importers and exporters.

I would try to contact your supplier and ask for a different format.

Original Post by: Lars Fri Aug 26 17:17:53 2011

Creator does import a good variety of 3D formats, however. I often recommend .dae (Collada) as an interchange format. My suggestion is to get back to your source and ask them for another format, Creator can ingest: 3ds, obj, dxf, dae.

Does your simulator use the gmax format at all? It seems curious to me that you would be delivered a proprietary and closed format as source.

Original Post by: Philskills Sun Aug 28 07:09:15 2011

Thanks for the information guys, this is very helpful.

No our simulator uses "Multi-Gen Openflight" which is as far as I know the old name of Openflight, today this format is owned by Presagis?

The only reason we got gmax and max-source is because we would like to use sceneries which were already developed for Microsoft Flight Simulator (FSX and FS9) from a supplier that releases Sceneries for Microsoft Flight Simulator and distributes them for professional Sims.

The problem is that I have no experience with Openflight at all. We had a training at our vision system supplier (Equipe Simulations) but we did not learn how to deal with Openflight files..

The only thing in the manual that is described are different LOD groups in the flt-file and that textures are specified in the file (their location).


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