Tutorial : Section 6


The fore section

new concepts : enlarge a chain - use the space bar in the multiple selection mode - JUMP PROP instruction

The fore section includes the propeller and the fuselage part which covers the engine. The fuselage part generation does not bring any new concept. Create a new sub-assy called "ForeFuse". Activate the Template|Cover template menu option. Make sure the selected class in the input window is the "Fusetemp" class : if not, select it. Use the default cover section option. Use the Up/Down arrows beside the 3-coordinate rows to select the templates the origin of which are located at :

 -0.000 2.400 -2.300
-0.000 7.300 -1.700

This time, the order does not matter. Validate by clicking on the cover button.

Activate the Template|Cover template menu option again. Select the cover selected template option. Select the template the origin of which is located at :

 0.000 7.300 -1.700

Mak sure the Fore button is pressed. Validate by clicking on the cover button.

Launch the Model Editor and display the code page associated with the FOREFUSE sub-assy. You will recognize the polygon that was created just before at once : it is a 12-side polygon. Select the declaration instruction which is related to it and insert a GCOLOR instruction with the grey color (index #2). The 12-side polygon must be transformed into a "Gouraud" shaded polygon (GPOLY). You know how to do this... Go up to the beginning of the list and select the first TPOLY instruction. Insert a TEXTURE/LIMITS combined instruction pair. Assign the "forefus" file to the TEXTURE instruction with the full and side attributes. The texture support was already used a few times ago (MIDFORE sub-assy). Click on one of the blue-green arrows in the texture selection window to have the following limits displayed in the texture selection window :

ymin, ymax :  -2.400  7.300
zmin, zmax :  -2.500 1.500

This is it with the fore part of the fuselage.

the propeller

Exit the Model Editor. Create three sub-assies called respectively "aftprop", "proprun" and "foreprop". AFTPROP will contain the prop root and the blades when they are visible (no speed or low speed). PROPRUN will contain a transparent disk representing the prop at high speed. FOREPROP will contain the tip of the prop. The model will be simplistic : we do not want to make a collection model, we just want to learn how Aircraft Designer 2000 works.

Select the Desk. Select the front view and click on the sel button of the tool bar. Click on a point located at :

x = -0.330 z = -1.700

This an existing point. This will result in the y coordinate of the current screen plane to be setted at 7.300 (check that this is the case in the plane data field in the lower right corner of the screen). As the Desk is the only one sub-assy selected, it is still the currently selected sub-assy.

Activate the Draw|Shape|Hexagon menu option. The front option is the default option. Enter the coordinates of the center of the hexagon in the relevant input data fields :

0.000 7.300 0.000

Enter the number 0.800 in the radius input data field and validate (draw button). Then activate the Draw|Build a cylinder menu option. Select the AFTPROP sub-assy as the destination sub-assy. Enter :

0.000 0.600 0.000

in the input data fields of the coordinates of the vector. Validate by clicking on the build button.

Make sure the Desk is still selected. Click on the c key (the "small" one : capital-C makes you go back in the list, small-c makes you go forth) in order to highlight the polygon that was created by Aircraft Designer 2000 to build the cylinder. All the vertices of this polygon are on the y = 8.000 plane. Select the Draw|Enlarge menu option and enter the number 0.850 in the enlarge factor data field. Validate by clicking on the enlarge button. You can see that the given polygon was shrunk by this operation and that all the AFTPROP polygons were modified in accordance.

Stay in the Desk sub-assy and activate now the Draw|Build cone menu option. Select the FOREPROP sub-assy as the destination sub-assy and enter :

0.000 0.800 0.000

in the input data fields of the coordinates of the vector. Validate by clicking on the build button.

We shall assign a color to the propeller gear cover. Launch the Model Editor and display the code page associated with the AFTPROP sub-assy. Insert a GCOLOR instruction at the beginning of the code list. Assign it the red color (index #5). Transform all the TPOLY instructions into GPOLY instructions. Do the same thing with the FOREPROP sub-assy.

The AFTPROP sub-assy will also include the blades. Let us assume the "Ugly100" propeller is a twin-blade one.

Exit the Model Editor. Select the AFTPROP sub-assy and the front view. Click on the sel button on the tool bar. Adjust the scale factor to a value that will make you feel more comfortable. Click on the point located at :

x = -0.590 z = -0.340

This is just a way to select the y = 8.000 screen plane. Activate the chain creation mode. Create a polygon with the following vertices :

0.590 8.000 0.100
  1.100   8.000 0.260
4.260 8.000 0.340
4.500 8.000 0.000
4.260 8.000 -0.340
1.100 8.000 -0.260
0.590 8.000 -0.100

Validate by clicking on the poly button.

Reset the multiple selection buffer (eighth button of the tool bar). Activate the multiple selection mode (ninth button of the tool bar). Press once on the space bar. The polygon that you have just created and which is the currently selected polygon is stored in the multiple selection buffer. Is is displayed with a green line. Unselect the multiple selection mode without resetting it. Duplicate the blade polygon (Draw|Copy/translation menu option with a 0.000, 0.000, 0.000 vector) and flip it (Draw|Flip menu option). Activate again the multiple selection mode and press once the space bar. The polygon that you have created as a copy of the previous one is also stored in the multiple selection buffer. Activate the Selection|Mirror|right/left menu option to generate the other blade..

Launch the Model Editor and display the code page associated with the AFTPROP sub-assy. The four last polygons in the list are the four polygons that we have just created to represent the blades. These are TPOLY type polygons at the moment. Click on the first of them and insert a GCOLOR instruction and then a RETURN instruction. By doing this way, the RETURN instruction is just before the GCOLOR one. Assign the black color (index #0) to the GCOLOR instruction. Transform the two following TPOLY instructions into GPOLY instructions. Give the "BLADE1" label to the GCOLOR instruction.

Select now the first of the two remaining TPOLY instructions and repeat the operation we just did before. This time, give the "BLADE2" to the GCOLOR instruction.

We still have to generate the code related to the AFTPROP sub-assy. Go to the beginning of the code list and insert two JUMP PLANE/GOSUB.../RETURN instruction blocks (SHIFT+INSERT). To define the seal planes, we have to exit the Model Editor and go back to the Aircraft Designer 2000 main screen. Make sure the AFTPROP sub-assy is selected and press the C key as many times as needed to highlight the polygon on the right side of the prop gear cover. Declare it at a seal plane. Launch again the Model Editor and display the code page associated with the AFTPROP sub-assy. Assign this seal plane to the first PLANE instruction. Repeat this operation with the left side of the gear cover and the second PLANE instruction.

Complete the destination addresses of the GOSUB instructions to get the following instruction list :

JUMP PLANE   AP10
PLANE -1.756;-0.989,-0.147,0.000
GOSUB BLADE1
GOSUB AP01
RETURN
AP10      GOSUB AP01
GOSUB BLADE1
RETURN
AP01 JUMP PLANE AP11
PLANE -1.756;0.989,-0.147,0.000
GOSUB BLADE2
GOSUB AP03
RETURN
AP11 GOSUB AP03
GOSUB BLADE2
RETURN
AP03 GCOLOR 5
GPOLY 4;...
...

This is not exactly what we want : we would like the blades no to be displayed when the prop is moving fastly. Select the JUMP PLANE instruction at the beginning of the list and insert a JUMP PROP/RANGE combined instruction pair (Jump and Jump on Prop options in the instruction selection window). Have the JUMP PROP directed toward the AP03 address. The instruction list should now look like this :

AFTPROP   SUBASSY,T   click to come back
JUMP PROP AP03
RANGE 0,60
JUMP PLANE AP10
PLANE -1.756;-0.989,-0.147,0.000
GOSUB BLADE1
GOSUB AP01
RETURN
AP10 GOSUB AP01
...

The prop disk

Generating the prop disk is an easy thing. A 12-side circle will do the job. Exit the Model Editor. Select the PROPRUN sub-assy. Make sure you are in the front view and that the current screen plane is the y = 8.000 plane.

Activate the Draw|Shape|Circle (12) menu option. Enter the number 4.500 in the radius input data field and validate. Duplicate and flip this polygon. Launch the Model Editor and display the code page associated with the PROPRUN sub-assy. Make it a "SUBASSY,S" type sub-assy. Insert a GLASS instruction with the index #8 just before the list of polygons. Give the "PROP" label to this GLASS instruction. Insert a RETURN instruction and a JUMP PROP/RANGE combined instruction pair before it in order to get the following instruction list :

PROPRUN   SUBASSY,S   click to come back
JUMP PROP   PROP
RANGE 0,60
RETURN
PROP GLASS 8
POLY 12;...
...

Fore section associated code

new concept : the RUNPROP instruction

Everything is in place to generate the code associated with the fore section. The logical breakdown to be used is described here after :

FORSECT :  position of the observer with respect to the plane y = 7.300
side#1 : first display the prop (F01) then the fuselage fore part (FOREFUSE)
side#2 : first display the fuselage fore part (FOREFUSE) then the prop (F01)
 
F01 : position of the observer with respect to the plane y = 8.000
side#1 : first display the prop fore part (F02) then the root(F03)
side#2 : first display the prop root(F03) then the fore part (F02)
 
F02 : position of the observer with respect to the plane y = 8.000
side#1 : first display the disk (PROPRUN) then the tip (F04)
side#2 : first display the tip (F04) then the disk (PROPRUN)
 
F03 : display AFTPROP if the prop is moving fast
if not, apply a rotation to it depending upon the prop position
(the RUNPROP instruction)
 
F04 : display FOREPROP if the prop is moving fast
if not, apply a rotation to it depending upon the prop position
(the RUNPROP instruction)

This will lead to the following code list :

FORSECT   JUMP PLANE   F10 //fore section
PLANE -7.300;0.000,-1.000,0.000
GOSUB F01 //prop sub-section
GOSUB FOREFUSE //fore part of the fuselage
RETURN
F10 GOSUB FOREFUSE //fore part of the fuselage
GOSUB F01 //prop sub-section
RETURN
F01 JUMP PLANE F11 //hélice sub-section
PLANE -8.000;0.000,-1.000,0.000
GOSUB F02 //prop tip and disk
GOSUB F03 //prop root
RETURN
F11 GOSUB F03 //prop root
GOSUB F02 //prop tip and disk
RETURN
F02 JUMP PLANE F12
PLANE -8.000;0.000,-1.000,0.000
GOSUB FOREPROP //prop tip
GOSUB PROPRUN //prop disk
RETURN
F12 GOSUB PROPRUN //prop disk
GOSUB FOREPROP //prop tip
RETURN
F03 JUMP PROP AFTPROP //jump if the prop is moving fast
RANGE 0,60
RUNPROP AFTPROP
VECTOR 0.000,0.000,0.000,0.00,0.00,0.00
RETURN
F04 JUMP PROP FOREPROP //jump if the prop is moving fast
RANGE 0,60
RUNPROP FOREPROP
VECTOR 0.000,0.000,0.000,0.00,0.00,0.00
RETURN

You should be accustomed now to generate this kind of code section : please refer to the tips that help to work efficiently and that were presented in the beginning of this tutorial. The "fusetemp" template located at y = 7.300 will be used as a seal plane, as well as the prop disk which is located at y = 8.000. To create the JUMP PROP instruction, use the Jump and Jump on Prop options in the instruction selection window. To create the RUNPROP instruction, use the misc. advanced and Run PROPELLER option in the instruction selection window. We shall also create a null vector (0.000, 0.000, 0.000 coordinates) to complete the VECTOR instruction.

Why are whe applying the same rotation to the FOREPROP sub-assy as we do to the AFTPROP sub-assy ? Just because we want to avoid unpleasant transparencies at the junction between both sub-assies when the prop is running.

To end up with the 3D model

To complete the main code page, we just have to insert a JUMP PLANE/GOSUB.../RETURN instruction to handle the sorting process between the fore section and the remaining of the aircraft :

UGLY100   MASTER
JUMP PLANE   C02
PLANE -2.400,0.000,-1.000,0.000
GOSUB FORSECT
GOSUB C03
RETURN
C02 GOSUB C03
GOSUB FORSECT
RETURN
C03 JUMP PLANE C01 //this part of the code is already generated
PLANE -8.000,0.000,1.000,0.000
GOSUB AFTSECT
GOSUB MIDSECT
RETURN
C01 GOSUB MIDSECT
GOSUB AFTSECT
RETURN
FORSECT JUMP PLANE F10
PLANE -7.300,0.000,-1.000,0.000
...

The "fusetemp" template located at y = 2.400 will be used as the seal plane. This is it : the model is completed. Compile it and save your job. You can now try it... and adjust its flight model.

A few words about 2000

Flight Test 2000 was designed to create and edit the flight model of the aircraft created with Aircraft Designer 2000. We shall not explore all the features of Flight Test 2000 : there is a Help file that you have access to directly from the Flight Test 2000 menu. Until now, you have used the "Ugly100.AIR" file which is available in the "Tutorial" directory to try the model. As you may have noticed, the flight model which is defined by this file is really bad. We shall try to improve it.

Run Flight Test 2000. Activate the File|Open menu option. Flight Test 2000 automatically opens the "Ugly100" directory. Flight Test 2000 uses the same working directories as Aircraft Designer 2000. Select the "Ugly100.air" file.

When you launch Flight Test 2000, the General page is displayed. There are very few things to be said about the General page. The major remark refers to the name of the model. You must be cautious with the font style (capital letter or not) that you use to enter the model name in the input data field in the lower right corner of the General page. It must be the same as the actual font style that was used when the "*.MDL" file was declared for the first time. To know which style you must use, run the Windows™ explorer, look for the "Ugly100.MDL" file (it is in the "model" sub-directory of the "Ugly100" directory) and select it. Then, display its properties panel (right-click on the mouse to display the pop-up menu and select the properties option). The correct name and font style you should use is displayed in the "MS-DOS file name" data field.

Go back to the Flight Test 2000 window. Click on the Dynamics thumbnail. The Dynamics page is displayed. I suggest that you enter the following data :

The parameters related to the wing and the stabilizers can be directly "measured" in the "RiteWing" and "Ugly100" files with Aircraft Designer 2000 :

main span : 380 in chord : 65 in area : 175 sq.ft
horizontal area : 20 sq.ft span : 86 in location : 175 in efficiency : 0.9
vertical area : 17 sq.ft hauteur : 40 in location : 180 in efficiency : 0.75

Go to the Engines page. Once again, you can measure the actual position of the engines with Aircraft Designer 2000 :

right/left : 0.0 in
fore/aft : 96.0 in
up/down : 0.0 in

There is no reason to modify the default values proposed in the Fuel page. Go directly to the Gears page. You can find the position of the gear by looking into the "RiteWing" file with Aircraft Designer 2000. The right gear is 4.40 ft high and it is moved along a vector the coordinates of which are the following :

 6.300  0.250 -0.700

This would result in the following data in the Main gear sub-section :

right/left : 76 in
fore/aft : 3 in
up/down : -61 in

Actually, we shall have to cheat a little bit to get a better balance of the aircraft on the ground. I suggest that you enter the number 10 in the fore/aft input data field instead of the number 3. The main gear location (Central gear sub-section) can be calculated from the data available in the "Ugly100" file :

right/left : 0 in
fore/aft : -178 in
up/down : -36 in

The coordinates of the scratch points (potential points of contact of the structure with the ground in case of hard or even catastrophic landing) can be easily found using Aircraft Designer 2000 :

front scrapeside scraperear scrape
right/left : 0.0 in right/left : 180 in right/left : 0.0 in
fore/aft : 87 in fore/aft : 0.0 in fore/aft : -180 in
up/down : -20 in up/down : 0.0 in up/down : -10 in

The last page is the Miscellaneous one. The position of the pilot's head will be also determined by looking into the "Ugly100" file :

right/left : 0.0 in fore/aft : -62 in up/down : 20 in

The calculation of the angle made by the fuselage with the horizontal axis needs some maths but we do not need a lot of accuracy. We shall use a -5 deg angle value.

A "*.AIR" file includes many other parameters the meaning of which is unclear. These parameters are referred as hidden parameters in Flight Test 2000. To deal with these parameters, one solution could be to use another program (they are some of them available on the Internet) to adjust the hundreds of data which are included in a "*.AIR" file, then test the file, and then adjust the data again, and test again, and adjust again... Flight Test 2000 proposes you a different approach. You can simply copy these parameters from the "*.AIR" file of an existing model the characteristics of which is close to the model you are working on. To do this, activate the File|Load hidden parameters menu option. I let you choose the appropriate model in your own collection...

Once you are finished with the flight model, save the file (File|Save menu option) and test it. Enjoy your flights !

 


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- January, 2000 - Copyright Hervé Devred -