XP11 vs FSX

[bonchie 2,305]

Question. IF LM is truly just using P3D for training purposes, why would they care about adding eye candy? 

 

OR, do they know what they are doing and the say "hey they agreed to the EULA!" knowing full well no one is using the license properly? But taking the money. 

 

 

Your premise is a fallacy. Some training outfits do care about eye candy and advancement in that area. 

 

You know what graphics the ATC 610 I used in IFR training had? A black wall and a plotter. 

 

Even in the professional arena, graphics capabilities are moving forward. And in the case of P3D, it seeks to be a multi-role simulator, not just a flight simulator. So higher fidelity of the graphics on the ground and lighting are actually priorities for them. And I think we've seen that with their approach toward graphics so far. 

 

They also have competition in XP, which does have a professional (FAA approved) license. So the market pressures to advance will exist. 

[SteveW 1,792]

Back in the old days for example to show a rotating cube the software might have generated a sequence of images of the cube in how ever much time it took. Then the sequence of images could be shown at 24 fps or whatever to represent movement. Let's imagine in a similar way an object could be dropped into a sim, whereby the simulator subjects the object to fluid dynamics analysis and produces a very high resolution set of tables for it and then run the simulation at far greater speed and accuracy with the tables.

 

This kills the "good idea" of running analysis during the sim running since the look up tables as I said are used to improve real time performance.

[sascha 314]

 

 

For me it is more or less evident that the weather can never look as good as it does in FSX / P3D with ASN, AS16 or other products before LR redefines the way some cloud types are rendered.

Apparently X-Enviro's team has found a wise workaround for the limitations imposed by the presently available datarefs for weather definition. It can draw weather up to the visible horizon, and not looking like a square or a donut around our aircraft. I'm not sure if they were also able to kill the fog wall effect, or the Moon being seen across overcast or bellow ground level under some weather conditions involving fog... ?

 

Well never is a long time, especially as you already go on in your second paragraph to mention how Xenviro has worked around the limitations.  And presto, weather in XP11 already looks just as good, maybe for some even better than FSX/P3D.

 

So not never, eh? Give it a couple of months (not even years like P3D) and I'm sure we will all be stunned.

[Mountain Man 142]

Back in the old days for example to show a rotating cube the software might have generated a sequence of images of the cube in how ever much time it took. Then the sequence of images could be shown at 24 fps or whatever to represent movement. Let's imagine in a similar way an object could be dropped into a sim, whereby the simulator subjects the object to fluid dynamics analysis and produces a very high resolution set of tables for it and then run the simulation at far greater speed and accuracy with the tables.

 

This kills the "good idea" of running analysis during the sim running since the look up tables as I said are used to improve real time performance.

 

Like I said, it's a debate that will never end.  The fact that X-Plane uses blade element theory in real-time, and it works, is as good an argument as any that it's a viable method for simulating flight.  The fact that FSX/P3D uses look-up tables in real-time, and it works, is as good an argument as any that it's a viable method for simulating flight.  That's pretty much where the debate should end.

[Paraffin 2,197]

Back in the old days for example to show a rotating cube the software might have generated a sequence of images of the cube in how ever much time it took. Then the sequence of images could be shown at 24 fps or whatever to represent movement. Let's imagine in a similar way an object could be dropped into a sim, whereby the simulator subjects the object to fluid dynamics analysis and produces a very high resolution set of tables for it and then run the simulation at far greater speed and accuracy with the tables.

 

This kills the "good idea" of running analysis during the sim running since the look up tables as I said are used to improve real time performance.

 

At the risk of getting into an "X is better than Y" argument....  :smile:

 

It seems to me that the method of running tests and then creating tables for an aerodynamic model has one basic disadvantage compared to realtime modeling. It has to be based on a static series of environmental conditions present when running the wind tunnel (or whatever) tests.

 

Test runs can be made in different temperatures, crosswind directions, density altitude etc. But it's impossible to simulate everything the model might encounter once it's out in the wild, especially when it's more than one variable. A lookup table sim has to interpolate when it encounters something that's in-between two different test conditions. Having high resolution from a high-speed offline run doesn't help in this case. 

 

With realtime aerodynamic modeling, a plane can encounter different weather conditions which are modeled as their own independently variable systems. The plane enters a cloud, or encounters a gusting crosswind, or a temperature inversion layer, or maybe all of this at once, and can respond dynamically to the change in environment. I don't see how a lookup table-based simulation can be that flexible in responding to changing conditions around the aircraft.

 

BTW, this is just theorycraft. I don't know how much realtime blade element modeling X-Plane is actually doing with each flight model cycle. But whatever it's doing, at a default setting of 2 flight model cycles per animation frame, it has the potential to be highly reactive to whatever environment the plane is flying through.

Like I said, it's a debate that will never end.  The fact that X-Plane uses blade element theory in real-time, and it works, is as good an argument as any that it's a viable method for simulating flight.  The fact that FSX/P3D uses look-up tables in real-time, and it works, is as good an argument as any that it's a viable method for simulating flight.  That's pretty much where the debate should end.

 

True, there's no arguing with end results as long as they both work well enough!

[SteveW 1,792]

If we choose to work out the flow of air over a wing we can use the data collected, we don't need to keep on doing it. The debate ended with that fact.

 

Look up tables for aerodynamics and applied temperature, humidity, dust accumulation, whatever, would be no less flexible than a look-up table for say, arctan. In XP it's not really real-time anyway it's not worked out per frame or even in high resolution due to performance limitations. Which in other words might benefit from look-up tables. I would say the idea is good, but inappropriate until we get spare performance.

[Mountain Man 142]

 

 

I would say the idea is good, but inappropriate until we get spare performance.

 

But it works, and by all accounts it works very well, so it's silly to call it "inappropriate".

[LAdamson 240]

But it works, and by all accounts it works very well, so it's silly to call it "inappropriate".

It's really quite a simplified approach. All aerodynamic surfaces are not accounted for, as well as interactions between fuselages, wings, etc.   At best, it's ball park.  The higher end programming uses a combination of blade element, lookup tables, and years of "black magic" experience.  You can't just stuff a plane into plane maker with blade element, and expect it to be a realistic replica.  

[SteveW 1,792]

Perhaps the use of look-up tables vs fluid dynamics is misunderstood. The use of lookup means that the code can maintain a linear time to frame. We can take as long as we like collecting data on every possibility in whatever detail we like and produce as many tables as we like outside the simulation time. Those "any atmospheric conditions and situations" will all be handled perfectly accurately down to a predefined resolution we choose. Application of the tables in whatever situation produces a linear time to frame. But really actually working out fluid dynamics in anything other than a rudimentary fashion like XP does will require too much CPU for the time being, and will take different amounts of time depending on the math applied at that time.

 

 

But it works, and by all accounts it works very well, so it's silly to call it "inappropriate".

To work out fluid dynamics is inappropriate when we don't have spare CPU time, I didn't say it does not work, or even work unwell.

[Humpty 751]

Oh no Not again, enjoy what you have , sometimes i wonder we are flying more or posting to these kinda threads more  

[Murmur 3,941]

Oh no Not again, enjoy what you have , sometimes i wonder we are flying more or posting to these kinda threads more  

 

+1.

[SteveW 1,792]

Oh no! Party poopers.

 

[Mountain Man 142]

It's really quite a simplified approach. All aerodynamic surfaces are not accounted for, as well as interactions between fuselages, wings, etc.   At best, it's ball park.  The higher end programming uses a combination of blade element, lookup tables, and years of "black magic" experience.  You can't just stuff a plane into plane maker with blade element, and expect it to be a realistic replica.  

 

Everything about flight simulation is going to be a simplified approach when you're trying to run it in real-time on the average household computer, including look-up tables.  There's a practical limit to how much data can be processed.  For that matter, even big, full-motion professional simulators costing hundreds of thousands of dollars have been criticized for reinforcing bad habits in pilots because no simulation is perfectly accurate.  In the end it's all just an approximation to one degree or another, and no one approach is inherently superior.

[SteveW 1,792]

...but fluid dynamics will ultimately be superior if the CPU power was available for the reasons given that it really actually works out what's happening as it happens. Eventually to compete with accuracy, a table set gets to a size where look-up becomes longer than algorithm. Anyway that kind of thing will eventually be incorporated in "graphics" cards which will take responsibility for dynamics and environmental conditions on the objects in the sim, the environment being a complex object. So we could create a water space, apply gravity to it and drop in objects to see if they float, all without "code".

[airlinejets 709]

 

 

I wasn't too popular on X-Plane boards back then.....

 

..some things never change.