What determines U direction, V direction?

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Permalink Reply by Danny Boyes on July 8, 2010 at 10:32am

As far as I understand it.

If you are creating a Srf from four points then the U direction is from point 0 to point 1 and the V direction is from point 1 to point 2. Therefore if you want to replicate the xyz axes directions you should start at your base point click the +ve x direction first then the +ve Y and going around in an anti-clockwise direction will result in the normal in the +ve Z.

Edge Srfs are slightly different the first curve you select is the V and the next is the U. Which is basically the same as Lofting, the section curves will be the V but depending on the end of the curve you select determines the V +ve direction. The U direction is determined by the direction you select the section Curves in.

Edge Srfs directions are determined by the first curve's direction and where is in relationship to the others i.e. to the left +ve U is +ve X and vise versa, it doesn't matter whether you pick them clockwise or anti-clockwise.