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

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.

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

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

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...

"""""Also, how can I blend the surfaces of the (blending.3dm)?""""""""

Well, it depends.. Is this what you were expecting to see as a result??

Hi Ramon,

> Also, how can I blend the surfaces of the (blending.3dm)?

You've got several of the original construction curves in there - in order to do a surface blend you need to pick edges of the surfaces but that will be difficult in your model there directly since the original construction curves are overlapping right over top of the surface edges.

So hide or delete those construction curves to get them out of the way and that will make it easier for you to select the surface edges to blend between.

- Michael

Hi all,

Thanks for the info. A few basics that eluded me.

Seem to be getting the hang of it.

Appreciate all the help.

Ramon