Posts by brunnerant

Hello !

I have developed a small hangglider model a while ago and I would be interested to publish it in some way to ease its distribution.

Is there a tool to help developers publish aircrafts and help people install them ? And do you know websites where aircrafts might be published ?

Thanks for your pointers and happy flying !

Antoine Brunner

Hello guys !

I have been working on this hangglider model for quite some time now with my hangglider instructor. I have worked on the creation of the aircraft definition for the hangglider using the Aerofly SDK. In the meantime, my instructor has developped a harness to which we can hang, and that is linked to a joystick so that we can really immerse ourselves in the hanggliding simulation with the VR headset:

We have tested this setup and after a some adjustments, it is now working really good ! We presented this simulator to the Swiss hanggliding federation, because we would like to include this in hanggliding schools to encourage beginners (including myself ) to start hanggliding.

But before starting to use this simulator with other people, we would like to know what you think about selling it as a whole to other hanggliding schools, since the Aerofly simulator would be included in it. Are we authorized to do so ? Or is there some special license that we should buy to you in order to distribute Aerofly in the hanggliding simulator ?

I have no idea how this works, so if you know more about this, I'm glad to hear from you !

Thank you for your help, and happy flying (virtually or physically) !

Antoine Brunner

Thank you so much for your quick response !! Now I know what those mean, that should make my life so much more easier !

Well, I also wished the day had more hours, no worries on that side ! The forums act as some kind of documentation anyway, as long as the info is somewhere...

Thank you once more !

Hello,

I am developing a custom plane (a hangdlider -_-) for Aerofly, and I am now trying to add some virtual controls it, so that virtual reality works. However, unlike traditional airplanes that have a stick to control the aircraft, hanggliders have a bar, which is horizontal and held by the pilot with two hands. I started to fiddle with control_cylinder in the file controls.tmd, but I am now stuck because I couldn't really figure out what are all the parameters that it takes.

Could someone explain how control cylinder works in more details (I couldn't find the necessary details in the documentation unfortunately):

• How does B0 work ? I understand that it is the transform of the cylinder, but then in what direction is the cylinder when B0 is the identity ?
• What are Direction and Direction2 ? If B0 already handles the orientation of the cylinder, then why are those two needed ? Are theyused to give the two axes along which the virtual stick can be moved ?

• To simulate the bar of the hangglider, I have set the type of the cylinder to "stick" (i.e. <[string8][Type][stick]>). Is there something else that would be more appropriate in my case ? And what does that exactly mean ?

That's a lot of questions, but I really want to bang my head at the wall trying to understand how all those config files work without a precise documentation. Also, the controls cannot be easily visualized or debugged within Aerofly, so it is really hard to know what are the effects of my changes in the TMD file...

Anyway, I would be very grateful if anyone could shed some light on those mysteries :)...

Cheers,

Antoine Brunner

Hello guys !

I am making some good progress with the hangglider, it is now flyable ! I have tried to reduce the wing span a little bit (not in the graphical part yet), and it is way more controllable !

I have a few more questions that I couldn't find an answer myself:

• I have added some wheels to the glider so that it can actually land. I have added them at both sides of the speedbar, like it is usually done, and it works great. For the other critical spots of the glider (like the tail of the keel and the wing tips), I have tried to add collision_spheres. Unfortunately, it doesn't seem to work, since they were able to traverse the ground. I would ideally like them to act like in real life, where they would scrape the ground and slow the glider down. Since it didn't work that way, I have for now replaced the collision_spheres by wheels (which works, but the glider doesn't slow down when touching the ground).
• I would now like to allow the speedbar to be grabbed with the mouse or with the VR hands. The speedbar should be translated in two axes (left-right or front-back) to actuate the glider. I have read the documentation about the different virtual controls, but I am not sure that any of them would fit. control_cylinder seems to be the closest fit, but I don't think that it can be used for translational controls, am I right ? If anyone knows about a potential solution, it is very welcomed !

Other than that, I hope that you are doing great ! I personally have some days off, so I can be a bit more productive working on the virtual glider . Unfortunately, though, the weather and the Covid do not allow me to fly my real paraglider, so I guess I'll have to wait ...

Cheers !

Antoine

Regarding the slow rolling, I think that it might be ok. I have never flown a hangglider, but I fly a paraglider, so I occasionally fly with some hanggliders. I think that the hanggliders that I have flown with had where more beginner-friendly ones. That means that they have a way smaller wingspan, which probably means that they're easier to roll (that seems intuitive to me, but I don't know if that intuition transfers to reality ). Also, beginner hanggliders are lighter than other ones (since pro hanggliders have a solid leading edge, as opposed to just tubes and fabric), meaning that the pilot-to-glider ratio is higher, so when the pilot moves, it has more impact on the center of gravity of the whole system.

Anyway, I will try to tweak the masses a little bit, to adjust the pilot-to-glider ratio, and see if that changes something. Regarding the horizontal position of the center of gravity, I will keep adjusting it until it feels stable.

I am happy to read your post larrylynx , and to see that I am not the only one having a hard time understanding TMD files (even though I have some solid geometry and math background). Maybe there should be a course "MA-101 - writing TMD files" at university .

I will keep you updated about the progress that I managed to make, but don't be disappointed if it isn't soon, because I am very busy at university right now .

Antoine

Hello !

I hope you're still doing fine in this weird 2020 . I finally had some time to work on the project, and I made some progress, so I wanted to give you some signs of life !

I used your aerodynamic calculations, ussiowa, and they are quite good, even though there are probably some things that we could improve. Now the hangglider is flyable, and it can be controlled using only mass transfer. Here is what I have noticed, and what I should improve:

• The computation for the CG and the MAC seem to give a pretty "tail
  heavy" behavior, where the glider has a tendency to pitch up. I have tried to move the pilot forward and it gave some better results (I moved it about 50cm forward, which is a lot!). Maybe that behavior could be coming from the aerodynamic of the wing as well.
• The hangglider seems to roll pretty slowly (pitch is fine however). It
  takes about around 5 seconds to roll to a 45° angle with the pilot leaning to the right pretty heavily. That might be caused by the pretty big wingspan. Beginner gliders have a smaller wingspan as well, so that's maybe the reason why. And additionaly, some gliders have elevators as well, so I will try to add some elevators to see if the behavior is better.
• I have added a vertical stabilizer to the glider (which is invisible) to prevent it from "sliding". Without that stabilizer, the glider is uncontrollable, starts turning in all sorts of directions, and it seems to be because of that "sliding". With the stabilizer, the glider is now very stable (and it could be another reason for the slow rolling).
• Moving the pilot around makes the glider "jiggle". I added a "servoclassic" with the speed set to "2.0" to smooth out the pilot movement and try to mitigate that problem. It is better, but still present. I think this is due to how the rigid body system works, where the impulses that are applied to the bodies are causing those jerks.

Thank you all for your responces, and sorry for the delay, I am pretty busy these days ;)...

Quote from Jet-Pack (IPACS)

Yes of course it is

That's some good news ;), it means that there is an error coming from my side. For now I have animated the graphics and the physics separately, so that's probably a bad pattern according to your answers. This also explains why I see the graphics moving but no behavior change. I will make sure that the graphics follow the physics, so that I can be convinced that the masses are actually moving.

Quote from ussiowa

OK so MAC (Main Aerodynamic Chord) is at 215.86 cm from center line and is 142.20 cm.

That means that the Aerodynamic Center (AC) for that wing is at 131.58 cm from the nose of the wing (25%).

Antoine that should be the starting point for the CG of the empty glider. I would expect that the CG point for all together in flight be around 125.4 cm from the nose and in the horizontal plane (20% of MAC or a 5% static margin).

These should be good numbers to start and should provide a flyable system. We can fine tune later.

The vertical position of the CG is whatever it is vertically from that point (125.4 from the nose, center line)

Thank you very much for your calculations, you rock !! I didn't have time to dig into your results, but I will definitely use your values to position the pilot relative to the wing.

Again, thank you guys so much for your involvment

Antoine

Okay guys, some updates, since I had time to test the new airfoils that ussiowa gave me.

First, I had to tweak the CG so that the flying is stable (like in your story, I have experimented, and I didn't rely on theory ). After some tweaking, I was able to observe some stable flying behavior. However, I couldn't experiment much, since I somehow wasn't able to steer the glider.

I hooked up the pitch and roll input from the simulator to a linear joint, and to the graphics. The graphical part works, because when I steer the glider, I actually see the pilot's graphics pitching/rolling. However, I am dubious that the linear joint is working because steering doesn't have an effect on the flying behavior... So I have to fix this...

Does anyone know if there is a way to debug the rigidbodies while in the simulator ? I would really like to be able to verify that the pilot's rigidbody pitches/rolls when I control the plane in the simulator.

Anyway, thank you guys for your involvment in the project !

Antoine

Yes, I have put the tag:

<[bool][Glider][true]>

Even though I am not sure of what it does

Hello ussiowa !

Thank you for your message ! I don't have a lot of time those days since I am doing a master in computer science, but I try to work on the hangglider in my free time.

I was thinking that you probably have the knowledge to help me with the dynamics of the hangglider, because I encounter some stability issues. The hangglider is stuck in a stall behaviour where it constantly rotates forward or backward, I guess that I may need to tweak the horizontal position of the pilot, so that the load on the wing is more stable. Also, I think it has to do with the fact that the initial speed of the glider is too slow, so it doesn't glide at all, but rather falls straight from the start.

If you want to know more about that project, you can send me an email at brunnerant@gmail.com and I will be happy to discuss in more depth about it ;).

Thank you so much for the interest, I really appreciate !

Antoine

Thank you guys for your help, I really appreciate it !

I have done what you said and started from a working file. I have taken the template.tmd file from the aircraft workshop, added my geometries, and added the aerowing definition from the asg29 glider. It doesn't crash anymore, which is some good progress ! However the dynamics are very unstable, so I will have to tweak it that so that the hangglider is actually flyable...

For the flight dynamics, I thought about controlling the hangglider using weightshift, so that it is as realistic as possible. The setup I thought of is having a rigidbody (the pilot) connected below the fuselage through a linearjoint which can be actuated by the player. I am not sure whether this is going to work, since nobody really did that before. Anyway, I will experiment, and who knows, maybe it's gonna work.

I attached some screenshots of my model (to tease you ), which I am very proud of. I have made it myself using Blender and GIMP, but I haven't added specular and reflection maps yet.

I will keep you updated if I manage to make some progress. Cheers !

Antoine

Hello,

First, let me tell you that an actual issue was that I was putting an empty line at the beginning of the TMD file, causing the aircraft converter to crash... The parser for the TMD file is definitely very brittle (and not talkative, which is even worse for the aircraft developers, but anyway, let's not get distracted). But unfortunately, once one error is solved the next stupid error shows up (that seems to be a constant in the world of computer science).

Here is the minimal TMD file that I am trying to get through :

<[file][][]
    <[modelmanager][][]
        <[pointer_list_tmuniverse][DynamicObjects][]
            <[rigidbody][Fuselage][]
                <[float64][Mass][10.0]>
                <[tmvector3d][InertiaLength][ 1.660000 0.560000 0.250000 ]>
                <[tmvector3d][R0][ 0.322017 0.000000 -0.006257 ]>
                <[tmmatrix3d][B0][ 0.996257 0.000000 -0.086444 0.000000 1.000000 0.000000 0.086444 0.000000 0.996257 ]>
            >
            <[rigidbody][LeftWing][]
                <[float64][Mass][10.0]>
                <[tmvector3d][InertiaLength][ 1.200000 5.000000 0.200000 ]>
                <[tmvector3d][R0][ -0.400000 2.300000 -0.035998 ]>
                <[tmmatrix3d][B0][ 0.733648 -0.398506 -0.013916 0.318999 0.916501 0.032005 0.000000 -0.034899 0.999391 ]>
            >
            <[rigidbody][RightWing][]
                <[float64][Mass][10.0]>
                <[tmvector3d][InertiaLength][ 1.200000 5.000000 0.200000 ]>
                <[tmvector3d][R0][ -0.400000 -2.300000 -0.035998 ]>
                <[tmmatrix3d][B0][ 0.733648 0.398506 -0.013916 -0.318999 0.916501 -0.032005 0.000000 0.034899 0.999391 ]>
            >
            <[multibody_joint][JointFuselageLeftWing][]
                <[string8][Body0][Fuselage]>
                <[string8][Body1][LeftWing]>
                <[tmvector3d][X0][ 1.0 0.0 0.0 ]>
                <[tmvector3d][R0][ 0.4 0.2 0.0 ]>
                <[float64][Kp][1000000.0]>
                <[float64][Kd][10000.0]>
                <[uint32][Type][0]>
            >
            <[multibody_joint][JointFuselageRightWing][]
                <[string8][Body0][Fuselage]>
                <[string8][Body1][RightWing]>
                <[tmvector3d][X0][ 1.0 0.0 0.0 ]>
                <[tmvector3d][R0][ 0.4 -0.2 0.0 ]>
                <[float64][Kp][1000000.0]>
                <[float64][Kd][10000.0]>
                <[uint32][Type][0]>
            >
            <[telemetry][Telemetry][]
                <[string8][Body][Fuselage]>
            >
            <[event_value][DEV0][]>
        >
        <[pointer_list_tmgraphics][GraphicObjects][]
            <[rigidbodygraphics][HangGliderGraphics][]
                <[uint32][PositionID][Fuselage.R]>
                <[uint32][OrientationID][Fuselage.Q]>
                <[string8][GeometryList][ Wing SpeedBar Cables Keel ]>
            >
        >
        <[pointer_list_tmsound][SoundObjects][]>
    >
>

Now, when I use the aircraft converter, I get an "unreferenced geometry Wing, SpeedBar, Cables and Keel", even though they're referenced in the TMD file, so I don't understand the problem here. When I open it in FS2, the preview is empty, and the game freezes during the loading screen.

I really have no idea why all those things happen to me, even though I have read all the documentation very carefully, and several times... I feel very stupid now, because this aircraft converter has driven me crazy ;)...

Cheers,

Antoine

Thank you so much for your help !

I will look into your suggestions and in case it really doesn't work I can post the full TMD file. Note that in the excerpt I posted, I have purposedly omitted the "<[file][][]>" and "<[modelmanager][][]>" tags.

Cheers,

Antoine

It is very weird, it still doesn't work... I have commented everything in my TMD file, except for the following :

<[pointer_list_tmuniverse][DynamicObjects][]
    <[rigidbody][Fuselage][]
        <[float64][Mass][]>
        <[tmvector3d][InertiaLength][ 1.660000 0.560000 0.250000 ]>
        <[tmvector3d][R0][ 0.322017 0.000000 -0.006257 ]>
        <[tmmatrix3d][B0][ 0.996257 0.000000 -0.086444 0.000000 1.000000 0.000000 0.086444 0.000000 0.996257 ]>
    >
    
    <[camera][FollowCamera][]
        <[string8][Body][Fuselage]>
        <[tmvector3d][R0][ -7.740298 0.000000 1.135027 ]>
        <[tmvector3d][Direction][ 0.975923 0.000000 -0.218117 ]>
    >
    <[camera][PilotCamera][]
        <[string8][Body][Fuselage]>
        <[tmvector3d][R0][ -0.401029 0.000000 -0.634648 ]>
        <[tmvector3d][Direction][ 0.766881 0.000000 -0.641789 ]>
        <[bool][InCockpit][true]>
    >
    
    <[telemetry][Telemetry][]
        <[string8][Body][Fuselage]>
        <[tmvector3d][LookAtPosition][ 0.0 0.0 0.0 ]>
        <[bool][CompensatedVariometer][false]>
    >
>
<[pointer_list_tmgraphics][GraphicObjects][]
    <[rigidbodygraphics][Hangglider][]
        <[uint32][PositionID][Fuselage.R]>
        <[uint32][OrientationID][Fuselage.Q]>
        <[string8][GeometryList][ Wing SpeedBar Cables Keel ]>
    >
>

I had to keep the telemetry section, because for some unknown reason, removing it makes the simulator crash at startup... As you can see, there is only one rigid body, and no joints, so I don't see what could be the problem here. But still, the simulator freezes and I cannot move the mouse cursor anymore.

I am really helpless right now, and I am starting to question whether I am extremely stupid or not...

Ok, I will definitely look into that, thank you for the insight !

Some of my rigid bodies overlap, but that's fine, according to the tutorial. Maybe it has to do with some incorrect joints, as you say, so I will try to search.

Quote from Jet-Pack (IPACS)

Are you able to fly or is it constantly resetting you to the runway?

Nothing moves, nor the mouse cursor. But the log file doesn't say anything...

Quote from stratospheric

Does your frame rate improve if you deactivate Vulkan?

I checked the settings, and the game uses OpenGL for the rendering.

Hello,

Again, I encounter some problems in the development of my custom aircraft. I have a 3D model which is comfortably in the poly-count limits (around 35K faces). However, when I open it in the simulator, it is incredibly laggy... I have found out that the reflections are costly, so I have disabled the reflections alltogether in the 3D model, but it still doesn't solve the issue. Also, the TMD file of the aircraft is still pretty simple, and I don't see why this would be the cause...

If anyone knows what could be the source of the lag, I would appreciate ;).

Happy flying !

Antoine Brunner

Hello,

I am making progress making my own hangglider model in Aerofly. However, I find it more and more difficult to debug errors because of the lack of documentation about the aircraft SDK. The begginning is very well guided by the tutorials, but as I move into the controls, and the comunnication between dynamics and graphics, it is harder and harder to make progress.

Is there any full documentation of the aircraft SDK ? If so, could you point me to it ? The tutorials are great, but some sections are missing, which makes it hard to know the full capabilities of the SDK.

Thank you very much for your help !

Antoine

Hello,

I am currently creating a hangglider model for Aerofly FS 2. Since I am not a 3d designer at all, I downloaded a free-to-use 3d model of a hangglider to work with. The problem is that it doesn't have square power-of-two-sized textures, so the aircraft converter won't work with that.

After some research, I found that ProxyTextures is a 3ds max plugin that can resize textures to the nearest power of two. However, it doesn't allow me to make the textures square, so I am still stuck at that point.

Does anyone know a way to "squarify" the textures in a 3ds max scene ?

Thank you for your help,

Antoine