Low Poly Aircraft Modelling Tutorial

[Mathias]

In the following I'm reposting Gerard's tutorial here that has been available at Netwings. Netwings apparently is no longer and as most of you know Gerard has passed away early this year. so before it all gets lost.....

Edit: the images have disappeared, so an old copy of the tutorial has been uploaded to the Library in PDF format, complete with screenshots.

Gerard's Low-Poly Modelling Tutorial

(up when the library has looked it over)
​

 

[Mathias]

INTRODUCTION

Johann Steve recently asked me to help out with building a Junkers EF128. I had a quick look and realized that I could "kill two flies with one blow" as I had promised to write an aircraft modelling tutorial earlier this year. The Ju128 is a suitable subject for a tutorial; a quick build but with a few complex curves and interesting detail. I will try to post something every day, build the aircraft as I go along. I use 3ds max 7 but I'll suggest workarounds for tools gmax doesn't have.

This tutorial is meant for the intermediate (g)max user who already has a basic knowledge of the software's user interface. Don't hesitate to ask questions though, quite a few helpful people hang out here.

REFERENCE MATERIAL

Well, there's one reason why the Ju128 is a very bad choice: lack of references. However, it's a typical Luft'46 plane, one that never left the drawing board, which means we will have quite a bit of, er, artistic license. A mock up and windtunnel models were made though, they can be seen here:

http://www.luft46.com/junkers/juef128.html

Nevertheless, would you normally base a project that will take many hundreds of hours on one crappy 3-view culled from the net? No way, you would cross reference several sets of high quality drawings (which will all contradict each other) and gaze at hundreds of photo's!

PREPARATIONS

One question that pops up from time to time (on sim modelling forums as well as the Discreet/Autodesk web board) is: "What's with the perspective viewport, small parts disappear when I zoom in?!" The reason is simple: the (g)max viewport "camera" just cannot cope with the very large and the very small at the same time, so, it's important you choose your system unit wisely, not only to get rid of viewport clipping, but also to get interactive tools like chamfer to work properly. Check Family Fare Ad and Fareway Ad. I usually set 1 system unit = 1 centimeter for aircraft work, and 1 millimeter for small intricate stuff like cockpit instruments. Now, I know the MS SDK's want you to use 1 meter scenes but there's an easy solution to that: set up a 1 meter scene purely for export and merge your 1 centimeter work into it, easy as pie.

As to setting up a backdrop studio... it all depends on personal preferences. Personally, I don't like to fiddle with mapped boxes; too much work and not flexible enough. Neither do I like to straighten drawings out (scale, rotate) in Photoshop, as resampling degrades image quality. I just copy and paste the left, top, front, etc. views onto square 512, 1024 or 2048 pixel canvasses - depending on drawing size. Then I create a new layer, fill it with pure blue and set opacity to 30%.

In 3ds max I activate the top viewport and draw a box by typing in the aircraft dimensions in the Box primitive Keyboard Entry rollout and hit Create. Next I check See-Through in Display Properties (Display tab of the Command panel or right-click > Properties). Once I have the dimensions box I can draw and map square backdrop Plane primitives in the appropriate viewports and move/scale/rotate them until the drawings fit the box. Lastly, I uncheck Show Frozen in Gray, in Display Properties and freeze the backdrop planes.

 

[Mathias]

THE FUSELAGE

Looking at the left view we can make out four logical fuselage sections: a nose "cone", cockpit, mid and aft section. At each section the fuselage changes shape. In the early phase it's important not to add / think more sections than needed.

Some Spline Kung Fu

I think we can assume section D to be circular, which makes it a good starting point. Create a Circle Spline in the Back viewport, use Keyboard Entry; it will perfectly center the circle. Use the Left view to move the circle into position. In the Modify panel you can adjust the radius. There's also an Interpolation rollout, open it and drag the Steps spinner down to 0: the circle changes into a rectangle. This is important: the software uses intermediate steps to define curvature. The more steps, the better the spline approximates a true curve. Set Steps back at 6.

Next, apply an Extrude modifier to Circle01, set Amount to 70 cm or so and uncheck Cap Start and End. Now, the resulting mesh is rather dense for a low-poly model but the object stack allows us to go back to the circle spline and set Steps to 5, this gives us a 24-sided cylinder:

Section B is next as it is, at least for a large part, visible in the front view drawing. In the Left viewport, select and move Circle01 to the left (along the view x-axis) while you hold down the SHIFT key; tick Copy in the Clone Options window and click OK. In the Circle02 object stack window, select the Extrude modifier and delete it. According to the Luft'46 info, fuselage width is 1.27 m, so we'll change the radius to 63.5 cm. Apply an Edit Spline modifier, select the bottom vertex and move it down until it reaches the bottom line of the drawing. As for the top vertex, we're not going to move it up to the top of the canopy but to the top of the "true" fuselage:

With the Back viewport active, go to Segment sub-object level, select the left half of the spline and delete it. Go to vertex sub-object level, select the bottom vertex and drag its tangent handle (little green square) to the right until the spline nicely fits the fuselage "belly":

Next, select the mid vertex, drag its bottom handle a bit to the right and the vertex itself a bit to the left. Do not move the mid vertex up or down (I'll explain later). Lastly, adjust the top vertex handle until you end up with something like this:

Nice, but not perfect. We need to be able to independently move the mid vertex' tangent handles. Select the mid vertex, right-click it and choose Bezier Corner in the quad menu. Now you can move one handle independent of the other:

Circles have Bezier type vertices by default. There are four different types; in vertex sub object level, right-click any vertex and you can set vertex type to:

Smooth: Nonadjustable vertices that create smooth continuous curves. The curvature at a smooth vertex is determined by the spacing of adjacent vertices.

Corner: Nonadjustable vertices that create sharp corners.

Bezier: Adjustable vertex with locked continuous tangent handles that create a smooth curve. The curvature at the vertex is set by the direction and magnitude of the tangent handles.

Bezier Corner: Adjustable vertex with discontinuous tangent handles that create a sharp corner. The curvature of the segment as it leaves the corner is set by the direction and magnitude of the tangent handles.

Right, let's see how this thing shades. I've Applied an Extrude, Symmetry and Smooth modifier, and assigned a material with a fairly high specular strength:

Not bad but edge/vertex distribution could be better; vertices are too far apart at the bottom and too close together at the sides... Next time we will do something about it. We will also start working with the Editable Poly, oh, and finally build something that looks like a fuselage.

The Editable Spline is your friend though: you can draw fuselage cross sections (as well as wing airfoils), extrude them, convert to Editable Poly and work from there. I must admit however that I almost never use Bezier vertices; I just put a (corner type) vertex where I want an edge and keep Interpolation at 0. More on that later.

TBC

gh

 

[Mathias]

Here's the basic fuselage mesh. Edges flow nicely, even around the cockpit cut-out and there's only four triangles, the rest is all quads. The nose shades beautifully thanks to [gasp] Subdivision Surface... Normally I wouldn't use subdivision because of the high poly counts involved but for a nose like the Junkers' it's perfect, and economical too: 112 faces for the nose tip, out of 576 total:

It went as follows. I copied and modified Circle02 to get section C. I converted Circle01 (section D) to Editable Poly, selected the left edges, clicked the Align button (toolbar) and picked section C. I left everything at default settings and hit OK (Fig.1). Next I deleted the right half of Circle01 and changed its name into "fuselage". Using section C as a template I moved the fuselage vertices into position. For the top half I used 3D vertex Snap, the bottom half I moved by hand because I wanted better vertex distribution there (Fig.2):

I selected all polygons, clicked the Slice Plane button and moved the plane to where I wanted a new edge loop, and clicked Slice:

Now comes the really important part: the new edges and vertices need to be scaled so select the top 7 vertices in the Left viewport (I like to work with vertices but you can use edges too of course), click Non-uniform Scale, select Parent as reference coordinate system and choose Use Transform Coordinate Center:

This way, and only this way, we won't mess up the flow of edges while scaling. Now, one could yank the vertices or the Transform Gizmo but I prefer to drag / click a spinner in the Transform Type-In (hit F12), in this case the Offset: Parent Y spinner. It'll give you better / more precise control. Scale the vertices. Do the same with the bottom vertices. Then, in the Top viewport, select all thirteen new vertices and Non-uniform Scale along the Parent x-axis. I can't stress this enough: be aware of what reference coordinate system and center you use when you scale or rotate. The settings we used kept the edges in the middle nice and straight:

As you can see I added one more edge loop to get somewhat of a fuselage curve.

Right, the nose is next, stay tuned.

gh

 

[Mathias]

THE NOSE

In the Left viewport, select the edge loop at C, hold down SHIFT and move (View x-axis) the edges towards B. As you can see SHIFT+Move extrudes edges, this is very handy, I use it all the time. The new fuselage segment will not be smooth, to correct this, go to Polygon sub object level, select all polygons and click the blank Smoothing Group button. Now the old and new polygons share the same Smoothing Group:

In the picture you can see I've scaled the vertices at B along the Parent y-axis to make them fit the drawing. Like I did with C, I scaled per top and bottom half and used Use Transform Coordinate Center.

Right, so what do we do now; extrude and scale a dozen times to get the cockpit section and the nose? No, it'll produce a mesh that gets very dense near the tip of the nose which can easily foul up shading. It's also quite hard to do well so let's use a more elegant solution.

In the Back viewport, create a box roughly the size of the nose, right-click it and convert to Editable Poly. If you need to center the box: with the Back viewport active, click the Move tool and type "0" in the X type-in field at the bottom of the UI. In Display Properties, check See-Through:

With the box selected, check Use NURMS Subdivision in the Subdivision Surface rollout; our box changes into a squashed ball (Fig. 1). What happens here is that new vertices are created at the center of each original polygon and edge. The new vertices are then connected with new edges. Subsequently, a new position is calculated for all vertices. For more information see: http://symbolcraft.com/graphics/subdivision/ As I understand it, Max's NURMS (Non Uniform Rational MeshSmooth) is based on the Catmull-Clark subdivision algorithm. There's more to NURMS though. For instance, in Max the original vertices and edges have Weight, with which you can influence the way things are averaged / smoothed.

Now, since we don't want a ball we'll delete the back polygon. You'll notice that as soon as you go to polygon sub object level, the original mesh appears (Fig. 2). It acts like a control "cage"; moving its edges and vertices is a bit like moving the tangent handles on a spline. You will also observe that the subdivided mesh can't be edited directly. Next, select the top-left vertices in the Left viewport and move them down until the mesh more or less matches the drawing. Do the same with the bottom-left vertices, this time moving them up (Fig. 3) In the Top viewport, select the top four vertices and Non-Uniform Scale them along the View x-axis (Fig. 4):

It looks promising but we need higher resolution, in fact, we need 24 edges at A. In the Subdivision Surface rollout, set Iterations to 2. This gives 16 sides. Merely moving vertices can give excellent results, too bad we need 24 edges:

In the Left viewport, select all four vertical edges and click Connect in the Edit Edges rollout, this creates 3 new edges at the center. gmax users can use the Slice Plane (Fig. 5). Now there's 24 edges at A but the thing is rather boxy looking. To fix this we'll have to move vertices again (Fig. 6).

Well, there you have it. The cockpit section is next.

gh

 

[Mathias]

THE COCKPIT SECTION

In the Left viewport, select and SHIFT+Move the edge loop at B to create a new segment, then, snap the vertices to the nose using, well, 3D Vertex Snap. Now we're able to judge edge flow, see if the nose needs one last tweak before we attach it to the fuselage and indeed, it seems the edges need to go up a bit more... or maybe not; better build both and let the best mesh win:

Looking at where the canopy is going to be, one vertex is at the right location - that is, as seen from the left, in Top view it's a different story (Fig. 1). I'll have to move it and the one below but before I do so, I need to add another edge loop because I don't want the fuselage to start widening at C. Also, there need to be edges at the end of the canopy extension / air intake anyway. I must add that I saved a copy of the fuselage for lower LOD work and refined the belly of this one by adding some edges; otherwise the landing gear doors will look a bit too low-poly (Fig. 2). After that I can move the vertices in the Top and Back viewport (x-axis)(Fig. 3).

The obvious location for the next edge loop is right at the canopy cross framing, where it's at its widest. I scaled the new vertices and moved them (all at once) up a bit (Fig. 4). As you can see, I'm in luck as there's an edge right where it should be, or almost; it could use a bit of tweaking I suppose (Fig. 5). The last edge loop will be at the lowest point of the canopy (Fig. 6).

Next, I need to make another cut for the canopy. QuickSlice in concert with 3D Vertex Snap is ideal for this sort of thing (Fig. 7). Now I can simply select the unneeded poly's and delete them (Fig. 8).

Lastly, we'll scale those three edges at an angle with the help of a Point helper object. Activate 3D Vertex Snap, and place the Point helper at the bottom vertex. I used the Left view. Then, rotate until it's at the right angle (Fig. 9). To use the Point's local coordinate system, choose Pick from the coordinate system flyout and select Point01. Make sure Use Transform Center is active when you scale (Fig. 10).

In the Top viewport I created an edge where the canopy extension is going to be and detached (might need them later on) the polygons (Fig. 11). To finish up I removed two nose edge loops and replaced them with a single one (Fig. 12).

The thing with the "lucky" edges gives reason for pause; it might be a good idea to carefully plan your mesh; to think through the repercussions of placing vertices on the first cross section spline... Admittedly, I often think about it a little and then just start and hope for the best... promising myself to rebuild when things get ugly.

gh

 

[Mathias]

The Canopy

While we're on the subject of coordinate systems and transform centers, here's a bit of mandatory reading: http://www.cgarchitect.com/upclose/article5_TB.asp

Select the three edges at the front and SHIFT+Move them to the right (Fig. 13). With the Back viewport active, hit View Align in the Edit Geometry rollout, this will perfectly align the edges (Fig. 14). Next, activate 2.5D Vertex Snap and in the Left view snap the lowest vertex of the extrusion to the upper fuselage vertex at B (Fig. 15). 2.5D snap takes into consideration only the Left view x and y-axis, not the z-axis (facing towards you) which is exactly what we needed. If I had used 3D snap, Fig. 16 would have happened:

Target Weld the lowest vertex of the extrusion to the upper fuselage vertex at B. I scaled the 3 vertices up a bit to give the back of the canopy the right height. Again, vertex snap comes in handy for this: in the Left view select the 4 upper vertices at B (Fig. 17). Activate 2.5D Vertex Snap, Non-Uniform Scale, Y-axis constraint and Use Transform Coordinate Center (Fig. 18). Next, click (snap to) the lowest vertex and drag upward (Fig. 19). Scale or Rotate transforms with Snap in conjunction with Use Transform Coordinate Center is a very cool but little known feature, and even gmax has it In other words, with Snap you can use any mesh sub-object as a rotation or scale center.

Add a vertex to the lower edge of the canopy; Max users use Insert Vertex (Edit Edges rollout), gmax users use Divide (Edit Geometry rollout), then, Target Weld it to the fuselage:

I created 3 new edges with the QuickSlice tool (Fig. 20). Last time I created a Point helper object / coordinate system for scaling the new vertices but this time we'll use a Tape object; more convenient and accurate since you can use 2.5D snap for both start and endpoint. BTW, the Tape helper will not just be for scaling (Fig. 21-22).

Next, I created the canopy extension. I only used previously discussed techniques; you should be able to do it on your own:

It's probably a good idea to save another copy of the fuselage at this point; we're going to refine the canopy but lower LOD's won't need that.

Okay, let's detach the canopy and name it 'canopy_frame'. It will inherit the pivot from the fuselage which can get confusing so in the Hierarchy panel hit Affect Pivot Only, and then Center to Object. Lastly, delete the right half.

In the Back view, move 2 vertices of the "cross bar" to get a somewhat decent curve. Don't forget to use the Taper01 coordinate system, which means you'll move along its ZX-axis (Fig. 23). Next, create extra edges (Fig. 24); max users use the edge Connect tool, gmaxers... well, they'd better download and install Meshtools 2.5 right away as it has something similar. You can download it here: http://www.scriptspot.com/start.htm And then there's some more moving (Fig. 25).

I added and scaled edges to get a nice curve (Fig. 26). Next, use a Symmetry modifier or Clone and Mirror. Create a copy of canopy_frame and name it canopy_glass. In the Left viewport, create a box and align it to a Tape object that runs along the bottom edge of the canopy (Fig. 27). Also, make sure the box is wider than the canopy. Next, SHIFT+Move the box to the left along its local z-axis to make a copy. Convert one box to Editable Poly and attach the other to it. Move vertices to make it match the drawing. Copy the box. We will subtract this box from canopy_frame and do an intersection with canopy_glass (Fig. 28).

 

[Mathias]

Booleans

The thing with booleans is they work best with enclosed objects, so first create 2 polygons at the bottom (click corner points in a counter clockwise fashion, otherwise the polygon will face the wrong way)(Fig. 29) then go to Border sub-object level, select the borders around the remaining holes and hit Cap in the Edit Borders rollout (Fig. 30). Now canopy_frame is (hopefully) ready for a boolean (Fig.31).

With canopy_frame selected, go to the Create panel > Compound Objects > Boolean, click Pick Operand B and select the box. The result looks promising although there seem to be some irregularities (Fig. 32). Convert to Editable Poly and go to polygon sub-object level. You'll see that all polygons created by operand B are already selected, which is nice; now we only have to hit the delete button or key. Go to vertex sub-object level. In this case the boolean worked perfectly but more often than not you'd remove / target weld stray vertices (Fig. 33-34).

To prepare canopy_glass for a boolean I applied a Shell modifier with Outer Amount: 0 and Inner Amount: 0.12 I also checked Override Inner Mat ID and set Mat ID to 4. Next, I converted to Epoly (Editable Poly), used Mat ID 4 to select the inner polygons, did a Select Invert and deleted the selection. Needless to say, the remaining polygons faced the wrong way so I flipped them. Lastly, I again applied a Shell modifier with Outer Amount: 0 and Inner Amount: 0.15. 0.15 is a bit arbitrary; it's just to give canopy_glass some thickness; make it an enclosed object.

You're probably asking yourself what the fuzz is about, well, I didn't want the glass to be at the same level as the canopy frame. Here's a close-up (the glass is light gray):

So, I did a boolean intersection with the box, selected the outer poly's and deleted the rest. Then I applied a Shell modifier to give the glass some thickness again.

Experienced max users will wonder why I didn't use a Push modifier the first time, to push the glass inward... well, I've found the Shell modifier to be more reliable

gmax doesn't have a Shell modifier; gmax users will have to extrude polygons inward either through polygon sub-object level or Face Extrude modifier.

Back in a mo

gh

 

[Mathias]

The extension I built in a similar fashion. This time Operand B was slightly more complicated. Note: bottom and side poly's already deleted for clarity (Fig. 35). When they are close together I often move vertices-to-be-welded away from their targets before I attach an object; it'll make target welding easier (Fig. 36).

Lastly, I built a rather basic cockpit interior; I used a Shell modifier to extrude the entire cockpit section 4 cm inward and then sliced, extruded, view-aligned and created polygons to make the floor, front / back walls and consoles.

Right, the most challenging part of the Ju 128, the air intakes, is next. Watch this space

gh

 

[Mathias]

Gunports

What can I say? Adding detail locally to a low-poly mesh can ruin your day; all those new triangles bring their own normals which often affect shading in a bad way. This is especially true for gunports, which are basically cylinders that intersect a surface... a curved surface at that. Curved surfaces are often made of non-planar polygons, as is the case with our Junkers' nose.

To illustrate what's going on I've subtracted a cylinder from a planar polygon and a non-planar (slightly twisted) polygon:

The planar (flat) polygon shades perfectly, the non-planar one, at the bottom, does not. When we look at the face normals in front view we can see why:

They go in all directions, and the result is that under certain conditions, the (viewport or game) renderer will compute a gradient between non-parallel normals; lighter and darker areas will disrupt shading.

Unfortunately, there's no definite solution; in programs like 3ds max you can edit normals but no MS sim supports this. You can however mitigate the problem somewhat by adding edges; to make sure there are no elongated triangles. First, I detached the nose from the fuselage, selected the border and hit the Cap button to make it a "solid" object. Again, this is to prepare the nose for a boolean (Fig. 1). Next, in the Back viewport I created a cylinder with the right width and moved it into position. I watched the Left viewport as I dragged the Sides spinner and settled for 13 Sides; not too many (as many new faces will only make a bad situation worse) but enough to make a decent curve at the intersection (Fig. 2). After a boolean subtraction the nose looks like Fig. 3, not a pretty sight:

Convert to Editable Poly, go to Polygon sub-object level and click the Edit Triangulation button. As you can see in Fig. 4, there are elongated polygons aplenty. Fig. 5 shows how I've edited (turned) some edges. Shading is a little bit better, but not much:

Before we go any further, I'd like to add that I wanted the gunports to have rounded edges, just like the real thing. It's detail like this that separates the interesting models from the rest. Now, a series of chamfers is out of the question as that would produce vertices less than 1mm apart and we can't have that in flightsim models. The answer is a "solid chamfer" or "bevel" as the author of the following tutorial calls it:

http://www.3dluvr.com/content/article/149/1

It saves me quite a bit of typing so please do read it. Solid chamfering is of huge importance to "next generation" flightsim models. When we get to the air intakes and wings you'll see why. Here's what I ended up with:

Not bad, but how does it look in-game? Well, here's two stages of editing with the one on the right being final (for now). It's easy to get carried away with this; before you know you've added dozens of edges without ever reaching perfection. Oh well, the texture will do the rest - besides, most real aircraft don't "shade" too well either, up close There's still room for improvement of course.

This wireframe pic. shows what I did. I detached the interior polygons (Fig. 6), created a cylinder with a slightly larger radius and subtracted it from (a copy of) the nose (Fig. 7). Then I reattached the interior and created a "loop" of polygons by hand (I like doing that)(Fig. 8) and lastly, I cut some new edges (Fig. 9) with the Cut tool. Fig. 10 shows the new hidden edge situation; less elongated triangles.

gh

 

[Mathias]

Quote:
Originally Posted by pippz
btw .
gerard i guess u r really busy with that fokker at the moment ..but .. may u find a second to explain us in detail (oh well, a pair of pics could make me happy) that loftin tecnique ?=) (lofts are my real nightmare)

thx



Right, let's talk lofts then. The (Ed.: Gerard's old wingtip tutorial) tutorial is quite old so here's a quick update.

BTW Gib, check out this site: http://www.aae.uiuc.edu/m-selig/ads/aircraft.html it tells us the P38 had a NACA 23016 airfoil at the root and 4412 at the tip. Go here to generate a piccie: http://www.pagendarm.de/trapp/programming/java/profiles/NACA4.html you need to have Java runtime installed.

So, I did a quick version of a P38 wing

 

[Mathias]

Next, I drew an outline of the tip in the top viewport. Set interpolation to 0 and make sure all vertices are of the Corner type.


View attachment 75144


Then, in the right viewport, I "traced" the leading 6 edges of the wing with a line using 2.5D vertex snap. Next I moved the shape's pivot to the leading vertex, also with vertex snap.

 

[Mathias]

According to the (dubious) drawing I used, the bottom of the tip has a distinct angle so I rotated the tip path a bit and moved it in place.

Time to Loft. Select the tip line and hit the Loft button. Click Get Shape and select the leading edge line. In the modify panel, set Path and Shape Steps to 0. You might also want to check Flip Normals. If all goes well it will look like this

 

[Mathias]

In the Deformations rollout, click Scale, a window will pop up. Move the right point down to about 6-7%

Now, the thing is, some game engines weld "colocated" vertices on the fly so it's a good idea to check your sim's requirements/specs. For FS it's < 1mm. We can mimic this in max, just put a Vertex Weld modifier on top of your stack, set it to 1mm and make sure the Show end result toggle is on. Now you can interactively see how far you can scale down the Loft end before vertices get welded.

That's it for now, I'm sure you can fill in the gaps

If you're serious about it you'll prolly want to use slightly different shapes half way and at the end, that sort of thing. There's lots of control, lofts are cool.

 

[Mathias]

That's it folks, enjoy!

 

[hairyspin]

Yippee!

Thank you very much, Mathias!

The pictures had been lost from Netwings for at least 6 months (broken links since Gerard's site expired) and I for one regretted not saving the entire post beforehand.
I'll not miss this chance!

You hadn't saved bzhyoyo's SE5a thread, by any chance? A lot of good stuff in there...

 

[Mathias]

You hadn't saved bzhyoyo's SE5a thread, by any chance? A lot of good stuff in there...

Unfortunately not, though I think I should have the propeller writeup somewhere.

 

[Milton Shupe]

Thank you Mathias. I have reviewed this several times since it was originally posted and am happy that you had preserved it.

 

[FelixFFDS]

Thanks... I've saved and zipped this thread complete with images, etc.

 

[Mathias]

Dang, would a moderator please be so kind and edit post #12.
The first image should be named "wt1.jpg", not wt2.
Sorry for that.

http://www.classics-hangar.de/privat/Gerard_tuto/wt1.jpg