Introduction: It’s Not Rocket Science.

But aircraft design is not exactly like falling off a log either. That’s why the idea of AeroDesigner was born. AeroDesigner allows a 3D visual method of presenting aircraft physics components – and allows these components to be easily modified with a click of the mouse. Mass parameters, for example, like the position and weight of the engine or fuel tank, can be moved by dragging to any 3D point – all the while the CG (center of gravity) is displayed in 3D. Airfoil components can be dragged to their proper points on the model - then oriented, for example, to the proper amount of dihedral. Contact components can be made to correspond exactly to the model’s wheels or skids then given the proper coefficient of friction. Even sounds can be specified exactly in terms of position and orientation, and by specifying the desired .wav file!

And of course, at any point in the design process, you can run the aircraft in PRE-Flight to check out your design in still, or turbulent air, or in a strong crosswind, in simple or complicated manoeuvers.

Apart from designing flying models, AeroDesigner can also produce non-flying models that can be used as parts of a scenery (like trees, buildings, ground features, landscape features, sky features, etc).

Using AeroDesigner: the basics.

AeroDesigner can display and allow changes to 9 component types:

1) Masses

2) Forces

3) Airfoils

4) 3D Meshes

5) Contacts

6) Colliders

7) Winds

8) Views

9) Sounds

All Components are represented by a colored ball. Each component type is distinguished by its color. The center of each ball corresponds to the component’s location (in 3D). Masses, Forces, Airfoils, Contacts and Winds directly affect a model’s physics – the rest affect how the model is presented in the simulator. Components are position-based and are (usually) moveable by dragging with the mouse. Generally, components can be as few or as many of a given type as desired (see below for exceptions). Components of a certain type can be made visible or invisible by checking the component in the Component pull-down menu. All components are identified by a name which is unique across all types in the model and is (usually) descriptive of the component it represents.

All of a component’s parameters can be altered by right-clicking and selecting properties. While all components are represented by a colored ball, not all balls represent components. The CG is represented by a larger yellow ball (visible if Masses are displayed) which cannot be moved directly or edited. Other balls are discussed below.

Component properties (right-click) are normally plain numbers (floating point) which means they are fixed in time and do not vary during the simulation. However, provision has been made in PRE-Flight to allow variable component properties. These look like equations (and usually they are) as opposed to plain numbers and they allow properties to assume a range of values and greatly increase the simulation capabilities of PRE-Flight. Variable properties can usually be substituted for fixed properties in all component types.

A short description of each component follows:

Masses(red) - represent an object in a real model. For example, engine, fuel tank, battery, as well as structural parts like left and right wing, stab, left aileron, etc. The location represents the object’s center of mass. Mass components have only one parameter – weight. A special ball (yellow) represents the Center of Gravity (CG).

Forces(green) – are aircraft components that apply force to the model. For example, a jet engine or EDF (Electric Ducted Fan). This type of force is distinguished from Airfoils (also called WindForces) see below.

AirFoils(blue) – Are basically identical in effect to Forces but are wind-generated (or wind-affected) only. Examples of airfoils are : main wings, tail fins, stabilizer, rotor blades, etc. A special type of "airfoil" is body drag which simulates the drag of the aircraft’s fuselage.

3D Meshes(magenta & orange) – These are the visible parts of the model and has nothing to do with aircraft physics. There are different types of 3D objects that can be used, the main type is the 3D mesh object. This is produced by REALIZE, a 3D editor and texturing program. The other types are "off-the-shelf" 3D shapes like spheres, cubes, cylinders, toruses (donuts), 3D text, and billboards. Photorealistic components like trees use billboards (which look the same in all horizontal directions). Smoke effects use a special kind of billboard called a "3d billboard" which looks the same in all viewing directions, including vertical directions.

Associated with a Mesh component ball is a "scaling ball"(orange). This allows quick and even scaling in all three directions by dragging (instead of tediously doing scaling thru properties).

Contacts(cyan) – Define four(no more, no less) points of ground contact for the model. The locations for these contact components are restricted to mutually co-planar positions only – hence dragging is somewhat restricted.

Colliders(white) – define "areas of collision" in the shape of spheres. Any collisions with the ground or any other collider sphere of any other model will result in the simulation being terminated with a message associated with the collider.

Winds(orange) – Define cylindrical volumes of wind (such as one may expect from a propeller) which may interact with Airfoil components of this or other models. Wind components are sometimes used in conjunction with Airfoil components to simulate the action of propellers, rotors, and other rotating, windforce-creating objects.

Views(white) – Define aircraft views that PRE-Flight can show – cockpit view, chase view, wing view, etc.

Sounds(black) – Define aircraft sound(s) that may be defined as directional. PRE-Flight presents these sounds as fully 3D with directionality, distance attenuation, and Doppler effects.

Airfoils and Winds.

These two components are the most sophisticated and most involved of all the components. These two components are sometimes also partnered together(one each) to produce rotor and propeller simulations. In this case, dragging one component also drags the linked component with it.

Rotating airfoils like propellers and rotors are simulated by a fixed airfoil and an associated(linked) wind component. A propeller blade, for example, is not whirled around to produce the necesary force. Rather, the blade, represented by an airfoil, is fixed, and a wind component (equivalent to the wind the blade would experience if it was whirling around), is applied. This results in the same forces being produced it the blade were actually rotated while requiring much less computer power to simulate. The same is true for helicopter rotors.

3D Meshes.

Due to the enormous "fun potential" of this component, it has been given its own section. A short mention of how 3D meshes are produced and textured is in the AeroModeller Tutorial. This section explains more of what 3D Meshes are, how they are produced, and what they are capable of doing.

3D meshes are usually produce by 3D editors - making these by hand is possible but very tedious. PRE-Flight meshes are usually made using a freeware editor called Blender. Blender meshes are built from blueprints (front, side, and top views of a desired model) and are exported to .dxf format. The freeware program REALIZE is then used to add texture and sometimes do further 3D editing to the model. Special texture effects like transparency and reflection are added by REALIZE. Finally, AeroDesigner is used to add the completed 3D mesh or meshes to the flight model description (.3dm file) along with the models physical description. PRE-Flight is then used to fly and check the model.

It is possible in the .3dm file to animate the 3D meshes to produce, say, control surfaces that move in response to the joystick controls. This is possible using varying values of a mesh's position, scale, and rotation. Propeller simulation, for example, is done by rotating a mesh.

A mesh can be "turned off" or hidden by using the "Condition" parameter. The propeller animation is a good example of this technique. At low speed, the propeller blades are rotated, while at higher speed, they are hidden and the propeller disk is activated.

"Spawning" an entire model (.3dm file) can be specified in a model. A good example of this is smoke. A puff of smoke is actually a small model which is a 3D billboard and has limited physics (so it can be blown about by the wind). A puff of smoke is also given a limited lifetime so that it disappears from the scene after a while. Spawning can also make missiles and bombs possible.

Other 3D Objects.

There are a number of other "off-the-shelf" 3D objects that can be generated by PRE-Flight without using 3D meshes. These are as follows:

1)Billboard - specify a .bmp or .tga(transparency is supported) file. A billboard looks the same from all horizontal angles. A good example would be trees and pictures of your friends.

2)Billboard 3D - as above but looks the same for all horizontal and vertical angles.

3)Billboard Static - as above but does not rotate to face the viewer. Put 5 or more of these together(with different texture files) to produce a box-like structure (like a building). Also see the fence in the heli scenery...

4)Box, Cylinder, Polygon, Sphere, Teapot, Torus - creates these 3D objects. Try them.

5)Text - creates 3D text. Try using, say, the "Wingding" fonts to create objects more interesting than plain letters - but make sure that the user of your model file has these fonts available in his/her PC. Otherwise they see nothing.

Items 4 and 5 are colorable but all are textured plainly - advanced texturing(like transparency, etc.) is possible only on 3D meshes.