Having a problem creating a solid object

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 From:  ericb
4298.1 
I am trying to create a solid object from a series of closed curves, and I am having a really tough time.

Basically, I want to take the outline I've created and make it solid - it's a bit hard to explain, but once you take a look at the frame, you can extrapolate what the final product is supposed to look like.

I would appreciate any help on this - it's really driving me crazy!
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 From:  Frenchy Pilou (PILOU)
4298.2 In reply to 4298.1 
The little triangle are deconnected from the bottom structure!
for any reason some of your lateral curves are not joined!
make some big zoom for see it :)



You must be precise!
Disable some grid snap for keep only object snap for have good snap on extremities!
Or just grid snap and not object snap etc...

Best is redraw all the object!
Not a big deal :)

As your lateral sides are not planar you must have tensile structure
or add some lines if you want only planar facets

EDITED: 24 May 2011 by PILOU

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 From:  ericb
4298.3 In reply to 4298.2 
Thanks for the reply, Frenchy Pilou. I redrew the object, but I'm still having the same problem.

When I turn the curves into planar surfaces, all render properly except for the two side curves (see the attached file.) Is this because the curve isn't all on the same plane? I also can't get it to extrude properly - it gives me a hollow extrusion. I'm guessing the side curves are my problem, but I have no clue as how to fix them.
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 From:  Michael Gibson
4298.4 In reply to 4298.3 
Hi eric, yeah that curve won't automatically convert to a plane because it's not flat:






So you won't be able to create a simple plane surface through that non-planar curve, and if you extrude it, it won't get caps on the end because extrusion only knows how to build a cap for a planar opening (unless you extrude a surface in which case it can copy the surface to each side to make the caps).

So one way to solidify this object is to draw in some additional lines like so:




Now you can select 4 sided regions and use the Network command to fill in a surface for each region, so for example select these 4 lines:



Then run Construct > Network to build this surface:



Then go select these 4 lines and run Network again and so on:




It can be easier to build something like this by starting with a big solid extruded block and then doing booleans to carve off some pieces - that way it stays as a solid the whole time.

See this recent post for an example for how to carve off some gently rounded sides off of a block:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4296.5

Also I'll see if I can give you an example on your shape.

- Michael

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 From:  Michael Gibson
4298.5 In reply to 4298.1 
Hi eric, so the different way of creating a solid block and then carving it up would go like this - start by drawing a profile curve in the side view to get something like this:



Now extrude that to get your starting solid block:



Now you can go to the Front view and draw in some cutting curve profiles, like this:




Select the solid block and run Construct > Boolean > Difference - this will slice the block by those front profile curves and leave it in pieces like this:



Select the outer pieces and delete them to get the result:



This method tends to be an easier way to work on things, particularly when you want some kind of curvy surface portion - instead of trying to build a curvy surface to some irregular outline hole you instead want to have the curvy surface be some larger extended sheet that gets trimmed where it intersects the other shape. Using cutting and intersections as a primary modeling tool in this way is one of the biggest differences between NURBS modeling versus polygon modeling.


You can also rotate the cutting curves in the top view if you want them to cut at an angle:





If you're using a line as the cutting curve and want to make it cut at an angle, you'll need to extrude it out into a cutting surface and use the "Set dir" option in extrude to control which direction it will go in, because a line does not have a single inherent perpendicular direction like a planar curve does.

But if you want to make cuts that go straight out from one of the side views, you can draw cutting curves in those views (including lines flat in the view) to do those cuts.

- Michael

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 From:  ericb
4298.6 In reply to 4298.5 
Michael - thanks for the help. Networking those sides and then running a Boolean union kind of did the trick. I'll have to play with it a bit to fine tune the design. Thanks.
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 From:  Frenchy Pilou (PILOU)
4298.7 
Another possibilitiy for the lateral side
if you want keep the lines of the start you can take 2 segments oposited
join the other lines and make a sweep 2 rails ;)
You will obtain a tensile surface on the lateral side!

/

EDITED: 24 May 2011 by PILOU

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