This is getting really serious now. Nothing like pushing it to the limit.
Good luck on the end-spurt for the parts you need!
The colours for structures are usually annoying, especially if you want a black bulkhead for an intake or an exhaust, but you want the outside colour to be different from the group colour. I suppose AF99 is limited to 2 colours per item. Another thing I find annoying is the way a side texture flows around a bulkhead, and if I want it black, and I donīt want to use a separate insignia part as a "lid", a vertical line few pixels wide on one end of the texture helps, but it shows on the side too.
I started on the Main Landing Gear and found a fairly elegant way to build the Gear Doors which unfortunately is a bit more resource intensive than what I had originally planned. I also realised that there are still so many pieces left to do that it is highly impossible to add all the remaining pieces with the remaining Parts.
With 30 Components used, there is no way to save a few Parts by replacing a Structure with a Component. Also, there are no more Structures that can be built much more economically with a Component.
Up to this point, all changes to the model to use fewer Parts has not degraded the appearance of the model except for removing the Wing Fillets.
Within the limitations of Aircraft Factory 99, there are always some compromises that are needed build an aeroplane project. My choices are usually to get the shape as close as I can and leave out some "non-essential" details. What I absolutely HATE is when it is necessary to remove or simplify pieces that have already been built.
With the Parts Count up to 1177 (after adding some Landing Gear pieces) it is necessary to free up resources to continue building.
The Radio will be replaced by one that is more compact (and hidden) which should save around 10 Parts.
The Spinner tips will be changed to remove the first row of polygons and will now end in a flat instead of a point.
The attached screenshots show the places that will be be affected along with a bleed that would need a couple more Parts to fix if there are any left over.
The prior post shows the current state. Yeah, we are VERY tight at this point, but I knew that was happening when the Parts count broke 1000.
I very seldom leave an exterior strcture untextured unless it is a gun tube or fairing. I also don't generally leave anything set as the Group Colour which means I can change the Group Colour without affecting anything else such as when I added the Supercharger Intakes.
I do wonder what would happen if there are multiple untextured structures that all need to be different colours and all live in the same Group.
Regarding the need to texture the side of a Structure to give it a black opening, I have found that only two or three rows of black (very dark Gray because we NEVER use BLACK) pixels is sufficient. One row is used to set the actual colour and the other row is so that the colour doesn't change when the viewing angle is changed.
Keep in mind that although we can't fine tune the image on the texture file because each pixel is so large, we can locate those big pieces of coloured felt quite precisely on the aeroplane. Each pixel may be 2-3 inches square, but we can move it around by 0.01 ft or just over 1/10 of an inch. I was planning on covering this when I got to the appropriate stage of the Texturing Tutorial.
The Front Spinner Structures have been reduced by one section.
The Main Landing Gear is complete at this point.
Each Main Gear is 15 Pieces (8 actual pieces and 7 Glue Parts to make things look right):
Inner Wing Group:
---------------------
Inner Door Upper
Inner Door Lower
Outer Door Upper
Outer Door Lower
Strut Top - This is an Insignia Part only outward facing because the inside is behind the Inner Doors.
Strut Middle - This is in the foreground when view is below the Gear Doors.
Left Gear Group:
-------------------
Main Wheel
Strut Bottom
Recall that the Engine and Boom centerlines are 96 inches from the aircraft centerline. (Wing Station 96)
The Main Wheel centerlines are 99 inches from the aircraft centerline.
The Main Gear Struts are 89 inches from the aircraft centerline.
With the theft of Parts from the Spinners and addition of Parts for the Main Gear:
Parts Count is now 1177 of 1200.
Note that there is a slight bleed of the Outer Wing through the Supercharger Intake.
This will not be adjusted until I can see the interaction with the deployed Flaps.
The Pitot Tube was relatively easy and only used 4 Parts as expected.
The Glue for it is particularly interesting because it isn't flush with the bottom of the Wing.
It is at a slight angle which creates a bleed when seen below the Wing's Trailing Edge from aft.
This angle is here to avoid a bleed when the Outboard Flap section is deployed.
My choice is usually to leave in small bleeds to avoid a huge bleed if a choice must be made. I believe the small bleeds are a bit less distracting.
The Nose Gear is also complete. My representation of the shimmy dampers is to just put in a part to acknowledge their presence which is better treatment than the Main Gear received. I don't think folks care much if the Main Gear is missing its torque links but if they are missing from the Nose Gear, it would stand out.
Parts Count is now 1184 and some choices need to be made:
The Guns will certainly be only 2D pieces for lack of resources.
I had intended to put in Dive Recovery Flaps even though the early J model didn't have them. They would be enabled by changing the AIR File and by adding an outline in the texture of the underside of the outboard wing.
I also wanted to have the scoops at the side of the Cowl. (Were these for Spark Plug cooling??)
The Guns can be added by Gluing to the Nacelle in the Main Body Group but that would require 10 Parts for the 5 Guns and the Glue for each Gun. Alternatively, they can be added to the Nose Group but would then would need to be Insignia Parts to avoid bleeds. As Insignia Parts, the far side Guns would always disappear.
A few Parts can be recovered by converting the Supercharger Intake to be 6 sided sections instead of 8 sided, but I don't want to do that.
With such a high parts count it always comes to decisions, and Iīd definitely agree with omitting some small or less important details in favour of keeping the quality of more noticeable shapes or those that are more integrated into the aircraft!
Itīs actually quite exciting to see how the job is progressing!
This is about as serious as I have gotten with running out of Parts. Surprisingly, AF99 hasn't had problems yet.
Other times, it has been running out of Components or having display problems which require simplification to some unpredictable degree.
It isn't just a matter of leaving out small pieces; It is more a matter of what we consider essential in a design. I have always thought the Supercharger Intake was a rather strange looking feature on the P-38, so this model had to have them.
The P-38 Lightning was typically armed with:
A 20 mm Cannon with 150 rounds.
Four .50 Cal machine guns with 500 rounds per gun.
From drawings, it appears that the 20 mm Cannon is aligned vertically with the Engines' Thrust Lines which puts them on the vertical center of this model. As expected, it is on the lateral center line.
From a Gun Harmonisation Chart the offsets of the machine gun bores are as follows:
The Upper MGs are 6.5 inches above the Cannon bore and 4.25 inches Left and Right of center.
The Lower MGs are 2.375 inches above the Cannon bore and 9.75 inches Left and Right of center.
The Cannon Muzzle is even with the Tip of the Nacelle. The MG muzzles are staggered to offset their magazine boxes in the nose of the aircraft.
Also from the Gun Harmonisation Chart, the ballistics of the Machine Guns and Cannon are all nearly identical.
Although the location of the guns makes for concentrated firepower to all practical ranges, it has another less optimal effect.
The guns and ammunition are quite heavy and located far forward of the aircraft's Center of Gravity and firing off the several hundred pounds of ammunition causes a large longitudinal shift of the CoG.
2000 rounds of .50 Caliber ammunition weighs 622 pounds.
150 rounds of 20 mm ammunition weighs 92 pounds.
The first screenshot shows the appearance of the Guns from the side. I believe the two lower MG muzzles need to be extended further forward. Although the Cannon can be placed in the Nose Group, the other Guns need to be Glued to the front of the Nacelle, so the total cost is 9 Parts.
The second screenshot shows the less than optimal appearance of 2 dimensional "Guns" and also show the rather poor way AF99 handles Group Glue between the OUTER Wing and Fuselage: The viewing plane happens to be on the aircraft centerline.
Itīs a real achievement to be able to get everything one wants in when the 150% limit keeps coming up. With luck some things can be done with fewer parts, and one can scrounge parts for whatīs still needed!
Thanks to several items in this design study I had a series of surprisingly successful gluing tasks on the "big plane" Iīve almost finished reworking. Iīve even managed to scrounge parts for the ventral machine gun by dividing a complicated engine+radiator structure into two, sequentially gluing some of it which was causing bleeds, and grouping the radiator with the propellers and spinners. There I used a convenient gluing sequence, so thereīs no bleeds at all! Amazing... The same with the 3 crew members (albeit very simple shapes), their wells and the walls on either side - nothing bleeds!!
Thanks again for all this lot!!
Cheers,
Aleatorylamp
Although the early P-38J did not have Dive Recovery Flaps, They were standard on later models of the Lightning.
The P-38 had a very low limit on its maximum diving speed.
The limit was not because of structural limitations but because of control limitations.
At around 0.65 Mach, the Lightning would enter "Compressibility" and the wing would lose lift AND the elevator would lose effectiveness.
This phenomenon was known as "Nose Tuck".
At this point on early Lightnings, the only option was to adjust elevator trim to attempt to pull out. Hopefully the recovery would happen before impact with the ground.
With the late J model Lightning, "Dive Recovery Flaps" were installed on the underside of each outboard wing panel.
When deployed, they would cause the nose of the aircraft to come up and to a lesser extent also act as air brakes.
Although my model is not intended to have Dive Recovery Flaps, I thought it would be interesting to add them to the model and prevent their use through the AIR file. For a later model Lightning, all that would be necessary would be to slightly change the texture of the underside of the wing and enable the "Spoiler" in the AIR file.
Strangely enough, Enabling the Spoiler is done by changing the Spoiler Angle in Record 320 to a non-Zero value. The "Spoilers Available" variable seems to have no effect. The deployed Dive Recovery Flap appears to be at an angle of 45 degrees so that is what I used even though the number here can be anything.
Temporarily, I changed my own AIR file to test the effect. It should look much better when textured and animated. It will also not affect my version of the Lightning because the pieces will not display when the Spoiler is not deployed.
The forward section of the Dive Recovery Flap has a chord of 8.5 inches. The Brace behind it has a chord of 7 inches.
Their location is from Wing Station 122 to Wing Station 180.
As can also be seen, I found it necessary to simplify the Supercharger Intakes to a Hexagon Structure to free up some resources.
The Panel area of the Cockpit has also been extensively modified but is not shown here because I have already gone through about 4 designs and am still not sure what it should look like.
There are small scoops on either side of each cowl which I believe are for spark plug cooling.
They look quite prominent in the current "Sharp" Component but may be much less visible when the Component is made "Smooth" for painting.
After adding those, the Resource count is as follows:
1195 Parts of 1200 allowed.
197 Separate Parts in the Assembly out of 200 allowed.
30 Components of 30 allowed.
6 Structures of 30 allowed.
For all practical purposes, the model is as good as I know how to do within AF99 limitations at this point.
Many improvements can be done within SCASM, but the purpose here was to build at least the exterior model entirely within AF99 limits.
There is still quite a lot of experimentation that can be done with the Fuselage to Wing Templates which I intend to do.
Next step with this model is animation of the current assembly.
- Ivan.
Hi Ivan,
Itīs certainly looking good. Congratulations!
Just a small query: I was wondering whether you were planning to put in wheel-wells that appear then the undercarriage is out, or is this perhaps not on your agenda because of the inexact animation which retards their appearance until the undercarriage is fully extended.
Cheers!
Aleatorylamp
The Wheel Wells are not on my list but not because the animation would be inexact; It is simply because I have expended 197 of 200 individual Parts.
To put in Wheel Wells would require a minimum of 2 Parts per Wheel which along with the Glue Parts adds up to 12 more Parts which are simply not available in the AF99 Project.
Sequencing the Wheel Wells to match the animated Landing Gear is actually rather trivial. I believe I have done this on most of my other projects using SCASM.
For the purposes of this Design Study, my goal was to build and texture the entire exterior model using Aircraft Factory 99 and Aircraft Animator.
SCASM was to be used for tasks that AF99 us clearly incapable of accomplishing such as the Virtual Cockpit view, and very minor Animation Refinement.
I wanted a model that as loaded into the simulator would show at least from the exterior view what can be accomplished with AF99.
(It was one of those: "If others can do this, why can't I?" kind of things.)
Using SCASM, There are really no practical limits to the resources available and the Fuselage to Wing Templates would be trivial to do.
With only SCASM limitations, I would also be adding in a couple hundred more pieces over the next couple of months.
As it is, I am more or less satisfied with what is here as long as I can get the model textured without breaking anything.
I see. Depending on priorities, of course not everything is possible. For me, sometimes a simplification works by putting the wheel wells with insignia down, tagged as gear down but unanimaterd in AA, into the body and the lower engine nacelle groups - this way I save the glue to keep the gear separate from the doors. Of course, with some doors closing with extended gear, it becomes difficult, as the closed doors then have to cover the wheel wells - but thatīs usually only on jets...
AF99 limitations, are very frustrating with complicated models. If itīs not parts numbers, itīs degree of complication. At the moment Iīm battling with the Zeppelin Staaken R.6 and the Gotha G.4, trying to include guns and crew. Itīs a nightmare with the transparent cabin and the hollow fuselage respectively, and looks like Iīll have to make those solid, and itīs taking much longer than I expected. Weīll see!
Anyhow, Iīm looking forward to watching how the Lightning will be textured and animated. That will doubtlessly be very interesting!
The model of the Lightning that was uploaded was animated though not textured.
Many things can be done with Aircraft Animator though not necessarily in the way that one might expect.
The Dive Recovery Flaos come in two sections per side. The Forward Section (the actual Flap) is animated pretty much as one might expect.
The Aft Section is also animated rather simply, but the axis of rotation has been shifted a bit.
The Lightning had Fowler Flaps that extended back as well as down. When fully extended, the leading edge of the Flaps werenearly even with the trailing edge of the wing. This can also be done was a simple rotation though again the axis must be shifted s.
Hi Ivan,
I find the whole concept of this design study extremely appealing, as it proves that complicated aircraft can indeed be produced decently with AF99 if one ably maneuvers within its limits. It also shows how an effective criteria of defining priorities prevents a lot of frustration.
I like your minimalistic, parts-saving use of 2D parts in certain areas - e.g. animated landing-gears struts - where 3D isnīt vital. (A fixed gear would be different, as it shows all the time).
Very nice, the Fowler flaps! AA does these really well if the axis is shifted correctly!
Re. dive-brake spoiler animation: Very interesting, how you manage the second rotating axis - Iīm still trying to figure out how it works! Iīve never had much success using the "H" factor, and usually hide certain sequence-sections differently, but less effectively. This, however, seems to be one of the "secrets".
The Aircraft Animator screenshots from my prior post along with the model that has been uploaded contain sufficient information for anyone with access to the Aircraft Animator package to experiment with and alter the animation for my P-38J. The model that was uploaded earlier includes the animated parts files that AA uses to save previous animation sequences.
This brings up a rather annoying "Bug" in Aircraft Animator that I have encountered numerous times:
There are certain animations that the package will add to the model but will not save to be used again.
The diameter of the Transparent Propeller Disk may be adjusted to 0.01 Meter in the MDL, but is only recorded to 0.1 Meter.
The P-38J has a propeller diameter of 11 feet 6 inches and I found 1.78 Meters to work well but it is only recorded as 1.8 Meters.
Aircraft Animator will record Flap animation sequences faithfully if the MDL file contains "Flap Retracted" pieces (as my Lightning model does) but will not record sequences if all of the Flap pieces are tagged as "Flaps Extended".
Aircraft Animator will also not record Spoiler animation sequences if the MDL only contains "Spoilers Extended" pieces as my model does.
Although AA does an excellent job of guessing axes of rotation, the odd animation sequence of the "Spoiler Brace" must be recorded elsewhere (such as the attached screenshot) and entered each time by hand.
There are other bugs as well in the "Motion Ranges" section which I have encountered in other projects but not on the Lightning.
I am glad there is some interest in this "Design Study". The Design Study aspect is why I am including so many of the specifications and other technical details on the P-38 as I go. Unfortunately, I was doing the building and posting the progress as I went, so it is not planned out ahead of time and the data and even the discussion may not be as organized as one might want.
I wonder if others are finding amusement in watching the development of a fairly complicated project which was pretty sure to run out of resources at some point and seeing the backtracking and rebuilds needed to stay under some ridiculously low resource limits. A couple weeks back, I would normally have taken a break and switched to a different project if I wasn't posting progress on this thread.
Regarding 2D pieces:
My preference would be to have done things with 3D Components in most places such as the Landing Gear Struts but there was really no option to do this with other design choices I had made. I wanted the Struts to be as near to the actual location as I could manage but from certain angles, the 2D Part leaves an obvious gap.
I believe in most cases that a 12 sided cross section is optimal with projects in AF99 as a compromise between a reasonable shape and cost in resources.
Some transitional areas in my models may go out to 16 or 18 sided cross sections to maintain a "Stream Line" where another piece joins.
(These models have always struck me as looking very much like a peeled carrot with all the flats and angles trying to approximate a round shape.)
Regarding animation and the H(ide) sequences:
I can tell you that sometimes what works according to the manual doesn't work on the actual model.
AA seems to like nice even divisible numbers in its sequences and sometimes has issues when it gets others.
Sometimes the issue may be one of an unpredictable "dead spot" in the animation; I ran into this with the BV 141B which would not display an animated landing gear even though it all looked fine inside Aircraft Animator. I spent a fair amount of time rearranging things and splitting Components which eventually cured the problem even though none of it should have affected anything at all.
Hi Ivan,
I think the only effective way of conducting such a design study is hands-on, as you progress. Prior planning would most probably make it too difficult to be practical.
The interesting thing is visibly how satisfactory results can be achieved within the limitations of the tools used - AA and AF99. I also wonder if others will be enticed to try and model with AF99... Decisions on where to simplify and what to eliminate are crucial, and your design study is a good example with excellent results. It is an art to find the way of getting things the way one wants out of these programs!! Thatīs the challenge...
I found this with my re-work on the Zeppelin Staaken R6 Giant, whose hollow fuselage, wood-lined inner cabin and transparent windows had so many individual parts that it stopped compiling at 99.5%, and had no crew or armament, and control-surfaces were only 2D. Iīd built it to see how these planes flew in FS98. For CFS1, however, we need guns and gunners!!
After putting in guns and gunners and making control surfaces 3D, even a simpler hollow cabin for a pilot inside gave bleedthrough and compilation problems, and couldnīt be done - but this allowed other improvements. After your comment about using a texture for more than one part I managed save three textures on wings and twin fins, so now wheels, engines under-wing tank and windows could also be textured. Iīm sure it can be done better still, and that may be for the future. I also managed to get a virtual cockpit in, and now it stops compiling at 141.6%... but, I have no ventral machine gun... no parts left! Another decision!
For the flight dynamics I decided follow your suggestion and adapt the CFS1 P51 .air file. It went rather well! The FS98 one wouldnīt let it move on a dirt airstrip without reducing the dry weight. I used the data from the original FS98 .air file, as well as more detailed authentic engine parameters from the FS2002 version. Thus, the old high-compression altitude-rated aero-engines can be emmulated very well with the turbocharger parameter! This way the simmer doesnīt have to watch about not exceeding 70% power at low altitudes, and can use full power because the .air file will manage this fine.
Iīll soon be uploading this model!
Cheers,
Aleatorylamp
Last edited by aleatorylamp; January 8th, 2015 at 07:29.
Reason: spelling
As mentioned earlier, the maximum Mach limit of he Lightning was quite low and created a tactical limitation.
The maximum allowed speed was 0.65 Mach because the aircraft would start to buffet and the nose would tuck at 0.67 to 0.675 Mach. Exceeding these numbers by any significant amount would mean a loss of controllability until the aircraft had lost enough altitude to reach denser air.
The actual margins for speed were surprisingly small:
The P-38J/L could reach 425 MPH at 27,000 feet on Military Power.
It could reach around 445 MPH with War Emergency Power.
The P-38 was a fairly sleek aircraft and heavy aircraft with a lot of engine power and would gain speed very quickly in a dive.
Mach 0.65 at 30,000 feet is only 440 MPH. At 20,000 feet it is only 460 MPH.
It didn't take much to go past the limit. What this meant is that the Lighting could not follow almost ANY contemporary fighter in a dive without losing control effectiveness.
Even at Sea Level, 0.65 Mach is only 495 MPH. A wartime P-38 operates well below this limit but modern Unlimited Class air racers routinely exceed this speed.
Texturing the Pilot was fairly easy as expected. The textures came from one of the other models I built (the P-40C).
The Nacelle required two files as expected.
Scale is 12.80 feet over 256 Pixels.
The Cowl section required one file per side.
Scale is 16.64 feet over 256 Pixels.
At this scale, the Cowl and Boom sections are a very tight fit.
Normally, I have a 1 pixel border on the texture file so I can see if an object is getting too close to the edge.
With this Object, there was no hope of avoiding BOTH edges and all that could be done was to center the object on the texture so that it would not run off either edge.
The Radiators, Tails, Spinners, and Fins/Rudders also used one file per side.
Scale is again 16.64 feet over 256 Pixels for the Radiator and Tail Boom.
Scale is 15.36 feet over 256 Pixels for the Fin / Rudder.
Scale is 8.00 feet over 256 Pixels for the Spinner.
At this point about 1/4 to 1/3 of laying out the textures has been done.
....A correction to the prior post:
Cowl and Boom required TWO texture files per side.
Scale is 16.64 feet over 256 Pixels.
The Wing Center Section required one file for both sides.
Scale is 20.48 feet over 256 Pixels.
Each Outer Wing Section required one file per side.
Scale is about 17.5 feet over 256 Pixels.
The Horizontal Stabilizer was fit into single texture file.
Scale is surprisingly also 16.64 feet over 256 Pixels.
At this point, there are already 11 Texture files used and another two are expected:
I expect to need at least one more texture file for Flaps / Flap Wells and Spoilers and another for the Control Panel and Armour Plate.
The Top-Bottom and Fore-Aft Textures are much harder to lay out than the Side Textures because they need to be offset slightly so that the shift (smoothing) in the simulator will leave the aircraft with textures aligned on each side.
The Side Textures also shift (Textures are moved forward about 1 to 1.5 Pixels) but the effect isn't as noticeable because it is not asymmetric. This only became very noticeable with the Cowl textures because there was so little clearance to the edges of the texture.
Regarding asymmetric texture shifts, one can offset the panel lines and camouflage in the texture files OR lay out the textures with a built in offset to make for easier painting. The layout is only done once per model, so I believe it makes more sense to do it there. Most of the time, the result is a "very close" rather than "exact" match but the difference is only a small fraction of a pixel in width.
Note that there should be a "No Step" warning on the Red portion of the Side Windows. On this model, the Red Frame is only 3 Pixels wide, so there is no room for any greater detail.
Up to this point, we were doing pretty well as far as build issues other than the earlier Templates problem.
When Textures were applied to the Retracted Flaps, the first model display issue showed up.
Note that not only is there a polygon stretching off to infinity, some of the Cowl parts are missing as well.
The God of AF99 needed a sacrifice.
This version of the Lightning didn't have Dive Brakes and they would not be displayed anyway, so that was the first thing to be deleted. That cured the first issue....
Textures were then applied to the Nose Wheel. A pretty similar problem showed up.
I realised at this point that All of the Wheels required a texture of some kind so textures were applied to the Main Wheels as well. More parts of the Cowl disappeared and the "Infinity Polygon" returned.
Next it was a matter of choosing Pieces to delete that would degrade the appearance of the model as little as possible.
The last screenshot shows the result after deleting the Nose Gear Dampers (which was not enough) and then deleting the Spark Plug Scoops from the Cowl Components.
At this point the exterior has a minimum set of textures. I believe it is unrealistic to have two additional texture files as discussed earlier. I may still try to texture the Control Panel and possibly the Turbochargers and test if those changes cause a display problem.
Iīm pleased to see the continuation of your P-38 Lightning Study. Working near the parts-count limit has its difficulties. Like you, I too have found parts disappearing and additional texturing being blocked, and the only solution is to simplify somewhere - often a difficult decision!
You mention an Infinity Polygon - I wonder if you could explain. Is this something that arises when the AF99 degree of complication is so high that AF99 just chops the script at the end somewhere in the middle of a polygon, deleting the end of its coordinates list?
You see the polygon(s) stretching off into the distance?
I just gave this thing what I thought was an appropriate name. It is hardly a technical term.
I didn't bother checking out what the SCASM code was that was causing the problem because even if I found it, I could not really fix it.
Hopefully the last batch of Parts removals will be enough to let me finish a few more textures.
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