Creating a curved surface through Curves

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 From:  Jaysabbott
4374.1 
I have created a loft weight project but I am having difficulty creating the curved upper surface using the objects curves. I tried a loft and a mesh but I don't understand enough about how to create them or proper use of these surfacing techniques to apply them to my object. It has a base curve, a profile curve and 2 section curves. Currently I have created a solid from the base curve and the profile curve but that creates a blocky looking object instead of the object I want that uses the section curves as well.

I have attached the file, could someone show me or suggest how I should proceed to get the object I desire?

Thanks in advance,
Jay Abbott

I have added some of the source images I used to create the curves.

EDITED: 8 Jul 2011 by JAYSABBOTT

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 From:  Mike K4ICY (MAJIKMIKE)
4374.2 
Just my stab at it:

If you use just the un-closed curves making up the major profile. (I used Trim to cut your loops, so that I would have just the top side.)
You can Network mesh those. I did this and then I aligned the top three points on the mesh because the top was too pointy.
It may be necessary to do some manipulating of the mesh points also.

If you incorporate mesh curves in-between the top ridge curve profile (length) and the side flanking profiles, and if they represent where your mesh will be at those locations - or in other words: add some quarter profiles, you'll get a more accurate shape.
In the photo (looks like a chicken drumstick), I see that the side profile seems to have a more squared out (or conic) shape, while not being completely round.

You could also then use Boolean Trim to flatten the bottom if you wish.



You can still also try the Sweep function. In the following example, I used the straight line in the middle bottom as the Rail.
And you can see the profile shapes positioned along the path. For an added measure of control, I used a Scaling Rail (top middle).

I also tried adding two side profiles on the bottom and used the those two instead of the straight middle line, adding more control to the shape.

EDITED: 8 Jul 2011 by MAJIKMIKE

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 From:  Mike K4ICY (MAJIKMIKE)
4374.3 
Jay,

Here is an example where I took the two side and the top ridge long profiles, then added shape profiles placed down the line and scaled where needed.
The bottom shape was split along the middle to make two separate profile curves.
The Network mesh was applied to the set.


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 From:  Michael Gibson
4374.4 In reply to 4374.1 
Hi Jay, it can often be difficult to figure out a plan of attack when kind of blobby objects are involved.

One thing to look for can be any areas that go through a kind of a tight bend - those usually suggest that you may want to model them as sharp edges initially, and then use a fillet to round them off.

So for example the end part could fit like that:




If you don't have many areas like that you can try to build the tight areas in more directly but especially if there are several areas like that it can be easier to build them sharp to start with since that lets you pieces in separate chunks and you can then focus on a kind of smaller region of the shape at a time.


But the other end of your shape does not have anything like that, there's no tight curves, it's all quite broadly curved throughout:



So that means that you probably aren't going to put a fillet in the middle of that area there - it's going to be better to build that portion as all one big surface since it has all the same kind of shape throughout there. In your attached 3DM file you've got the intersection of 2 planar extrusions, and that will leave a big sharp edge in that area, so that's not going to be a good method for that area.

Network like Mike shows above can work, or also if you have a shape that kind of resembles a turned lathe type thing, you can use Revolve or Rail Revolve for those kinds of shapes.

With Rail revolve, you can give the revolve a trajectory curve which can be used to kind of stretch the profile as it swings around the revolve axis like this - here I've got 2 curves, the one on the bottom will be the path and the vertical hoop will be the rail curve:



Select the profile curve and run the Construct > Revolve > Rail revolve command, then the command prompt in the upper-right area of the main window will say "Select rail curve" - select the rail curve for that step. Then the next part is to select the ends of the revolve axis line, you want to put them at the ends of the profile shape like this:





That builds a turned result like so:




The 3DM model file is also attached.

- Michael

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 From:  Michael T. (MICTU_UTCIM)
4374.5 
That is so slick Michael G.!

Michael T.
Michael Tuttle a.k.a. mictu http://www.coroflot.com/DesignsByTuttle
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 From:  Mike K4ICY (MAJIKMIKE)
4374.6 
...This is one of MoI's most endearing qualities, is that there are so many ways to "skin a cat"!

....or skin a chicken leg. ;-)
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 From:  Jaysabbott
4374.7 
Thanks to everyone who offered solutions. It is so fantastic that so many people can help one another. The more I use MoI the more I like it.

Thanks again to everyone.

Jay Abbott
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