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Pratyeka
10-21-2010, 02:56 PM
My question is: can you import a stl model and extract only a portion of the whole? for example: I have a 3D model of a head, but I want to carve only the nose. Can I cut out a square section that would include only the nose and whatever area inside the square?

dbfletcher
10-21-2010, 03:10 PM
I'm thinking "yes" on this one. You can slice on any plane you choose... so you can always "slice" away the parts you dont want and discard the slices before making them in to patterns. The one tutorial video with the car I think kinda shows this. I dont think you can just select an area to apply operations to just that area, but you can get the end result you are looking for.

jpaluck
10-21-2010, 04:23 PM
try the demo version..you should be able to see if does what you want...you should have no problem slicing the nose for example

eelamb
10-21-2010, 05:23 PM
I would slice off everything on the left, right, top and bottom of the nose. Leaving the nose alone, then slicing that off the section left. You can un-check the other slices and only import the slice you want.

example:

Pratyeka
10-21-2010, 07:04 PM
I would slice off everything on the left, right, top and bottom of the nose. Leaving the nose alone, then slicing that off the section left. You can un-check the other slices and only import the slice you want.

example:

That is exactly what I had in mind. now, if there was a quick and easy way to separate the whole head into sections, a bit like slicing the Earth along longitudes and latitudes, then take all the individual sectors and carving those. You could then assemble all those sectors to build the head in 3D. You would of course need to sand the edges at the proper angle for them to fit.
You could apply this technique to anything 3D, from a baseball to a chinese puzzle ball...

I'll have to play with the demo.

eelamb
10-21-2010, 07:18 PM
Pratyeka, you can do just that. Takes a little thought as to how to slice each section, so you do not loose parts due to how it was sliced. For example, top of the head as one slice, left side and right side as another slice. back of the head and then the face in 2 or more slices. You have to think of how the slice will carve. Anything on the sides will not carve, so try to make sure you have slices with carveable areas. Thus slice, look at the slice, if not right undo, and slice a different way.
The tuturial provided by LHR shows a slicing of a head. It takes time but can be done.

Pratyeka
10-21-2010, 09:01 PM
yep, just played with the demo. it is doable, but I can see that the software is optimized toward making successive slices in one direction easily. Splitting a sphere into sectors (like an orange) is harder because you can't lock the axis of the slicing plane. it moves with every slice. So it would be hard to get precise sectors.

eelamb
10-21-2010, 09:29 PM
I see what you mean, but the object can be rotated. An orange would be 2 slices on each of the 6 sides, leaving a square, or hollow center. Thus you have 12 carves, that once assembled becomes a hollow orange.

Pratyeka
10-22-2010, 09:11 AM
this is a picture of what I want to achieve. Any object that is roughly spherical could in theory be sliced this way and then carved on one flat board. Each edge would have to be beveled to the proper angle before assembly.

liquidguitars
10-22-2010, 10:47 AM
How about just saving out each slice of the object " just need two" in your 3D program after rotating and extruding then.

Pratyeka
10-22-2010, 11:54 AM
that would be fine for a smooth sphere. For a head or a chinese puzzle ball (http://www.antiquehelper.com/item/330853), or anything not uniform, every piece needs to be carved. For the above example, two pieces repeated 16 time.