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Old 28th August 2009, 04:50 AM   #1
coldby
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Join Date: Jun 2006
Posts: 102
Default controlling the extrusion centre

One more, as long as the work leaves me a few inches of loose chain

Extrude Along Path is one of the most powerful tools of AC3D, as it allows you to create any kind of complex objects out of a mere profile.
Yet it has a dark spot that makes it somewhat less versatile than one might wish : there seems to be no way to control the 'extrusion centre', i.e. the point on the "extrudend" that will follow exactly the guiding path.
Let me try to be more specific : as you extrude a surface (or its perimeter) along a path, in the resulting objects its points will become lines. Of these lines only one (or a set of parallel ones) will match exactly the original path, whereas the others will be smaller or larger according to the shape of the extruded surface.

I assume the extrusion centre above is the centre of the surface bonding box, as a few frustrating tests showed it's neither the gravity centre nor the pivot centre.

Controlling the position of this point is little relevant as long as the path is smooth and decently larger than the surface to be extruded (as in fig 1), but when the two are nearly the same size or if the path has comparatively sharp corners (as in fig 2), it may get damn important.

Does anyone know of a way around it?
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