Modelling an aircraft - Tutorial in progress


#1

Some people have requested for a tutorial about modelling an aircraft.
These are the first paragraphs of that tutorial. I will keep adding stuff to this post as soon as possible. Take into account that the process here described is in fact my way of modelling an aircraft, with the acknowledgement of Blender I have and as EASL student I’m. To do this tutorial, a good Blender acknowledgement is desired.

1. THE AIRCRAFT.
[i]I can spend weeks surfing the web before deciding what is the aircraft I’m going to make. It mainly depends on the quality and quantity of the information available of that aircraft (blueprints with cross secctions and close-up photographs). Besides, the aircraft chosen sometimes had some protagonism in the history of my country or can be an aircraft never CG modelled before.

 The aircraft chosen this time is a Policarpov I-15 [b]Chato[/b]. This aircraft took part in the Spanish Civil War.

The blueprints of this aircraft can be found here:
http://www.airwar.ru/other/draw/i15.html

                              Information about the aircraft and some photographs:
                              [http://www.ctrl-c.liu.se/misc/ram/i-15.html](http://www.ctrl-c.liu.se/misc/ram/i-15.html)
                              [http://boozers.fortunecity.com/lolos/226/iindex.htm](http://boozers.fortunecity.com/lolos/226/iindex.htm)
                              [http://kits.kitreview.com/i15eviewse_1.htm](http://kits.kitreview.com/i15eviewse_1.htm)
                              [http://www.xs4all.nl/~fbonne/warbirds/ww2htmls/polii15.html](http://www.xs4all.nl/%7Efbonne/warbirds/ww2htmls/polii15.html)
                              [http://www.studenten.net/customasp/axl/plane.asp?cat_id=3&ple_id=563&page=0](http://www.studenten.net/customasp/axl/plane.asp?cat_id=3&ple_id=563&page=0)
                              [http://vvs.hobbyvista.com/Markings/I15/i15-part1.php](http://vvs.hobbyvista.com/Markings/I15/i15-part1.php)
                              [http://wp.scn.ru/en/ww15/f/359](http://wp.scn.ru/en/ww15/f/359)
                              [http://www.thehistorynet.com/ahi/blsovietfighter/index1.html](http://www.thehistorynet.com/ahi/blsovietfighter/index1.html)
                              [http://wio.ru/tacftr/polikarp.htm](http://wio.ru/tacftr/polikarp.htm)
                              [http://personal3.iddeo.es/opedrosa/chato.htm](http://personal3.iddeo.es/opedrosa/chato.htm)
                                        
                                        
                                        [/i][b]2. SETTING UP THE WORK.[/b][i]
                                     
                                     [/i]  [b]2.1[/b] Add the blueprint named [b]I1[/b] as background in a front view ([b]3 Key num[/b]). By now we don't need to change any of the background settings.
              
              [i]The blueprints are in PCX format. You can save them as JGP with your Image Manipulation Program.[/i]
              [b]                          
                       2.2[/b] We focus our attention to the cross sections at the botton of the blueprint. First, the most accurately possible, set an emply just in the center of the axis cross.
                                       
                                         [img]http://img160.echo.cx/img160/2663/ilus26dn.jpg[/img]
                                       
                                         [i]The cross sections are different in each side of the vertical axis. In fact, only half of the section is drawn in each case. The little segments in the left side sections indicate that between two of those segments, the fuselage is straight.

For example, in the E-E case, only part of the fuselage section is made of straight panel, whereas the other part is probably made of curved metal. We should compare that with a photograph of that part of the aircraft.

                                      [img]http://img91.echo.cx/img91/8918/ca006f0ob.jpg[/img]
                                      [/i]  
                                          [b]2.3[/b] You cursor must be set in the empty object's center. Once this is done, add a circle ([b]ADD>MESH>CIRCLE[/b]) and set its resolution to 24. Erase the right half of the vertices because we are going to work with the left half and the result will be mirrored later on the right.
                                      [img]http://img91.echo.cx/img91/9261/ilus2a3kn.jpg[/img]
                                      
                                       
                                          [b]2.4[/b] Move the vertices according to the blueprint. Vertices North, Sud and West should be moved with axis restriction.  
                                       
                                            [i]As a general rule, for modelling aircraft, in my opinion is always better to use axis restriction in editing whenever is possible. 
   
   In the submenu [b]Transform[/b] (both in [b]Object mode[/b] and [b]Edit mode[/b]) you will find transform options on axis.
   
   For example, in this case I duplicate the section, then I scale it on [b]X axis[/b] and finally I move the vertices to meet the blueprint; some of them moved on [b]X axis[/b], particulary those of the upper side of the section.

Another rules is better to carry on work from an existing information (meshes, vertices location) than to start from scratch.

                                        Make reference object (axis, alignments, etc) and keep them!
                                      
                                      [img]http://img62.echo.cx/img62/973/ilus2b7pp.jpg[/img]
                                      
                                        [/i]
                                  [b]  2.5[/b] Leave Edit Mode and duplicate the first section we've made. The duplicated one should be used to make the next section in the row. Once all the sections are finished, whe should end with something like this:
                                      [img]http://img214.echo.cx/img214/9189/ilus3a1lv.jpg[/img]
                                      
                             [i]Vertices should be aligned to form a nice grid. In the left picture, the vertices aren't aligned, while in the right, the vertices are all in one line.

[/i] [i]

                             [/i]
                             [b]2.6 [/b]Take into account that the reference objects that helped us to place vertices in the left side, should be mirrored in order to make the sections of the right one. 
      The sections [b]AA[/b] and [b]bb outer[/b] are perfect circunferences.
                        This is what I've got ([policarpov15-3.zip](http://www.cgtalk.com/attachment.php?attachmentid=74388)):

                        [img]http://img225.echo.cx/img225/1208/ilus5a3iw.jpg[/img]

#2

A tutorial of airplane modelling coming from the best airplane modeller I have yet seen using Blender. I’m waiting expecially for the upcoming “texturing the bits & pieces” =)


#3

thx, this looks like its going to be a great tut can you also include the html in the zip so its the complete tutorial + ref files?


#4

Alvaro u’re da man!
I think these tuts are gonna be one the best out there.
Looking forward to new updates
Great stuff


#5

Very nice indeed. Too bad that my current project doesn’t have reference, or I would have used your tut definately. :slight_smile:


#6

this looks like it will be a great tutorial however where you have the graphic with the two smiley faces and the line “There should be certain relationship between sections regarding vertices resolution and position for later face’s formation. I mean that::” it isn’t clear what you are attempting to convey.


#7

He’s trying to say that ideally, vertices should be aligned to form a nice grid. In the left picture, the vertices aren’t aligned vertically, while in the right, the vertices are all in one line.


#8

Sorry
Paintbox, I’ve pasted your explanation in the tutorial
better, clearer and nicer
:slight_smile:
thanks for your comments, IT REALLY HELPS!

a question:
What is better, carry on editting the first message or adding tutorial stuff in new missages?


#9

Keep on editing the 1st message. That way it is easier to see the development of your tutorial.
Alternatively post a link to your homepage (with tutorial, of course) in the 1st post and keep on going there. That would help others even more to keep an overview of your tutorial.
A pdf or printable html-page would also be nice - but maybe not before the tutorial is finished.


#10

Really nice Alvarus. Thanks for making this and for sharing.

You should link to this over at Elysiun as well. Others there, who don’t frequent this forum, would like to see it as well, I am sure.

BgDM


#11

3. LET’S START THE FUN!

3.1 We need to divide the 3D window up into two parts. Once this is done, choose one of them and, in a side-view, load the I2 blueprint as background. In this blueprint, locate a side view of the aircraft which has the section lines drawn:

                 3.2 This time we need to change the background settings. First, the scale for this blueprint should be [b]10[/b], because this side-view [b]draft[/b] has [b]1/2[/b] the scale of the cross sections we made before. 

Second, we have to offset the background. In fact, this aircraft side-view has an horizontal axis drawn, which is related to the axis of the cross sections we made before.

       I've set the background so that the A-A [b]section line[/b], the first one, meets the [b]empty[/b] vertical axis, and the horizontal axis of this side-view meets the empty's horizontal axis:
                 [img]http://img269.echo.cx/img269/6774/ilus71lt.jpg[/img]

3.3 Since only the upper endding of the section’s lines are drawn, would be nice to add a new object made of a bunch of lines which are placed just in the vertical of each one:

3.4 Finally, move each cross section we made before along the horizontal axis to meet its section line. This is what I’ve got (policarpov15-4a.zip):

                 [i]I've moved the cross sections along the horizontal axis holding [b]CTrol + Shift. [/b]I've done that because I wanted somehow to have precise distances between them. That could be good sometime in the future. For the same reason, It is always a good idea to place the reference empty (see [b]2.2[/b] paragraph) after a [b]CURSOR TO GRID[/b] action (and then slighly move the blueprint if necessary). Precise distances and locations can help in case we need to model with even more accuracy.
                [/i]

#12

I’m sorry for the people who is following this thread, but I have had to remake some things:

  • Paragraph 2.5, image changed.
  • Paragraph 2.6, image changed. Text changed. Attached file changed.
  • Paragraph 3.4, attached file changed.

Now the sections on the left side have their vertices more according to the sections on the right. It will result in a nicer mesh.


#13

Looking good mate. Maybe I’ll learn Blender one day :slight_smile:


#14

Looking good mate. Maybe I’ll learn Blender one day :slight_smile:

            Thanks Ronnie! 
            
            3.5 The next step is to mirror the sections we have on the left to the right. Use the [b]mirror local[/b] tool taking as mirror's axis the [b]empty[/b] object. Join all the sections together in an object. Duplicate this object and put the copy in a layer aside.
            [img]http://img101.echo.cx/img101/441/ilus101jg.jpg[/img]
            [i]I always back up my work in a different layer before taking the next step. Those back up's can be necessary in case we need some flashback but maybe It has more to do with the fact that older Blender releases had no undo. 
            Blender old school!:buttrock:
      [/i]
      [i]For the same reason, I keep saving as new files the work done. Take into account that, for modelling an aircraft, many times we will work with a modelling approach which may fail.
      [/i]       
            3.6 Finally, we can start to form faces from the vertices available in the sections. 
            
            Some recommendations:
  • Form your faces from a perpendicular view, for example, the front view (whenever is possible). In my opinion It helps to make a better mesh, to understand better the grid of edges we are working on.

             - Use the [b]show/hide vertices[/b] tool to work on the fuselage step by step:
             [img]http://img101.echo.cx/img101/8701/ilus124xo.jpg[/img]
             
             - Forget the wings and gears, we focus by now in the central tube ([[color=Plum]policarpov15-5a.zip](http://www.cgtalk.com/attachment.php?attachmentid=74464)):
             [img]http://img198.echo.cx/img198/6641/ilus132fz.jpg[/img]
    

About the attached files, if you have downloaded the blueprints and you correctly set their path in the background setting, they should load in the exact location I have them.
[/color]


#15

Hi again!

      [b]  4.1[/b] Modelling where the wings meet the fuselaje is the most difficult part in many aircrafts. The process I described above is my fourth attempt to model this part. Yes, it means that 3 attempts failed before. Sometimes, to success I need to rethink the strategy the next fresh morning after many failed attempts.
        
        [i]To get an opposite view of the default views (Top, Side, From) add [b]Shift+[/b][/i]

First we need a new arrangement of blueprints but it is interesting to keep the one we had before. So add a new scene. We have the scene’s browser in the upper center of the Blender GUI.

           In the right [b]3Dwindow[/b] I've arranged the top view of the aircraft aligned with a top-view of the model. In the left [b]3Dwindow[/b], I've arranged the side view that has the wing sectioned aligned with a side view of the model. With this [b]3Dwindow[/b]s sometimes is difficult to work because of their little size. Press [b]Ctrol + Up Arrow[/b] to maximize your area of work (and [b]Ctrol+ Down Arrow[/b] to get back).
           [[img]http://img241.imageshack.us/img241/2796/ilus152fx.th.jpg[/img]](http://img241.imageshack.us/my.php?image=ilus152fx.jpg)
           
      [b]  4.2[/b] Extrude a vertice from the wing part we already have and try to form the wing's cross section as it is drawn in the blueprint ([policarpov15-6a.zip](http://www.cgtalk.com/attachment.php?attachmentid=74558&stc=1)):
       [img]http://img279.imageshack.us/img279/9225/ilus169ud.jpg[/img]
       
       [b]4.3 [/b]In Edit Mode, I've hidden the most of the aircraft to focus in that area of work. I've made a face between the corner of the upper part of the cowling (still not modelled) and the edge of the wing. I've subdivided that face 3 times with [b]Beauty[/b] button activated ([b]Edit Buttons[/b]).
       [img]http://img289.imageshack.us/img289/726/ilus17a9xw.jpg[/img]
       
       [b]4.4 [/b]The next step is to select the center couple of vertices (previous pic) and adjust them to the blueprints in each 3Dwindow. To move the rest of faces smoothly acording to that couple, activate [b]Proportional Editing - Sphere Falloff[/b]. Remeber that you can adjust the area of that falloff with the mouse wheel (or Alt + +/- NumKey). Only those eight faces should be edited, the rest of the mesh should be kept as before ([policarpov15-7a.zip](http://www.cgtalk.com/attachment.php?attachmentid=74563&stc=1)):
       [img]http://img65.imageshack.us/img65/5871/ilus182ew.jpg[/img]

#16

4.5

        [b]Step 1[/b]. We can connect these faces with the existing vertices to model the front part. To model a nice mesh, first I've made some faces in the upper side. I've added some vertices by the way ([policarpov15-8a.zip](http://www.cgtalk.com/attachment.php?attachmentid=74845)).
    
    [i]Adding vertices to an existing edge is easy, just subdivide it. If you want to adjust the distance of that new vertice from a vertice at the end, just scale it with the cursor at that end (Cursor to selection, Pivot in Cursor mode)
         [/i]
        [b]Step 2[/b]. Keep in minf that face's [b]loop subdivision[/b] can help you to form intermediate faces in case you have extra vertices to connect. I've used the [b]Loop Subdivide[/b] tool to split those faces into three parts, because I wanted to give continuity to the vertices of the wing's cross section. I've added a vertice in the top edge of the fuselage too.
        
        [b]Step 3[/b]. Finally I got the job done. ([policarpov15-9a.zip](http://www.cgtalk.com/attachment.php?attachmentid=74846))
        [[img]http://img84.imageshack.us/img84/7130/ilus2a9mp.th.jpg[/img]](http://img84.imageshack.us/my.php?image=ilus2a9mp.jpg)
       
     [b]  4.6[/b] More or less, using the same technique, I've modelled the down side of this area. ([policarpov15-10a.zip](http://www.cgtalk.com/attachment.php?attachmentid=74847))
       [img]http://img159.imageshack.us/img159/2738/ilus33fx.jpg[/img]

#17

Not much to comment other than keep it up!


#18

Thanks Joat and thanks to the people who are downloading the example files.

       [b]4.7[/b] We are going to model the rear part more or less using the same system. I mean: First modelling an edge we can adjust according to the blueprints, this time the end part of the trailing edge. Then, with the vertices available, we will make the faces.

I’ve made this edge by extruding the vertices of the rear of the wing’s cross section towards the fuselage. No subdivision this time, I kept extruding in the front view acording to the blueprint and, at the same time, adjusting it in the others views to make a nice curve (policarpov15-13a.zip):

      [i]When you create new vertices, take into acount the existing vertices first.
      [/i][img]http://img197.imageshack.us/img197/7691/ilus50mw.jpg[/img]

Clic in the image below for a Blender’s screenshot:


4.8
Then make faces, like we did in the front part (policarpov15-14a.zip).

4.9 Then, get the job done by making faces between the front and the rear part. With that, the upper wing connection with the fuselaje is finished (policarpov15-15a.zip).

Remember that face’s loop subdivision can help you to form intermediate faces in case you have extra vertices to connect. By the way I sometimes delete or add an extra vertice by subdivision if required.

      [img]http://img94.imageshack.us/img94/2143/ilus72cy.jpg[/img]

#19

5.0 The next step will be modelling the lower wing’s connection with the fuselaje. This time we will use a new trick.

I would like you to see this tutorial like a bunch of tips and tricks ready to be used in any moment rather than a fixed way of modelling an aircraft. I discovered this trick wondering if there was any way of calculating a given point inside of a face with Blender tools. In fact, there is.

           In many aircrafts, there is an intermediate curved surface that smoothly connects the fuselaje with the wings (pink). 

What I’m trying to make is modelling just the intersection between that curved surface and the fuselaje as is drawn in the blueprint. This intersections should be integrated into the fuselaje itself (green).

The only way to define this intersections is by points, and we should be able to calculate these points up into the faces that form the fuselaje (policarpov15-17a1.zip):

           [img]http://img252.imageshack.us/img252/1559/ilus98ra.jpg[/img]

How?
It’s easy. I will explain it with images, but the concept behind is the Descriptive Geometry problem “A point that lies in a plane is the point that lies along a line of that plane”
Suppose I want a point that lies in a face and just on the red spot of the blueprint I have as background:
(Clic in the image below)

    With this process I've made all the vertices needed for that intersection. 
   Finally I've joined all the vertices together with edges and I've erased the unnecessary ones. 
   I've made vertices of the belly according to the view from below in blueprint [b]I1[/b].
   Notice that the lower wing's cross section is already modelled.
   [img]http://img296.imageshack.us/img296/738/ilus111xw.jpg[/img]

#20

Keep up the tut, Alvarus. Since I’m not doing any modelling at the moment it’s a bit too detailed to follow just for fun, but I’m sure it will be a lot of help when the time comes.
It is important to see this finished, since it is already a good tutorial. It seems to cast a lot of light in the details of making a complicated mesh out of blueprints. And making a complicated mesh in a rational and smart way.
Make no mistake about it, if comments and encouragement seems to fade it’s not because of the quality of your work or this tutorial. People just seem comment a lot on the start and lay back to watch when things start to take shape.
It’s like that with WIP:s also.