The template concept


This section will help you to get accustomed with the template concept. During this "training" session, you will be prompted to perform some operations which are quite useless... Sorry guys! It won't be that bad.

Templates are polygons with special features. The templates are stored in template classes. The templates of a class share some characteristics which allow for automatic generation of polygons. There are three kinds of template class:

Section classes are convenient to design a fuselage, or an engine nacelle. Half-section classes are used to design a canopy or the intersection of an engine nacelle with the wing. Profiles are dedicated to wings or stabilizers.

Create a template

To create a template, you need to create a template class. Select the Template/New class menu option. The class creation panel is displayed on the right part of the screen.


Look at the proposed options, I suppose you will understand them easily. Select the default option: section, 12 vertices, xOz plane. You need to enter a class name (alphanum, 8 characters). You may also enter the coordinates of the origin of the first template of the class in the input fields at the bottom of the panel.

You need then to set the class parameters which define the shape of the class. You will do that by editing the first template of the class. Click on the set parameters button (with a big green dot on it). It will activate the template editor panel.

The Template editor input panel is composed of five parts.
(1) At the top of the panel, the height and width of the template (or chord and thickness) are displayed and can be edited.
(2) Below these two input data fields, a graphic window displays the shape of the template with the current settings. Another template of the same class can be displayed at the same time (it is drawn in fuchsia). A bar just below the graphic window controls the display of the reference template.
(3) In the middle of the panel, two adjustable bars (or one in case of a half-section) allow you to modify directly the settings of the template without manually writing the values of the parameters.
(4) The parameters of the template are displayed and can be edited on the sub-panels in the lower part of the input panel. There are two sub-panels in case of a section template. To display the sub-panel dedicated to the lower part of the template, click on the Lower parameters thumbnail. To display the sub-panel dedicated to the upper part of the template, click on the Upper parameters thumbnail. There is only one sub-panel in case of a profile template or in case of a half-section template.
(5) To cancel or validate the input, click on the cancel or the OK button at the bottom of the panel.

The sides of the templates of a class are making given angles defined at the creation of the class. You may modify the class angles in the edit panel when you are creating the first template of the class. Then, it will be no longer possible to access them. The length of the sides is specific to each template. You can also modify it from the template editor panel, either by editing the coefficient input fields in the parameter sub-panel or by dragging the small vertical lines in the upper and lower bars just below the template display window (the white one). You can switch from the upper parameters sub-panel to the lower parameters one by clicking on the thumbnails of the parameter panel. The picture hereafter illustrates the meaning of the section class coefficients.


Validate your settings: click on the OK button of the template editor panel, then click on OK button of the class creation panel. You have created your first class and its first template.

Create another template

You can either select the Template/New template menu option or click on the priority template button on the tool bar and then click on the fourth button of the tool bar. A new panel is displayed at the right of the screen.


A combobox can be seen at the top of it. It allows you to select the class to which you will add a new template. At the moment, there is only one class available. Enter the coordinates of the origin of the new template. Please, give it a "y" coordinate different from the "y" coordinate of the template you created a few seconds ago. You can also edit the height and width of the template. Give it a 7.000 height and a 5.000 width. As it is a section template, you will have to edit the coefficients of the template before you validate its creation. Click on the edit button. The template editor panel is displayed, but you will notice that you can no longer modify the angles. You can also notice that you can display the image of the first template of the class by clicking on the see button below the template display window (actually, you can display the image of any existing template of the class by clicking several times on the arrow buttons, but at the moment only one is available). Select the coefficients you want and validate the creation by clicking on the OK button of the template editor panel, and then on the OK button of the template creation panel. You have created your second template.

Template ties

Templates can be tied to each others. This creates a dynamic relationship between a child-template and its parent-templates. The following example will help you to understand the concept of template ties.

Create a third template. Please assign it a "y" coordinate which is different from the "y" coordinates of the two already created templates. In the template creation panel you can see that the tie button is now enabled. Click on it. The template creation panel is modified and gives you more options.

These options allow you to align the template with two other templates of the class. The parent templates can be selected by clicking on the Up/Down buttons besides the rows displaying the coordinates of their origin. The association of a coordinate row with an Up/Down button is a convenient way to select a template among the list of templates available for a given class. It is often used within the template creation/edition and cover panels. At the moment, there is no choice since there are only two templates available.

There are four kinds of alignment ties:

Selecting an option will disabled some input fields (you can no longer modify the width of the template if you have selected the width alignment option, for instance). Select all alignment options, edit the template to set its parameters and then validate the creation.

The alignment ties are dynamic links. Edit the first template of the class: select the Template/Edit menu option. A new panel is displayed at the right of the screen. It looks like the template creation panel but it offers more options. The coordinates of the origin of the selected template are displayed. We don't want to edit this template but the previous one in the class list. Select it by clicking on the Up/Down button besides the coordinate row. Modify its height and width. Validate. You will see that the height and width of the child template are modified automatically.

Cover templates

The template concept is useful because it allows you to automatically generate surfaces. This is the purpose of the Template/Cover menu option: select it. Another panel is displayed at the right of the screen. You will recognize a class selection combobox and template selection coordinate rows. Select the cover section option (radio-button) and then select two templates by clicking on the Up/Down buttons... Validate (cover button). Aircraft Designer 2000 will automatically generate the polygons covering the part comprised between the two templates. Now, if you edit one of these templates (modify the height, for instance), you will see that the polygons will reflect the modification once it is validated.

Profile class

You can do the same thing with a profile class. There are three profile types which are illustrated by the following figure.


The creation process of a profile class is similar to the creation process of a section. Of course, the meaning of the coefficients is not the same.


Editing a template, you will notice a few differences. For instance, you can no longer access the coefficients of the templates once the class is created.

Create a profile class parallel to the yOz plane. Create several profiles in this class. Enter a different abscissa for each profile. Activate the cover mode. Four options are proposed. Two of them allows you to automatically build wing tips. Try the wing tip / simple option. Clicking on the sample button displays a window giving information on the required parameters.


Be cautious: the order of selection of the templates is important. The wing tip will be built on the second one. Validate. Look at the result in the 3D view mode. You can change the angle of view in the 3D view mode by hitting the q key of the keyboard or the Q one.

Go now to the front view mode. We shall modify the dihedral angle of the wing. Click on the Priority template button in the tool bar. You can now select a template by clicking on one of its vertices. Select one of the profile templates supporting the wing section you have just created. Click on the edit button of the tool bar (the fifth one). Because we are in the Priority template mode, it will activate the template editor. You can modify the "z" coordinate of the origin of the template in the appropriate input field of the panel. You can also relocate the origin by clicking on the navy-blue window. A red cross shows the new location of the origin. Move it and click on the confirm button. If you are not happy with the new location, you can click on the retrieve button... but if you do that you will see no difference on the wing tip! Validate the modification (OK button). You can see now that the wing tip is modified accordingly.

The wing tip building process is based on vectors. To modify it, you must edit the vectors. Go to the Utilities menu and select the Show vectors option. The vectors are now displayed by red lines (dotted or solid). To cycle through the list of vectors, you just have to give the blue-navy window the focus (by clicking on it) and press the v or V key several times. To modify the currently selected vector, select the Utilities/Edit vector menu option. Play with it to get accustomed and understand the way it works.

Special feature of the profile templates: The trailing edge of a profile template is composed of two vertices at the same location. Therefore, there is no texture smoothing at the trailing edge and it looks sharp.

The half-section class

The half-section class is useful to build a canopy or the intersection of a prop engine with the wing. The Tie option does not tie a half-section to other half-sections of the same class as with section classes and profile classes. It ties it to section templates. One can tie a half-section template to a single section template or to a pair of section templates. One can make a half-section to be tangent to its parent section template(s). All these features are used to automatically generate the intersection of a canopy with the fuselage.

Create a 14 vertices section class in the xOz plane and populate it with two or three templates. Keep a distance of 5 ft between each of them. Then create a top half-section class. Edit the first template of the class. Click on the Tie button: a combobox is displayed in the lower part of the panel as well as one or two coordinate row(s) to select the parent templates.


We shall align the template with one template of the previously created section class. Select the section class in the lower combobox, select the tied to a single template option and do not select the tangent option. Select the parent template by clicking on the Up/Down button besides the coordinate row. In the front view, you can locate the origin of the half section (red cross in the blue-navy window) by clicking inside the parent template. Modify the scale of the display window to feel more comfortable (lower-right part of the screen). Actually, the red cross remains in a very narrow band delimited by the upper and higher extremities of a pair of sides of the section template. You can move the cross in a band defined by another pair of sides by clicking with the right button of the mouse. Validate the edition.

Create another half-section template tied to another parent template of the same section class (same options). Validate. Then, create a third one between the two previously defined parent templates and tie it to these two parents: this time, do not select the tied to a single template option. Make sure that you select the right parent templates. Validate.

Now you have the elements required to automatically generate the intersection of a canopy with a fuselage. Select the Templates/Cover menu option, select the half-section class in the combobox and select the combined cover option.


The templates available for such a cover automatic process are displayed below (two coordinate rows). Select the two single parent half section templates. Click in the intermediate option checkbox: the third half-section template is now made available for the combined cover and appears in a third coordinate row. Validate by clicking on the cover button. Aircraft Designer 2000 automatically generates the intersection of the surface built upon the half-section templates with the surface built upon the parent section templates. The canopy part is stored in the multiple selection buffer and can be easily transferred to another sub-assy.

You can try again and use one tangent half-section template.

Advanced option: wing/fuselage intersection

Clear the project by starting another one (File/New menu option or first button of the tool bar). Create a sub-assy. Create a 14 vertices section class in the xOz plane (default plane):

Create a profile-section class in the yOz plane (default plane): Select the template/intersection menu option, click in the 3-profile checkbox.

Click on the Up/Down button associated to the base profile coordinate row in order to bring the 0.000, 0.000, 0.000 profile on display.

Click on the Up/Down button associated to the intermediate profile coordinate row in order to bring the 3.000, 0.500, 0.000 profile on display.

Enter 0.200 as intermediate lift coefficient and validate (OK button). Aircraft Designer 2000 will automatically generate the intersection between the fuselage and the wing.




copyright Hervé Devred, 2001