In this position I can work with the wing mesh, moving vertices along the global coordinate axes (i.e. I can set it “in the Northrop way” by setting the object incidence angle to 2.5⁰. To provide as many “technological bases” for my model as possible, the X axis of the wing object is parallel to the wing chord. I suppose that it was easier to put together the wing spars and fuselage bulkheads when they shared the same technological bases). (In the SBD, like in the earlier Northrop designs, the center wing panel and the fuselage form a single unit. Instead, they are perpendicular to the fuselage centerline. For example - its wing spars are not perpendicular to the wing airfoil chord. The Dauntless inherited many solutions from its Northrop Delta lineage. (Their number corresponds the number of the leading edge vertices - I will explain the reason further in this text). As you can see in the enlarged fragment of Figure 12‑2, it forms a small wedge with rounded corner. I tried to determine its radius from the photos. However, in the real airplane it was rounded because of the technological reasons. The theoretical shape of the NACA-2415 airfoil has a thin, sharp trailing edge. (In this image you can see that the vertices lie on the rib contour, because the mesh drawing mode there was switched to draw the resulting surface): Figure 12-2 Shaping the wing root airfoil (NACA 2415) The edge vertices are its control points, so I can easily shape this contour. The shape of a single edge loop smoothed by this scheme is a piecewise Bezier curve (or, if you wish, a NURBS curve – this is just an alternate math representation). I smooth most of the model meshes with Subdivision Surface modifier (it uses the classic Catmull-Clark scheme). (For this purpose I draw the shape NACA2415 airfoil on the reference drawing). I started modeling the wing by forming the contour of its root rib. If you want to check details of this setup, here is the original *.blend file. However, I have no experience with the Blender Units setting, so I left them set to None. Because in the SBD drawings that I have all the dimensions are in inches, I decided to assume that 1 unit in this Blender scene = 1 inch on the real airplane. This is also the moment to determine the “scale” of this model. They appear just when I set appropriate projection. Using them, I can assign appropriate image to the corresponding view, and simultaneously use all the six views (bottom, top, left, right, front, rear). I started by setting up the initial scene in Blender (Figure 12‑1): Figure 12-1 Initial setup of the reference images (in Blender)Īlthough Blender allows for arranging the reference drawings on the three perpendicular planes like in the 3D Max, I prefer the alternate way: the Background images feature.
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