Full Version: Blending Shapes

I've been branching out in Moi3D from CNC router cut creation into more complicated 3D surface modeling. I have a basic handle on the tools available for creating surfaces but am struggling with intersecting and blending surfaces. See the airplane cowl bellow. It's formed with two large shapes: the spinner radius flow back into the cowl and the main cowling body. I want to intersect the two surfaces, keep the distinct body line that union forms, but create blending fillets to merge the surfaces. I do notice how important it is to keep even and well formed surfaces to have any hope of interesting them and forming a fillet.

Can I create a single surface from two rather than a joined surface?

If I use the boolean to cut a profile out of a surface it's often very complicated with many points forming the newly created edge. Is there any way to simplify this edge and directly manipulate it like the surface profile points?

I'll continue to dig in on YouTube and here no the forum, but any guidance is appreciated!

Craig

Image Attachments:
Cowl 1.png  Cowl 2.png 

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Can you post the .3dm files, please?

-Brian

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Brian,

Here you go. I have different styles with the surfaces in different stage. I worked on it a little more and had some better luck. It seems like the filleting if very sensitive to surface shapes. It's also a little challenging to intersect those two shapes with how the main cowling rolls in the front.

Craig

Attachments:
Moi3d Forum Cowling.3dm

Image Attachments:
Cowl.png 

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Hi Craig,

re:
> Can I create a single surface from two rather than a joined surface?

Generally no not after they're created. But if you are generating a joined surface result from something like sweep, loft, extrude, ... then controlling the structure of the input curves can help to avoid split up result pieces.


> If I use the boolean to cut a profile out of a surface it's often very complicated with many
> points forming the newly created edge. Is there any way to simplify this edge and directly
> manipulate it like the surface profile points?

Do you mean you want to manipulate just the edge as an independent curve or do you mean you want to manipulate the edge and have the surface be modified as well?

For the first, set up a keyboard shortcut with Rebuild for the command name and run that on your curve.

For the second it basically doesn't work that way because trim boundaries don't control the surface shape directly, it's more like they live on top of the surface and mark which areas of it are active and which are holes.

- Michael

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Hi Craig, in the .3dm file you posted it looks like you've got things intersected and filleted there. Is there a particular problem area with it now?

- Michael

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The other thing you can use aside from filleting is Construct > Blend. For that you cut away open space so you don't need to make things intersect, then Blend between the open edges.

- Michael

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I'm embarrassed to say it, but this I the first time I've figured out how to use the Blend tool, it works great for this application. I set the snapping to surface and drew a line along the profile to form that edge. It doesn't follow the surface perfectly but close enough that the trim command cuts a nice clean edge. Then I used the blend tool and that got me most of the way. I turned on the surface points and drew a swooping line along the flowing ridge of points, skipping the ones out of alignment. After that simply snapping the surface points along the smoothed curve cleaned everything up in that compounded area.

Thanks for the help, this is excellent!

Image Attachments:
cleaned up.png  Cut lines snapped to surface.png  guide lines 2.png  guide lines for surface points.png 

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I'm starting go get a better handle on the blend command. I can see now what your were talking about on the surface and boundaries forming the edge.

Curve network sure does a nice job. If you take create accurate and smooth curves from the beginning it translates into some very nice surfaces. I need to dig in the forum and YouTube to better understand what you can and can't do with it.

Thanks again.

Image Attachments:
Front.png  Ground.png 

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"For the second it basically doesn't work that way because trim boundaries don't control the surface shape directly, it's more like they live on top of the surface and mark which areas of it are active and which are holes."

If the shape data is retained when a portion is trimmed out of a surface (creating this inactive area you mentioned) Is there some kind of heal command that would remove this inactive area? Returning the surface to its full shape? I hope that makes sense.

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Hi Craig,

re:
> If the shape data is retained when a portion is trimmed out of a surface (creating this inactive area
> you mentioned) Is there some kind of heal command that would remove this inactive area?

There is indeed, it's called an "untrim".

It's done by selecting all the edges that make up a trim boundary and doing a Delete. The trim boundary must belong to a single surface, if there are multiple surfaces that are joined together use Edit > Separate on them first to break them into individual separate surfaces.

Some more description of untrim here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=444.4
http://moi3d.com/forum/index.php?webtag=MOI&msg=9671.5

and also in the Object Repair tutorial here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=446.17

- Michael

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Got it. Hidden right there in the delete key. That is very cool, works great. I like the ability drag a window once in sub-object mode, here I've been selecting one at a time. Thanks!

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