Tangency between mirrored surfaces

 From: mcdrury 17 Sep 2011  (1 of 8)
 Hi all, Just wondering if there is a explanation to rectify to the problem I seem to be having? How can I remove any ridges that are formed by the mirroring of two curved surfaces? Is there a way to create tangency with the other surface? I'm basically drawing one half of an aircraft fuselage and when I mirror it I end up with a ridge running along the top and along the bottom. Thanks Ramon

 From: BurrMan 17 Sep 2011  (2 of 8)
 4516.2 In reply to 4516.1 Hi mcdrury, You have to draw your curves with tangency ending in the mirrored direction.. If you turn on show points on your curves and make the last 2 points of each end of the curves point tangentially in the mirror direction, you will have a tangential connection.

 From: Michael Gibson 17 Sep 2011  (3 of 8)
 4516.3 In reply to 4516.1 Hi Ramon - yes like Burr mentions when you draw the curves for your shape you want to pay special attention to the first 2 and last 2 control points - the line between the ending 2 control points is what defines the direction of the curve tangent and so if you're going to mirror the results later you want to make sure the curves you are constructing things with have a horizontal tangent. If you're still having difficulty maybe you can post your 3DM model file so we can take a look at your model. Also depending on how you are building the surfaces it can sometimes be good to build a larger surface all in one go instead of building half and mirroring it - see here for some examples: http://moi3d.com/forum/index.php?webtag=MOI&msg=1398.18 http://moi3d.com/forum/index.php?webtag=MOI&msg=1398.19 The other ways that you can get smoothness is by leaving some space between objects and using the Blend command which puts in a smooth connector surface in between the space between 2 edges, or by building things with some initially sharp corners and then using fillets to smooth them out. - Michael

 From: mcdrury 18 Sep 2011  (4 of 8)
 Hi all, Based on the remarks from BurrMann and Michael, I was able to loft the fuselage to a satisfactory conceptual stage which is great. It needs a bit more work but I was starting to understand the curves better. I was then working on the wing root and was wondering if the model attached is correctly modeled as per BurrMann's comments regarding tangency at the mirror point? I'm not sure I really understood what was being said, but my interpretation is attached (root.3dm). Also, how can I blend the surfaces of the (blending.3dm)? Thanks for any assistance Ramon Attachments:

 From: BurrMan 18 Sep 2011  (5 of 8)
 4516.5 In reply to 4516.4 Hi mcdrury, """"""""""""I was then working on the wing root and was wondering if the model attached is correctly modeled as per BurrMann's comments regarding tangency at the mirror point? I'm not sure I really understood what was being said, but my interpretation is attached (root.3dm). """"""""""""" Yes it is correct. The 3 points you have in alignment there at the leading edge create a tangent connection between the surfaces. You have them relatively "close" to each other, which will make the connection "look harder" on the surface. If you delete those 2 closest to the center point, then use the next 2 back and align them with the leading edge, you will see a much more gradual, smooth curve of the surface.. If you are looking in the front view, as soon as you move either of those 2 points left or right in the view, you will have a "hard edge" or a seam there... EDITED: 19 Jun 2012 by BURRMAN