ACC files still necessary

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ACC files still necessary

Postby chad3006 » Fri Dec 30, 2016 7:10 pm

With the introduction of Open Scene Graph in Speed Dreams, is it still necessary to have the cars be converted to the .ACC format? Since the shading is handled by OSG, wouldn't a plain .AC file be OK? I think FlightGear shades the .AC files of planes, but I don't know if FlightGear uses OSG or not.
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Re: ACC files still necessary

Postby xDraconian » Sat Dec 31, 2016 9:29 am

FlightGear does use OSG. It has been a while since I looked at the ACCC code, but I seem to recall it performs some geometry optimization (e.g. tri-strips and tri-fans) in addition to the shadow and reflection stuff it does by adding support for multiple textures per object.
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Re: ACC files still necessary

Postby simon-2 » Sat Dec 31, 2016 1:50 pm

besides the multi texturing, acc also stores surface normals (which ac does not). Maybe, osg could calculate them at runtime (i think, most of the normals are auto-generated by sd2-accc), but this would eliminate the possibility to use "faked" (or "tuned") normals to pretend a detail or shape that would otherwise need much more polys (no idea in how far this actually used for SD cars).

Also, consider that SD is in a kind of transition phase- i.e. osg support is still in development and and does not include all the features that were implemented for plib/ssg. For me, ssg still offers a better gaming experience (though osg's advantages are already visible). So- why not keep them (and run sd2-accc for new content) as long as ssg is still used by some?
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Re: ACC files still necessary

Postby jjsca » Sun Jan 01, 2017 12:32 am

Hello chad,

I am not 100% sure of what I am going to tell you, but this was true some time ago and I don't think it changed since. Yes you need to convert your 3d models to acc to run them in OSG. In fact if I am not mistaken, it is in fact the only way to have it not to crash. In fact the acc file gets converted to osg format on the fly.

best Regards,

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Re: ACC files still necessary

Postby makza01 » Mon Apr 24, 2017 8:53 am

Thanks for the info

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Re: ACC files still necessary

Postby wanda01 » Tue Apr 25, 2017 9:04 am

It is very interesting.

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