Tuesday, February 23, 2010

F-35 Project update

F-35A Final outer model for Beta release

While the Beta build is still not complete yet (I'm still adding MFD functionalities), I've finally managed to go through all the CR's from the Alpha and implement fixes where possible.
There is still some work to be done, but in any case I will release the Beta 1 the next weekend (even if it will only have the AA-1 model and still miss some of the MFD functionality).

Here are the changes implemented in response to the Alpha test feedback:

  1. Nozzle animation incorrect -> Redone nozzle animation (but still linked to throttle)
  2. Jaggies nearby the engine intake area -> Modified fuselage model, (but it is still slightly visible)
  3. Excessive gap between engine nozzle and fuselage -> Modified geometry to get rid of the gap on AA-1 model (NOTE: AF-1 and subsequent planes have a different design)
  4. Wheel/tires animation incorrect -> Fixed wheel parameters in .cfg file
  5. Navigation lights missing -> Placed lights in .cfg file
  6. Covers for auxiliary air intakes missing when using SHIFT+E+4 command. -> Modeled auxiliary air inlet cover, but I will not model additional ribbons and covers as I'm saving polys for the weapons model
  7. Irregular bumps in the external model -> Redone fuselage geometry
  8. Poor detail in the refuel receptacle -> Refuel receptacle modeled
  9. Poor detail in the nose landing gear -> Redone most parts of the main gear and applied new textures.
  10. AIM-120 not attached to hardpoints -> modeled hardpoints for AA-1 will model LAU-147 for operative model
  11. Nose gear door detail/accuracy not good enough -> Redesigned hinge and added actuator and new texture
  12. Request to model the lights in more detail -> No additional modeling (issues in Boolean operations geometry), but better texture. Miscellaneous other actions (not requested by testers)
  13. Wrong size of main gear wheels / tires -> Modified model
  14. Add detail to the main fuselage texture diffuse/spec/bump -> Enhanced textures
  15. Fix mistake in texture UVW in the inner side of air intake -> Fixed
  16. Add separate moving part for weapon door hinge - visible on real plane on closer inspection, not modeled -> Modeled (note:unsure if real design is changed in AF-1)
  17. A/c is sitting rather low on the main gear. Changes to the animation sequence and contact points needed. -> Changed animations and .cfg file, a/c now sits correctly

To do list:

- Better afterburner effect

No action / CR reject:



NOTE: VC functionality has been completely redone with new custom HUD by Jivko Rusev and Scott Printz and new custom MFD - The list below covers only issues on the Alpha build that are applicable to Beta

  1. Virtual cockpit frame rate low / excessive number of polygons -> Optimization led to a 15% reduction in polys and removal of 2 texture sheets
  2. Minor texturing UWV misplacement on cockpit floor -> Fixed
  3. VC night lighting too bright -> Changed .fx file
  4. Incorrect tooltip showing "parking brake" in the battery area -> Fixed
  5. Visual hole aboce the pedals (polygons missing) -> Fixed
  6. "No Hold" texture stretched above ejection seat -> Fixed
  7. Stick movement excessive if compared to real F-35 stick -> Fixed

To do list:

- Complete rework of the cockpit XML (80% done - Many MFD buttons/pages are now functional)

No action / CR reject:

- "patches" on the side of the Vc glass are unconnected to the canopy; Action: modify the Vc model -> No action. Unclear how the area looks like in reality.

- Explosivc cord not connected to glass -> No action. Better leave as is to avoid clipping.


Note: special thanks to Roberto Leonardo for some of the fixes.

  1. Excessive top speed -> Redone Wave drag table. Now it is approximately Mach 1.69
  2. Weak brakes -> Fixed brakes effectiveness
  3. Pitch changes depending on throttle setting -> Fixed/mitigated with new .air file
  4. Pitch changes when activating virtual speedbrake -> Fixed/mitigated with new .air file
  5. Low roll rate -> Fixed with new .cfg file
  6. Excessive loss of energy during high-G turns -> Fixed with new .air file (may be slightly too good now?)
  7. Virtual speedbrakes not much effective -> Fixed
  8. A/c prone to yaw instability during takeoff run -> Mitigated (but not completely solved - further stabilization led to a behaviour unresponsive to rudder)

To do list:

-Nothing, awaiting Beta test

No action / CR reject:

- High AoA dynamics causes excessively low stall speed (75kts)-> No action - left as is not to screw landing behaviour (which seems good)

- Check landing attitude AoA -> No action. Landing behaviour seems good for most users

- Full flap deployment happens at low speed -> No action. Left under FSX automatic control as maneuver flaps

Tuesday, February 16, 2010

F-35 Lightning II - project update and some screenshots

F-35 AA-1 climbing nearby Edwards AFB (photoscenery made with FSET). Fuselage textures are now slightly more detailed - and for AA-1 I've added a "scorched" effect to the paint nearby the APU exhaust (as happened in the real AA-1 - AFAIK, exhaust has been moved to the lower side on all models except the -C for deck crew safety concerns...)

Testing low speed flight characteristics neaby Edwards AFB. So far so good. Most, if not all, of the issues in the Alpha build are solved and the plane flies smoothly and it is easy to fly (with thanks to Roberto Leonardo's tweaks especially in the tight turns department).

On of the major areas of improvement is the MFD which is now truly multifunctional, and allocates fewer texture sheets. Some of the MFD pages will be accurate to their real counterparts - some others will be less accurate but I'm confident that the final layout will be a reasonable compromise.

The general cockpit layout is accurate, with some exceptions and artistic licences here and there. For example the canopy frame is the "weight optimized" version - somewhat different from the actual AA-1. Another example is the lights panel, which sits where an emergency electrical panel should be. In geneal I've tried to balance accuracy, useability, graphics and...fun. Yes, I am one of those who still thinks that, afterall, it's just a videogame :-)

Last, but definitely not least, there is the new HMD by Jivko Rusev and Scott Printz. Basically Jivko has taken Scott's excellent F/A-18 HUD code and adapted it to the F-35. This new HMD gauge is as close as possible to real one (given the information publicly available) and it is a huge step forward in cockpit useability. Scott and Jivko have kindly provided the authorization to include it in the package - and looking at the screenshot I took I realize it does not do justice to their work... It looks awesome. Trust me.
Well... Above are some screens - as promised. I did not have much time to work on the F-35 lately, so the Beta is 10 days late... and the chances that I will be able to complete it before the next weekend are pretty small. I do not think I've much to add to what I wrote below the screenshots... but in short: the visual model is even more accurate, the flight model is better, the VC has more functionality and there is a great new HMD by Jivko Rusev and Scott Printz.
Now, I just hope I will find the time needed to complete it in the next weeks...

Monday, February 15, 2010

How to manage extremely complex 3D models in FSX

One of the issues I had devoping the F-35 was the extreme complexity of the model in terms of polycount - which led to several issues while compiling the model.
The problem I had was related to some of the "undocumented" FSX limitations. It was advertised that FSX models had no restrictions in terms of poly count, making it possible to create extremely complex models - far beyond FS2004 limits.... And this is true, with a catch.

There is still a 64K buffer limit for the draw calls - which in FSX are "grouped" by material. That is, you cannot have a unlimited number of vertices/polygons using EXACTLY the same material - as the polys of every part (even if disconnected) using the same material concur in the same draw calls buffer: this may result in:

  • FSX exporter fails to compile
  • Mdl is compiled but some parts are not showing correctly in FSX (either do not show at all, or they appear black or they cast shadows and don't show at all... I've seen every kind of weirdness)

  • Create several slightly different copies of the material in gmax (e.g. Engine_material_1, Engine_material_2, Etc. which may differ just by 1 point of specular power in the basic material proprieties so they will look the same in FSX)
  • Assign Engine_material_1 to some of the engine parts, Engine_material_2 to others, etc. so that each engine part goes into a different buffer
  • Compile and be happy
This is the magic "trick" that allows extremely complex models in FSX.
ONE CAVEAT: if this is your case, it is likely you have exceeded the visual complexity reccomended by Microsoft. That means you may have users that will complain about the frame rates when compare your model to default ones...

To be honest this was not the first time I've encountered this problem - but I saw that this trick was unknown to some designers and I wanted to share the knowledge. By the way, I'm told that similar issues (and solutions) happen in FS9.

As for the F-35... in Italy we say "appetite comes with eating", meaning that once you started making one thing it may be difficult to stop. In this case, I started a minor rework of the MFD to add some functionality...and it turned into a major remake (which was also helpful to reduce the number of textures). As of today, HSI,MAP,ENGine,FUEL,FCS sub-screens are working and 99% complete... The other functions (COM,ICAWS and WEApon subscreens) are much easier to make - the problem is that I do not have much time to work in
I promise I will post some images tonight.

Thursday, February 4, 2010

First flight of the fifth real F-35

The fifth F-35 prototype BF-03, landing after its first flight.

While I am struggling to find the time to complete and pack the Beta version of the virtual Lightning II, in the real world the fifth F-35 had its first flight. It is the BF-3 (that is the third STOVL prototype), and as you can see from the picture, it is completely painted in dark grey - which I assume it will be the standard livery for all the prototypes.

So, since the AA-1 has been retired, now there are four F-35s flying: AF-1 (CTOL), BF-1, BF-2 and BF-3. BF-1 and BF-2 are currently in Patuxent River and are undergoing a series of test flights that will culminate in the first actual STOVL flights - see http://www.jsf.mil/ for some cool hi-res pictures and additional details (including videos of the first lift-fan in-flight engagements).

As for the FSX projects... well, as I said I am struggling to find the time to work on it.
For those who are curious, the major differences from the beta will be:
  • an updated visual model with more detailed 3d geometry (especially in the landing gear and refuel receptacle aeras) and more detailed textures - with slightly different coloring.
  • a better flight model - with special thanks to Roberto Leonardo who provided some substantial tweaks to the .air file. The plane has now a more realistic turn performance, and a more "neutral" behaviour, in attempt to emulate the effects of an advanced FCC/FCS system.
  • more VC functionality: it is now possible to change the functions of the four areas of the MFD by picking from the menus on the bottom. At present, HSI (with map mode), RADAR/MAP (with terrain mode), FCS modes are working (but do not expect anything too fancy - I've extensively reused FSX code for those) - ENGine, (mock) WEaPon, COMmunication, ICWS and FUEL modes are planned. SWAP and MENU button should be functional, too.

The MFD functionality is the thing that needs more work... may be 10-12 hours. Hopefully I will complete it in the next weekend.

Last I need to apologize again to anyone who has sent me an email in the past few days - my email is working but I did not find the time to reply, even to messages that are quite important for the project.

Monday, February 1, 2010

First flight of the Sukhoi T-50

Sukhoi T-50 first flight

A very interesting plane has made its first flight a couple of days ago - the Sukhoi T-50, that is the first Russian stealth fighter. Looks like a YF-23/Su-27 hybrid to me...and it also makes some of the Ace Combat 6 aircrafts look a little more lifelike... Here is a video of the first flight:


As for the Flight Simulator X F-35 project is proceeding in the right direction - and I'm confident that the Beta will be noticeably better than the Alpha in almost every respect. Hopefully it will be ready in a week or so.