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Russian Helicopter Mil Mi-6

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Russian Helicopter Mil Mi-6

Postby Blender3D » Fri Jun 19, 2009 1:04 pm

Hello, guys

As long as I learned to control them, I am a helicopter fan. And now I've tried to build a real big helicopter, the Russian Mil mi-6. But I still have some Problems. For example: When I put the Model and the *.xml File in their directory in the .../Airplanes directory, I can choose them from fgrun. And the model is shown as it should be in the preview display. But when I start the simulation the performance is __real__ slow. About 0.01 FPS. Why is that? It's impossible to use this helicopter like this.

i hope you have a solution.

--Blender3D

EDIT:
The current version of my helicopter, lots of improvements in the flight-behavior. Please comment!

EDIT2: Downloadlink invalid - I removed it.

EDIT3:
Newest version always available via GIT:
Code: Select all
git clone git://gitorious.org/mil-mi-6/mi6dev.git


EDIT4: new repository name solves theoretical naming issues.
Last edited by Blender3D on Sun Aug 29, 2010 3:17 pm, edited 5 times in total.
Fly one of the biggest rotary wing aircraft the world has seen so far! --> Get the newest version now! (http://gitorious.org/mil-mi-6/mi6dev/archive-tarball/master or "git clone git://gitorious.org/mil-mi-6/mi6dev.git")
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Re: Mil mi-6...

Postby Fahim Dalvi » Fri Jun 19, 2009 1:16 pm

Hi,

Well, There could be numerous things causing your problem. One could be that your model is very Heavy, i.e. It has a got a lot of polygons. Could you Upload it somewhere so we have a look at it?
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Re: Mil mi-6...

Postby Maerchenprinz » Fri Jun 19, 2009 2:15 pm

Hallo!

First off all I'd like to say that it's great to read that there is someone developing the Mi-6!
But this framerate...
Maybe you haven't yet made all objects in your model-file one-sided where necessary; or there are
still some polygones with a "bad" surface, meaning that e.g. a square surface has one vertex which
is not in the same plane (plain?) as the other three ones. This produces AFAIK a heavy load on your graphics card.

These are just first guesses; You should wait for replies from more experienced developers than me! :D

Anyway, if you like, you can send me your model.

Ciao,
Adrian
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Re: Mil mi-6...

Postby Blender3D » Fri Jun 19, 2009 3:40 pm

Ok... I've now compressed the current status of the helicopter: http://www.files.to/get/711369/xzqj8hrrf1

There are 6476 faces for the whole helicopter. It's a mixture between quads and triangles And yes not every quad is a flat surface. Should I convert all the quads into triangles before exporting the model? So that there are only triangles?
But then again: The preview window of fgrun does not have any problems with performance.

--Blender3D
Fly one of the biggest rotary wing aircraft the world has seen so far! --> Get the newest version now! (http://gitorious.org/mil-mi-6/mi6dev/archive-tarball/master or "git clone git://gitorious.org/mil-mi-6/mi6dev.git")
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Re: Mil mi-6...

Postby HHS » Fri Jun 19, 2009 4:01 pm

Blender3D wrote:Ok... I've now compressed the current status of the helicopter: http://www.files.to/get/711369/xzqj8hrrf1

There are 6476 faces for the whole helicopter. It's a mixture between quads and triangles And yes not every quad is a flat surface. Should I convert all the quads into triangles before exporting the model? So that there are only triangles?
But then again: The preview window of fgrun does not have any problems with performance.

--Blender3D


The number of faces or vertices is not important in SinglePlay. You can even have 1.000.000 vertices and have no fps-impact...

Your problem is: you didn't specify any fdm- so you don't have any contact points and the model falls trough the ground.Due to OSG and other things this means in this case a lot of errors and NaN-reports and with that a heavy loss of fps!
Specify first a simple fdm so you can look at your model in FGFS.
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Re: Mil mi-6...

Postby Blender3D » Fri Jun 19, 2009 4:16 pm

ok... But how do i specify a fdm?

--Blender3D
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Re: Mil mi-6...

Postby HHS » Fri Jun 19, 2009 4:25 pm

Blender3D wrote:ok... But how do i specify a fdm?

--Blender3D



For helicopter it is a bit more difficulter than for aircrafts.
First have a look into data/Docs/READMEyasim- it is the description of all parts of the YASDim-fdm.
Also have a look into other aircrafts. You can use a fdm from another aircraft. For this heli I would recommend the Superfrelon, AirCrane or CH53.

For getting a accurate fdm for he Mil mi-6 we would need empty mass; the location of fuel tanks, center of gravity, crew (positions of pilots etc...), datas about the rotor system, tensors, airfoil datas. A lot of them are still secret but for a first try not necessary.
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Re: Mil mi-6...

Postby Maerchenprinz » Fri Jun 19, 2009 4:32 pm

Hallo again!

Yeah, this looks really cool!
There are a few things that I noticed:
First of all, I don't get a framerate-"crash" when the model loads (when I use the ufo flightmodel).
Second, when I looked at the .xmls, I saw that they load the whole fuselage for four times I think (mi-6-left- ,mi-6-front- and mi-6-rightwheel.ac
consist all of the specific wheel PLUS the fuselage; Did you get a little bit confused during modelling? :) )
And third, you don't have to triangulate ALL surfaces, only those without a flat surface. Later, when your Mi will be committed, people with a
slow computer/graphics card will give you a hug for having done that! (And it looks much better!)

And fourth, here is my knowledge of how to make an fdm:
"empty log message"

Take a look at the Docs-folder in /data, there is a description of yasim, and e.g. the EC135 can give you a good example of how to do it.
EDIT: Just saw that Heiko already answered this. Ignore previous sentence :)

Ciao,
Adrian
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Re: Mil mi-6...

Postby yurik_nsk » Fri Jun 19, 2009 4:59 pm

There is a nice model of Mi-6:
http://www.airwar.ru/other/3m/mi6.html

Some time ago, author of it (Alex Emelianov aka DUST) write me and permit use it for FlightGear, but I was busy, and have no plans create model of helicopter.

If you want, you can take it and create nice model for FG.

There is a flight manual of Mi-6, and there are real pilots of this heli on avsim.ru. It's not a secret, all flight data is free...
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Re: Mil mi-6...

Postby HHS » Fri Jun 19, 2009 5:06 pm

yurik_nsk wrote:There is a nice model of Mi-6:
http://www.airwar.ru/other/3m/mi6.html

Some time ago, author of it (Alex Emelianov aka DUST) write me and permit use it for FlightGear, but I was busy, and have no plans create model of helicopter.

If you want, you can take it and create nice model for FG.

There is a flight manual of Mi-6, and there are real pilots of this heli on avsim.ru. It's not a secret, all flight data is free...


Nice news- I meant the aifoil datas and the tensors. The airfoil datas are important because we need the lift and drag curves- they determine a lot the flight behaviour of the helicopter. Simulating helis with yasim works different than airrcafts. Cruise speed etc. doesn't help much here....
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Re: Mil mi-6...

Postby Blender3D » Fri Jun 19, 2009 9:35 pm

@ yurik_nsk:
The model looks nice. But I want to use my own model. Maybe I'll take it later and put in into FG when I'm done with my own helicopter.

@Maerchenprinz:
No I didn't get confused. But I think my exporter is malfunctioning. I'll seperate the wheels from the fuselage tomorrow and I hope it fixes the performance problems.

@ all:
Thank you for your quick an useful answeres.
But I got another question: How do you specify any kind of texture mapping? Will they be saved in the *.ac file?

--Blender3D
Fly one of the biggest rotary wing aircraft the world has seen so far! --> Get the newest version now! (http://gitorious.org/mil-mi-6/mi6dev/archive-tarball/master or "git clone git://gitorious.org/mil-mi-6/mi6dev.git")
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Re: Mil mi-6...

Postby helijah » Sat Jun 20, 2009 8:50 am

Blender3D wrote:@ all:
Thank you for your quick an useful answeres.
But I got another question: How do you specify any kind of texture mapping? Will they be saved in the *.ac file?

--Blender3D


The textures are not included in the files .ac
We must start by achieving the UV Map in Blender, then create the appropriate texture.

Here is a tutorial that I started but never finished (sorry for the moment only in French)
http://helijah.free.fr/flightgear/Creation/UV-Map/uv-map-fr.html

Best regards. Emmanuel
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http://embaranger.free.fr
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Re: Mil mi-6...

Postby yurik_nsk » Sat Jun 20, 2009 9:57 am

The airfoil datas are important because we need the lift and drag curves- they determine a lot the flight behaviour of the helicopter.


All data, airfoils, Cx, Cy, a lot of details there are here: http://www.airwar.ru/other/bibl/mi-6to.html

But all in Russian, unfortunatelly...

Simulating helis with yasim works different than airrcafts.


I'm not know nothing about YASIM :) all my models use JSBSim...
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Re: Mil mi-6...

Postby Blender3D » Sat Jun 20, 2009 11:04 am

@ helijah:
You misunderstood me.... but it doesn't matter.

@ topic: I fixed the performance problems by copying everything from the S76C.xml into the mil_mi-6-yasim.xml.

--Blender3D
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Re: Mil mi-6...

Postby HHS » Sat Jun 20, 2009 3:34 pm

yurik_nsk wrote:
The airfoil datas are important because we need the lift and drag curves- they determine a lot the flight behaviour of the helicopter.


All data, airfoils, Cx, Cy, a lot of details there are here: http://www.airwar.ru/other/bibl/mi-6to.html

But all in Russian, unfortunatelly...



Oh :shock: But unfortunately in russian...
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