Help! Why is FG so bad?

[hans05]

Hi all,

after watching some DCS videos and looking at some of your P3D/X-Plane pictures I start to really wonder:

Why does FG look so overwhelmingly BAD compared to all those flight sims????

From outside AND inside even the best FG-aircraft look like a kids drawing compared to e.g. DCS. And I understand that DCS is still producing decent frame rate.

Oh, and this is a serious question! I do NOT want to just rant, I am really interested on technical level how FG can be so ugly and non-performant at the same time. Do they use a bad render-engine? Or are the models bad? What would happen if the models in FG would be more high poly, would the frame rates drop?

Xmas-greetings,

hans

[D-ECHO]

Hi Hans!
I can't really second your opinion that FG looks overwhelmingly bad, but here are some thoughts of mine, why others might look better:
-low-poly models: Many, mostly older FG aircraft were created using very little polys (the old dash 8 comes into mind), although AFAIK the consensus from tests and discussions were that high poly numbers don't really much hurt the framerate
-textures: this is IMO one of the biggest problems, it's difficult to get free, good textures and that's why many cockpits look 2d-likeish and the terrain sometimes looks unrealistic. The work of Gilberto was a huge leap forward there
-shadows, lighting: is often not implemented, although possible (lightmaps, ALS interior shadows)
Still, when looking at the IDG-A32X, 707, C172, Space Shuttle I can't really understand why you consider them looking bad, maybe you could explain what exactly bothers you?
Regards

[V12]

Why ? Here is answer :

FSX 737 vs FG 737 :





FSX A321 vs A3xx in FG (best developed aircraft in FG) :





FG's A3xx is graphicaly almost equals with FSX's one, but far better simulated with fully functional fly-by-wire, developer now working on FMS mCDUs. All other FG aircrafts are not competitors for A3xxx.

Payware FSX / P3D Concorde-X (not my screenshot) vs 3D improved FG Concorde :





Scenery and clouds rendering - is this image nice ?



IMHO, it is ugly, sometime FG can do it really nice :



But 12 years old FSX augmented by freeware live weather utility FSXWX again win :

[hans05]

@D-ECHO:

I am currently trying to improve the EC665 Tiger. For the work in progress I deleted all textures and gave the outside a grey material.
And what do I get in FG? Or rather what do I NOT get? Shadows! I wish I could publish a picture to show you what I mean. E.G. the pilon-wing does not cast any shadow on the fuselage. I modeled seams and foot-holds and I have to give some part of the surface that should be in the shadow black material to make it look like shadow. I found that extremely embarrassing and I wonder why this does not work and how DCS makes this work. In DCS you have realistic shadows where it should be. This is already sooo basic, that I could hardly believe my eyes when I saw...uhm did not see the shadow.

I wondered whether I am doing something wrong, but then, other aircraft in FG do not look any better.
And indeed I also noticed that high poly does not impact the frame rate too much. I am doing an extremely high poly and had planned to bake a normal map to a low poly copy. But when trying my model in FG I noticed not a single frame rate less than the original low poly that I started from.

So you see that I am REALLY interested in the explanation/solution to the quality issues here.....

[V12]

Default render or ALS render doesn't support cast shadows. Only Rembrandt, but this one is obsolete and very slow. And about framerate - there is possibility to throttle framerate - check View - Rendering Options menu. Probably, You have checked this option.

[D-ECHO]

@hans05: This topic might be interesting for you: https://forum.flightgear.org/viewtopic. ... it=shadows

[hans05]

@D-ECHO:

That is indeed an interesting topic. But no help in any way, it just supports what I had understood already: ALS does not (really) support shadows (the shadow boxing is really BAD) and Rembrand is dead and slow.
So still the question is: How do all the other flight simulators do it (so much better than FG)?

[V12]

IMHO, because in FG developers can't use patented and licenced highly optimized software code for shadow solution.

[hans05]

Mhhh, might be correct. I understand that FG uses OSG for 3D rendering. OSG does support shadows. So is that particularly slow?

D-ECHO has become quiet....

[V12]

I never seen Open Source software running as fast as payware. Blender vs 3DS Max or Maya, Photoshop vs Gimp, Sony Vegas vs any O/S videoeditor, etc, etc, etc. OSG support shadows - if I'm correct, Rembrandt is running on OSG. But is SLOW, because OSG is so slow. And there are many other things. Big framerate killer in FG is nav display implementation, it is unbelievable slow with route with many waypoints, even slower with enabled Traffic layer for TCAS. Another fps killer is cloud generator running on Nasal interpreted language with enabled terrain presampling and thermal lift generating. For example - 12 years old FSX can display clouds with visibility limit 160 km and decent framerate around 20 fps. This setting in FG totaly kill fps...
Biggest problem is multithreading optimalization - I never seen 100% CPU load on my quadcore CPU. When I flew on backup machine with hyperthreaded quad core i7 2670 and Quadro 1000M, maximum load was only 20% with 5 fps over Himalaya. Graphics card was not the bottleneck.
But FG 2018.3.1 is faster, than 2016, 2017 and 2018.1 and 2018.2 releases.