Make a 3D from a contour

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Romeo4755
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Joined: Sat Jun 03, 2023 9:38 pm

Make a 3D from a contour

Post by Romeo4755 »

Hello.
I understand that my question is extremely unprofessional but I ve been looking through tutorials for 3 days and still haven't figured out: can I make a 3D-model without building all curves and lines, just from an outline of a photo? I need to make an obj-file of an axe head and it doesn't need to be precise. Is there a method the outline will be just automatically repeated in FreeCAD, extruded and exported as OBJ?
Thank you in advance if you can tell me.
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NewJoker
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Re: Make a 3D from a contour

Post by NewJoker »

You can import this picture, scale it and draw over it using splines in the sketcher but you will still have to add the 3rd dimension to it and that’s the tricky part.
chrisb
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Re: Make a 3D from a contour

Post by chrisb »

You can use Inkscape to trace the image automatically, but as NewJoker said: you have to add the third dimension.
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jeno
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Re: Make a 3D from a contour

Post by jeno »

Romeo4755 wrote: Sat Jun 03, 2023 9:50 pm Hello.
I understand that my question is extremely unprofessional but I ve been looking through tutorials for 3 days and still haven't figured out: can I make a 3D-model without building all curves and lines, just from an outline of a photo? I need to make an obj-file of an axe head and it doesn't need to be precise. Is there a method the outline will be just automatically repeated in FreeCAD, extruded and exported as OBJ?
As NewJoker already mentioned the 3rd dimension is the tricky one. For a tracing with inkscape the template isn't that good to get a good result.
Anyway...this seems to refer to an dagger-axe.
From my pov it is easier to start from scratch. My most likely guess...
dagger-axe.png
dagger-axe.png (19.52 KiB) Viewed 1307 times
cheers
Romeo4755
Posts: 13
Joined: Sat Jun 03, 2023 9:38 pm

Re: Make a 3D from a contour

Post by Romeo4755 »

NewJoker wrote: Sat Jun 03, 2023 10:19 pm You can import this picture, scale it and draw over it using splines in the sketcher but you will still have to add the 3rd dimension to it and that’s the tricky part.
Thank you for the answer.
Why are you saying hat adding 3rd dimension is tricky? Isn't it just extrusion with given depth?
Drawing over an image using FreeCAD sketching methods, this is what I am trying to avoid. I want to import an outline as a ready outline for my future part - with details and irregularities, then extrude it and add/ subtract bulging places and the sharp edge.
Romeo4755
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Joined: Sat Jun 03, 2023 9:38 pm

Re: Make a 3D from a contour

Post by Romeo4755 »

jeno wrote: Sun Jun 04, 2023 8:26 am As NewJoker already mentioned the 3rd dimension is the tricky one. For a tracing with inkscape the template isn't that good to get a good result.
Anyway...this seems to refer to an dagger-axe.
From my pov it is easier to start from scratch. My most likely guess...dagger-axe.png
Yes, it is what you call dagger axe.
Romeo4755
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Joined: Sat Jun 03, 2023 9:38 pm

Re: Make a 3D from a contour

Post by Romeo4755 »

chrisb wrote: Sat Jun 03, 2023 10:30 pm You can use Inkscape to trace the image automatically
Can then I import the outline into FreeCAD to make it make future detail without further sketching in this 2 dimensions?
GeneFC
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Re: Make a 3D from a contour

Post by GeneFC »

Romeo4755 wrote: Sun Jun 04, 2023 11:03 am Can then I import the outline into FreeCAD to make it make future detail without further sketching in this 2 dimensions?
If the image shown in your first post is the real object to be traced, then any technique will end up as garbage. Lots of rough edges and gaps.

You will almost certainly need to do a bit of work in Inkscape or FreeCAD to clean up the shape.

Frankly it would be easier and more successful to simply trace over the image imported into FreeCAD. Then you can make smooth curves during the trace.

I have tried your proposed approach in the past, and it simply does not give a useful result.

Gene
Romeo4755
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Re: Make a 3D from a contour

Post by Romeo4755 »

GeneFC wrote: Sun Jun 04, 2023 2:04 pm If the image shown in your first post is the real object to be traced, then any technique will end up as garbage.
Of course, I am not talking about all black shadows and spots, just the OUTLINE. I would have made a more explicit image but i still don't understand whether it is of any use and, if it is, what are the requirements.
Talking of Inkscape, does it need to be vector? Does it need to be of certain line thickness?
Or is FreeCAD unable to scale the curves so anyway I would have to put measurements for every tiny curve by hand before extruding it?
GeneFC
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Re: Make a 3D from a contour

Post by GeneFC »

Romeo4755 wrote: Sun Jun 04, 2023 3:40 pm Of course, I am not talking about all black shadows and spots, just the OUTLINE.
That is exactly what I am talking about as well. Take a good look at the upper right end. Very rough.

If that is acceptable, fine.

Just do not expect it to become smooth in the manner that Jeno showed.

Gene
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