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  #1  
Old 11-30-2017, 06:52 PM
tridge tridge is offline
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rapid vehicle prototyping suggestion

Something that would be terribly useful in RealFlight would be an option in the physics editor "save physics model as FBX". What it would do is create a rough graphics model from the current physics model. The user could then edit that FBX file if they wanted to refine the graphics (adding a color scheme, giving nicer curves etc), but they would also be able to fly it as-is and get a vehicle that does at least have all the element of the physics model showing up in flight.
The physics model should have all the information it needs to do this, as it is showing a wire-frame model already in the editor. When it saves the FBX it could even use the right airfoil shape, and include the pivots in the right place and orientation.
I suspect this would be quite a large piece of work, so maybe this is too much for KnifeEdge to do, but I thought I'd put it in as a request in case there is a KnifeEdge developer who has the time to do it.
Alternatively, I think that this could be done by the community. Maybe a blender plugin to load a rfvehicle file and create a 3D model would be possible?
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  #2  
Old 11-30-2017, 09:10 PM
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csgill75 csgill75 is online now
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This would also be a way for people to easily steal other peoples artwork. I don't ever see this happening. Most people here spend a lot of time and effort creating the models here. Some take months. Most if not all would not like people coming along, changing one or two things and posting it up on the swaps as their own model after working through the winter on a project for us to enjoy.
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  #3  
Old 11-30-2017, 11:16 PM
tridge tridge is offline
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Originally Posted by csgill75 View Post
This would also be a way for people to easily steal other peoples artwork.
It wouldn't give you the artwork the user has created. It would give you just the shape of the physics model, which will be extremely crude as compared to the amazing models that have been created by the community on these forums
What it would allow is for someone to create a complete alternative set of artwork for an existing model. It would have the same physics, but would only look the same if someone went to a lot of trouble to create the artwork to be identical.
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Old 12-01-2017, 10:28 AM
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Quote:
Originally Posted by tridge View Post
It wouldn't give you the artwork the user has created. It would give you just the shape of the physics model, which will be extremely crude as compared to the amazing models that have been created by the community on these forums
What it would allow is for someone to create a complete alternative set of artwork for an existing model. It would have the same physics, but would only look the same if someone went to a lot of trouble to create the artwork to be identical.
If you want something.. do the work.
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  #5  
Old 12-01-2017, 11:18 AM
Flapper Flapper is offline
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I don't see much distinction between the suggestion and what can already be done - I do it a lot for personal models.
a. Find an existing that is as close as you can get to the look/shape of the desired model, and make a copy.
b. Edit the dimensions, airfoils, weights etc. to match the "real" version .
c. Create a new color scheme, if desired.

Doing this has resulted in planes that are very, very faithful to the "real" ones I fly in behavior. So good, I use them as prototypes to fix whatever flight issues they (and the "real" ones) may have - change incidence, thrust angles, CG etc., and invariably the same done to the "real" one fixes its issues too.

Yes, a shape may not look completely correct as the base plane may not be the same as the "real" one. But that's where using the design tools come in - to build your own that does look like the "real" one, exactly.
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  #6  
Old 12-01-2017, 04:54 PM
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Ryan Douglas Ryan Douglas is offline
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Using a similar visual model as the basis for your own custom physics is certainly a valid, useful approach if you donít have the ability/donít want to invest the time in creating a more accurate representation. In fact, prior to G3 thatís all anybody could do! But that assumes you can find a visual model that is in any way similar to your design. I canít speak for the ArduPilot community, but I imagine the impetus for this request is the fact that experimental designs can be radically different from anything that already exists, making it pretty difficult to find a suitable visual basis.

(Iím not seeing the risk of being able to steal anyoneís art. As far as I can tell, that was borne out of an initial misunderstanding of the feature request.)

The ArduPilot developers are doing sophisticated things with RealFlight, which is very cool! Frankly, they are advancing the state of things like flight controller technology and aircraft design in a way that benefits the entire RC industry. Some of the things theyíre doing (or attempting to do) with RealFlight and the questions theyíre asking here may feel a bit foreign. Theyíre coming at RealFlight from a different angle than everybody is used to on these forums. For one thing, they need art primarily in service of the research and development work theyíre doing, not so much as something to be enjoyed as an end unto itself. That is quite different than the average RealFlight user. And if they poke and prod at RealFlight and have questions about specific behaviors or the validity of numbers being reported, that is not them looking for ways to tear down the product; they need to understand things at that level in order to do their work, and to know that the simulation is dependable & accurate. If an area of potential improvement is identified and physics improvements come out of it, that benefits everyone!

I think I sense some protectiveness from the existing RealFlight community. The ArduPilot developers (and anyone else who may come along later doing similar kinds of work) are not doing anything to undermine the RC hobbyist experience, though. Itís more like the opposite, and youíre getting a window into a world you wouldnít normally see. The bottom line is there is room for both. Letís make them feel welcome here so that everyone can learn from each other! After all, you guys know a lot of things about RealFlight that they donít.
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  #7  
Old 12-01-2017, 08:40 AM
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csgill75 csgill75 is online now
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If it's just the physics you want, we can already do that. Copy the RFvehicle file from one aircraft to the other. The RFvehicle file is the physics.
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  #8  
Old 12-01-2017, 08:52 PM
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Jeremy Sebens Jeremy Sebens is offline
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Tridge,

I think I understand the feature you're outlining, but just to be sure, here's my interpretation:

You'd like to be able to create a vehicle without having any visual art to start with. Instead of starting from an FBX, you want to make a physics model in the editor as the starting point (wings, fuselages, engines, etc.). That physics model would then be used to create a (very simple) visual model.

In essence, rather than letting the art drive the physics, you'd like to be able to have the physics drive procedural art. Is this correct?

We've considered this in the past, and I like the idea! You're right that it would be a lot of work. There are some real issues that would need solving, particularly around fuselages, which currently rely on art for their geometry. But with more folks using RealFlight for engineering purposes, it's worth some consideration.

It's an exciting time in the model/UAS world, and I'm really happy that RealFlight is useful to these efforts.
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  #9  
Old 12-01-2017, 11:03 PM
tridge tridge is offline
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Quote:
Originally Posted by Jeremy Sebens View Post
You'd like to be able to create a vehicle without having any visual art to start with. Instead of starting from an FBX, you want to make a physics model in the editor as the starting point (wings, fuselages, engines, etc.). That physics model would then be used to create a (very simple) visual model.
yes, that's right. If the code required it then you could start with a cube, or single wing for graphics model (I can imagine the code may get upset if there was no graphics model at all), but it would be ignored in the generation of the FBX.

Quote:
In essence, rather than letting the art drive the physics, you'd like to be able to have the physics drive procedural art. Is this correct?
yes
Quote:
We've considered this in the past, and I like the idea! You're right that it would be a lot of work.
yes, I thought it might be.
I think it would be possible to do this separate from KnifeEdge though - the rfvehicle file looks like it has the required information.
Quote:
There are some real issues that would need solving, particularly around fuselages, which currently rely on art for their geometry.
yes, though I think just treating the fuselage as a box would work to start with.
The idea isn't to get it perfect - it would just give a starting point. The user could then refine the shape in 3ds max or blender, and then use the very cool "fit to visual" in RealFlight to then map that to the physics model.
Outside of the engineering use case that I'm interested in I would have thought this would make
model creation easier for everyone. Being able to start with a FBX that has the right airfoils, pivots, angles and sizes would probably make creating models a lot easier. My primary motivation is the engineering use case however.
Cheers, Tridge
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  #10  
Old 12-02-2017, 02:33 AM
adrenoline 60 adrenoline 60 is offline
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Self flying? Self Replicating?
The Machines trying to take over Again.
Security!
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Last edited by adrenoline 60; 12-02-2017 at 02:48 AM.
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  #11  
Old 12-06-2017, 07:33 PM
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Jeremy Sebens Jeremy Sebens is offline
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Good points, Tridge. I think you're right - all the information you need is present in the .rfvehicle file.

Creating an entirely new vehicle would still require an FBX or KEX, but it could be a very, very simple one - a sphere or box would suffice. You could also use pretty much any existing vehicle as a basis.

The FBXSDK is fairly straightforward, so a developer with the time should be able to construct geometry from the physics file and write out an FBX.
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  #12  
Old 12-06-2017, 10:36 PM
12oclockhigh 12oclockhigh is offline
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Pardon Me

Pardon me for jumping in, but I think that you can already rapidly prototype a simple graphic vehicle in Max. Your idea of having the physics editor pop out simple designs would incure the freight of what max is doing.

Now if you are saying, have a dozen stock simple graphic designs as templates, I can see that. RF will never be 3D studio, nor should it be.
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