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Hovercontrol Bell 412 Helicopter Design Diary

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For me, the process of choosing my next helicopter to design is not that scientific. Basically, I just wait until I am fully enthusiastic about a particular model. At the time I chose to start work on the Bell 412, I had recently completed the Hovercontrol Blackhawk. The 412 was actually not on my mind. I had started dabbling with a few ideas, and for some reason pictures of the 412 kept popping up, and grabbing my attention. I had been wanting to update my Huey package, and since there continued to be shortage of freeware 412s to choose from, I eventually came to the conclusion that it was a good choice. As soon as I started working on some basic modeling tests of the 412, I realized this was a helicopter that I could get very exited about. This helps when the hours of design work start to rack up, and inspiration is hard to find!

First shot of project! Just hours after deciding on the 412 as a subject.

The shot above shows the very first screenshot of the project. Typically I will start a project by fiddling around with the basic design of the fuselage. This helps me get a feel for the personality and shape of the aircraft. I don't consider any of the modeling permanent at this point, it is mostly to begin familiarizing myself with the model and to help show me what road blocks might lay ahead for this particular design. I was excited right away with the 412, because I could see that the shaping would come along quite nicely, and that the main fuselage components would not present many huge design challenges. Freeing me up to take more time on the details, and tidbits.

A brief test of textures using some photos found on Airliners.net as a basis for the texctures.

One of the next initial tests I do is start examining how the textures will be applied, and how they will look. This also begins to prepare me for any of the challenges that I might be faced with in the future of the design. Using some basic photographs found on Airliners.net, I was able to throw some photo-realistic textures on the model. These would not be used for the final project, but are quite helpful to begin understanding where the textures will lay, and where certain other parts might be positioned.

High quality technical line drawings are usually best when considering a source reference for modeling. However these have to be reviewed carefully to make sure that they were not drawn by an artist. No matter how good the artist, hand-drawn line drawings tend to lead to strangely shaped models. If I can't find good tech line drawings, I will opt for photographs instead. However, photographs come with their own set of challenges. Most importantly, it is difficult to find photographs that are taken from straight angles. In addition to this, all photography includes perspective and lens-angle challenges. For example, objects that are further away in a photo tend to appear smaller. However, if you model them smaller, they will be inaccurate. So it takes some practice to learn how to accomodate for this in the modeling tool.

First shot of the 412 imported into the simulator. A success, but a long way to go!

Above is the first screenshot taken with an import test of the model into the flight simulator. This is always an exciting time, when you first get to see your project in the sim. Of course, the excitement doesn't last long, because nothing is animated, contact points are all wrong, lights are not positioned, and flight dynamics don't match the aircraft! Never the less, the model has come to life, and its fun to enjoy the feeling while it lasts.

First photo including internal seating and sound proofing padding.

This photo shows the beginning of the internal modeling. Beginning with the seats that were modeled using a photograph of a helicopter seat at Heli-Expo 2004 in Las Vegas. It was convenient to have a seat sitting by itself, outside of any aircraft. It can be challenging getting good texture photos of objects such as seats. You can also see that some of the main fuselage parts have been cut to have textures on all sides. This will give repainters the full control that they desire later on. Instead of having textures that wrap around the fuselage leaving repainters with only portions that can be redone. This process takes some extra time, but I'm sure they will appreciate the effort. Its important to no start splitting the parts for textures like this, until you are quite sure that you won't be manipulating, or reshaping the part again in the future.

I like to think of the design as a house of cards, where the first layers have to be set quite correctly. Everything else you design will rest on the layers (or parts) that have come before. So if you start with a few strange or inaccurate parts, everything you do after that point will get more and more inaccurate. This will be especially frustrating when you go to view your finished design, and everything seems to look a little "off". At this point there will be little you can do about it. Its better to take each step as slowly and carefully as possible as you go-along. Make sure you are happy before moving on to the next part!

First photo showing transparent windows, created by using transparent drawn-on windows.

Finally reaching the point where the transparent windows can be used/shown is also quite exciting. You might notice on my design I choose to use windows that are simply drawn onto the textures. I use transparent alpha sections on the texture where I want the glass to be. Not everyone chooses to design this way. Especially those using Gmax. In gmax their are tools for cutting sections out of existing parts, however FSDS does not have this option. In addition to that challenge, I choose this method because I can draw on detailed windows without paying any price in polygons. So for example, the windshield section in this 412 might only have 10-12 polygons. A design that uses a fully cut-out windshield could easily consume 100-500 polygons. This also leaves me with sections of the fuselage that will look very thin, so later on I will go back in and add parts where they are needed to give the appearance of thickness in the fuselage. This is my process, but not everyone chooses to take the same route.

First virtual cockpit test in the simulator. Very simple modeling, and basic texturing.

Above is the first screenshot I had taken of the virtual cockpit area being tested in the sim. There really isn't a lot going on in this picture. For example, the panel is simply a photograph, and not a thing is animated. I just wanted to see it, because I had been working on the external portions of the helicopter for so long. Its good to get a sneak peek at how things are going to lay out in the virtual cockpit. This can help you foster ideas as you get back to work on the external sections. It also helps make sure that the basic components like the pilot's seats are situated correctly. As I mentioned before if the seats are in the wrong place, and you start adding all sorts of other parts around them, eventually you'll end up wondering why everything is a little "off". So typically I place a few items as a good reference for everything else. These "reference" items get a lot of my attention, to help avoid position and scale problems later.

First collection of shots showing progress of the external modeling.

You might notice that a lot of colors have been showing up on the aircraft up to this point. This is because a great deal of my time has so far been put into creating a texture kit that makes it very easy to change the colors and layout without disrupting the details. So to help fight off the boredom of long hours designing, I would occassionally try out different paint jobs. This also helped me establish my ideas for what the first "official" paintjob might be. The screenshot above was one of the first collage shots, showing the various external viewpoints of the aircraft. I had been experimenting with dark gray/green colors to see how a semi-military looking version of the helicopter might appear.

One of the trade-offs I take by using transparent textures to create the see-through window sections, is that I can not use the alpha channel of the textures to control reflectivity. I choose to add a little specular lighting to the model instead. This gives the impression of light reflecting off various surfaces. Its not quite as impressive as reflective textures, but it does the trick. In my experience, it is also a little friendlier for mid-level computers in terms of performance. Reflective textures take some additional processing power to handle. I certainly don't disagree that they look great.

First photo to include stationary rotor blade modeling. Main and tail.

Finally! The moment of truth. This is when the 412 first got its solid blades and rotor head. The rotor head and blades can take a fair amount of time and research to get right. Because of the rotor head complexity on helicopters, this is also an area where a designer has to make a good balance between detail and performance. In addition to these factors, the rotor head has too look good when it is animated for spinning. The 412 has a very cool rotor head made of two overlapping rectangular plates. One of the things I like best about designing new helicopters, is the research I get to do on the helicopter I am working on. I feel that learning more about the helicopter really helps boost my appreciation for the particular aircraft.

In addition to rotor-head modeling, giving the rotor blades a certain amount of personality takes some work as well. Its important to remember that rotor blades droop in unique ways depending on the helicopter, and its important to examine as many pictures as possible to get a feel for this characteristic. This is where the personality of the aircraft will really come through. Rigid rotor blades, that hang to "straight" can give your design a sterile look. Making them droop too much on the other hand, or droop in the wrong places, can give it a "broken" look, that will make people want to take it to the virtual repair shop and get new blades!

First photo showing animated transparent blade parts.

Its interesting that most people would think that the spinning blades are probably an automatic byproduct of animating the rotorblades. Unfortunately they must be designed from scratch, and normally this process is entirely different than modeling the static version of the rotor blades. I prefer to use transparent disks covered with transparent textures to achieve a spinning rotor effect. I like to avoid spinning blades that cast shadows on the ground, as well as any solid blades as part of the transparent disk. In my design the solid blades are only seen when the rotor disk has slowed down, and is coming to a stop. Having too many solid parts included in the spinning animation also takes a larger bite out of system performance, and lower-end machines will suffer if this isn't kept to a minimum. The only complicated part that I will include in the spinning animations is the rotor head. Because the rotor head is fairly poly-heavy, I try to make this the only part that will be seen in a "solid" way during the spinning animations.

Emergency floats have been added, and animated.

With the blades modeled and animated. I am able to move on to some additional external modeling and animation. My next step was to include a custom emergency float kit. I thought it was only fitting, as this first 412 model will be an off-shore support type variant. In order to give the impression of floats that inflate quickly, I used the tail hook animation sequence. Flight Simulator does not support "scaling" animation. By this, I mean that you can not animate parts getting bigger and smaller. You can move them, or rotate them, but they can't shrink or grow as part of the animation. I worked around this limitation slightly by creating several sets of floats. Starting small (uninflated), then getting larger and larger with each set, until the final set is the full sized version. Then I hid the floats in an internal portion of the airframe. Directly behind the Main rotor gearbox, just behind and below the main rotor shaft. As the tail-hook is extended, the various sets of the floats appear in rapid succession. Creating the illusion that they get bigger quickly. The process is automatically reversed, when the tail hook is retracted. Its not as ellegant as I would like, but it beats simply having the floats appear/dissapear all at once.

A virtual cockpit photo taken in the sim after extensive internal modeling work.

At this point, much of the external modeling, including the small lights, and hydraulic lines for the floats have all been complete. There is some left to do, but not much. So I turn my attention back to the internals. Specifically the virtual cockpit environment. The screenshot you see above still uses a simple photograph for the panel, but as you can see there is a significant amount of new modeling. I have completed the cyclics, the collective, the foot rests, center and overhead consoles at this point. I have also added quite a lot more hand-drawn detail to the textures that cover the internal sections of the fuselage and overhead panels. You can begin to see more shading on the textures, as well as a shade strip at the top of the windshield. The remainder of the windshield when looking out from the inside will be perfectly clear. Friends don't let friends shade windshields on the inside! If you are thinking about desiging a helicopter, please consider this. Looking out through a shaded windshield while in the virtual cockpit mode can get quite annoying after a few minutes in the sim. For some people it will cause headaches and dizziness. Not kidding.

A recent picture showing the 412 with pilots, taking off in front of AI traffic!

Finally, someone to fly the aircraft! In the shot above the pilots have finally been added to the aircraft. I originally thought I would design the pilots from scratch for this project, but after comparing the scratch built version against the pilots that I have used in the past, I decided that the old pilots simply look better. So I went with them again on this project. These pilots are created using Dave Eckert's freeware pilot model, textured with my own textures. Scaling and positioning the pilots in your aircraft design should not be taken lightly. This is an area that can really help your design look realistic...or take away from its realism. There are many great helicopter designs existing today that have wonderful modeling, but the pilots are not to scale. Leaving a helicopter that looks like it is being piloted by tiny people, or the opposite, where the "giant" pilot looks as if he was squeezed into the cockpit. Like the rotor blades, the pilots should get a little personality. Perhaps a little twist in the seat, or head cocked to the side. Use your imagination. For fun, compare the pilots in the default Robinson R22, to real photographs of the same helicopter, and you will realize that even the MS design team sometimes get the scaling wrong. My advice is to play with the pilot models for a while, and continue to tweak them and scale them until you are completely happy. Compare them with as many real photographs as you can find. Space is a premium in most helicopters, and typically the pilot takes up a lot of room in the cabin area.

Everyone has to find the tools, techniques, and processes that work for them. Creating a helicopter from scratch is a long and complicated process, so there is much room for individual design styles. One of the best things a designer can do is to study the work of others, and learn from what they see. Look at all the details, and challenge yourself to understand how the designer achieved the effect.

The tools I choose for now are:

FSDSv2 from Abacuse Software Photoshop from Adobe FS Panel Studio NoteTab Light (a replacement for text pad in MS).

This will probably be my last full scale design using FSDSv2 from Abacus. It is a great tool, but the future of FS is not leading in the FSDS direction, and as skills grow, the more powerful shaping capabilities of Gmax, 3DS Max, and Rhino become more and more appealing.