STEP 2

STEP 2

For this STEP 2, I will show you ONE way to start this kind of part. Of course there are a plenty of way (probably one by each modeller!).
I used for this exemple some Nurbs Curve (compare to the Bézier one).
The most of the Class A modellers would like to use the Bézier workflow and/or mono span...
Here I cannot explain all details regarding Bézier vs Nurbs, but you need to keep in mind one thing: CONTROL all the time each parameter curves and or surfaces built by your software, this is can called the "explicit modelling".
Never belive what your software done! In general do not belive everyone (same for me)...

I will show you how to rebuild some curves according to the scan clean in the the STEP1.

(for information: As I said before, this is a hand made model, also when I will rebuild the main curves I cannot follow exactly the shape build by hand... If you need to reproduce the exact shape you need more time but the workflow does not change too much).

The most difficult for me is to build a curve with the minimum control point according to the shape we would like to copy...

Same there are a plenty of curves, spline, arcs etc... show the one you like and the one you can control as you want:

Here I copy the shape with one curve and after I copy > move > scale > modify the control points for doing the second curve under. Now I have two nurbs curves with the same parameter, degre 4 / 3 span (nurbs)

Here I use some surfaces to cut the scan and find other sections... After that I need to rebuild the sections by new curve (controled)... Many soft have some more or less automatic way to define all of this cruves. Did as you want BUT CONTROL your work all the time. (sorry I said again and again "Controle" but for me Class A is only control data workflow...).

Here you can see some "green" surfaces who can help you to define some G1 according to the symetric part and also some direction if you need it like X for the biggest section (right on the picture).

Becarful, I build only one nurbs surface with 4 sections and two paths... Many modeller tell you this surface is not Class A (probably) but you need to work according to your customer and area standard.

Usually, sometimes I start with a nurbs workflow to define the most of the shape and step by step I come back to the besier workflow if I need to add more details and or more quality...

See you for the STEP 3 ;-)