cockpit fairing (?) and loft tut

[bzhyoyo]

Hi all,

a small tut about a possible use for lofts. Any comments on how to improve the workflow are welcome.

First, I'm using Max but most of the steps should work too in Gmax.

Let's start in top view of the fuselage. (image 1)

1) Draw a spline : choose line. (image2)

The vertex type should be corne (or maybe not, but more on that later).
Put the vertices exactly where the vertices end the sections of the fuselage. (image 3)

Left click to create a vertex. To close the spline, right click. Let's name this spline path for future reference. Move it to the right so that it will not be hidden by the fuselage. You can see we have something following the shape of the cockpit.(image 4)


2) Go to right view (or left, depends on the side you started modeling)
the path doesn't really fit the cockpit shape so adjust the spline vertices like in step 1. (image 5)

Don't be afraid to zoom in and be precise (without being 0.0000001 precise but still...)
Why : if you want the coaming created to follow as closely as possible the shape of the fuselage, you'd better be careful at this stage.

OK, the path is ready for lofting. (image 6)

[bzhyoyo]

3) Now, the coaming being essentially a rounded shape, draw a circle in the left viewport (This is VERY important) (image 7)


Once the radius of this circle is adjusted, go to standard primitives, compound objects and select "loft".
As your circle is selected, under the creation method heading, click on "get path". Notice how the pointer's shape change.(image 8 )


Click on the path (the spline created in 1).
If that doesn't work this way, choose the other way round : select the path and in the loft tab, select the "get shape" creation method.

Sometimes, you also don't get the shape you want because the loft uses the first vertex of the spline to create the object. Here, we want to start the loft at the front of the cockpit, so make the spline vertex at the front of of the path the first one. For this, right click on it and choose "make first" on the menu.

5) the loft has been created. (image 9) NB : I would save this loft for lower lods.


Hum, looks a bit low poly... select the path again.
Now, right click on the vertexes and choose "smooth" and look at the results. (image 10)


You've just discovered one of the great advantages of lofts : the changes you bring to the path spline are immediately visible on the object.

[bzhyoyo]

6) Still not exactly what I want at the corners, it should be more rounded.
Select the vertices in the right view and click "fillet". If the option is not available in Gmax, make the vertex "bezier" and tweak the curve with the handles that appear. You can see the result on the left corner, I haven't done the right one yet.(image 11)


7) That looks good but it uses a lot of polys.(image 12)


Scroll a bit down and unroll the "skin parameters" heading.
Uncheck "cap start" and "cap end" as it will be useful when you will mirror and create the second half.
Have a look at the options "shape steps" and "path steps". Default is set to 5 in Max.
Choose 2 for both "path steps", and "shape steps". You can see it optimizes the shape and the path.
Quite handy, eh? If you're a bit tight in your polycount, choose 1 for either of these settings.

8 ) You can see that the edges in the box are not really needed. (image 13)


So put an "edit poly" modifier in the stack and target weld these vertices.

NB : I would not convert the loft to an editable mesh or to an editable poly or I would keep a cloned copy before doing so. The reason is that with two clicks, you can afterwards create more low-poly meshes of your loft with the options described in 6. Very useful for lower lods !

9) Some fine-tuning now : in general, cockpit coamings haven't got perfectly round sections. So select the circle created 3, put an "edit spline" modifier in the stack and tweak the vertices.(If you don't know splines, grab the handles in move mode). (image 14)


Another cool feature of lofts.

[bzhyoyo]

10) Even more fine tuning : I target-welded and welded some vertices, especially at the back, to optimize the use of polys. Be sure of what you want to modify because if you forget something after the next step and you collapse the stack, it will be twice the work!

11) After having deleted the polys that close the shape, you can now mirror it and weld the vertices at the intersection. I use a "symmetry" modifier in Max. Final polycount : 1056. However, I may delete some polys that will be unseen afterwards. (image 15)


wireframe to illustrate what I said in 10 (image 16)


NB : I put a smooth modifier to... smooth things out, seems to me it's slightly more efficient that way than selecting the polys and clicking on "autosmooth"
probably just an illusion...

That's it.
I assumed most of the steps were clear for non starters like us at modeling. I hope I didn't explain the obvious too much. But if you have any questions, do ask

[Mathias]

Lionel, in the first steps, why don't you just select the edges that make up the fairing and select "create shape from edges"?
Saves you a lot of work and fits 100%

[bzhyoyo]

Yep, Polovski already told me so but I was too lazy to re-write the tut. Thanks for pointing it out though, I should have mentioned it