Accurate 3D modeling


#1

I was recently approached by a guy with a Horner Brothers table.

The table was missing the left wings, and he needed it reproduced. He did have a right wing. I used 123D catch to generate the mesh and made the cam paths off of that. Is there a more accurate way to generate mesh? You can see the detail isn’t quite good enough.


(Mark Bellon) #2

Something that small can be 3D scanned and clean up.

The product I’ve used - optical scanning - and seen used - quite effectively - is this:

http://www.nextengine.com

Low end scanners and software will not come close to good enough to make the effort worthwhile. Even with a high end scanner, the clean up is going to take some time. Multi-spectral scanning leads to the best results fastest.

Another approach is a “touch probe” - mechanical scanning - to generate a “point cloud” and an STL from that. Here is one example:

http://www.centroidcnc.com/cnc_touch_probe.html

There are many others at various price points.

The optical scanning is likely to produce a better model and do so faster.

Inviting @WillAdams as I bet he knows of some good choices.

mark


#3

Anything that I can afford? < a new shapeoko


(Mark Bellon) #4

Anything that I can afford? < a new shapeoko

Accurate and time effective isn’t cheap I’m afraid.

Do you happen to be a city with a TechShop? They often have one of the high end scanners I mentioned.

A touch probe with sufficiently small probe might get you somewhat close at a low price.

mark


(William Adams) #5

I’m afraid 3D scanning hasn’t interested me much.

One free option on the wiki: http://www.shapeoko.com/wiki/index.php/CAD#3D_Scanning

and some information on touch probes: http://www.shapeoko.com/wiki/index.php/Touch_Plate#Touch_probe


(Mark Bellon) #6

I’m afraid 3D scanning hasn’t interested me much.

One free option on the wiki: http://www.shapeoko.com/wiki/index.php/CAD#3D_Scanning

and some information on touch probes: http://www.shapeoko.com/wiki/index.php/Touch_Plate#Touch_probe

I KNEW you had something in your magic bag of tricks! :joy:

mark


#7

I know you can save the probe data from bcnc, but have never tried converting that to an stl. Have you done that before?


(Mark Bellon) #8

I know you can save the probe data from bcnc, but have never tried converting that to an stl. Have you done that before?

I used the NextGen software. My CAD program can handle point cloud conversion to mesh and on to an STL file. I would check your CAD program or look for software; there are many.

mark


(Jonathan K) #9

If you have a good DSLR or mirrorless camera with high-quality glass (minimal lens distortion and abnormalities) you could try doing photogrammetry using VisualSFM and then reconstruct a mesh with CloudCompare to run your CAM on.

It’s a free workflow if you have the camera and computing hardware, and you can get some really great results, but it’s neither easy nor obvious, so get ready to dig in and learn a lot of new stuff to do it.

Here’s an example scan-reconstruction (with color):

This is of a sculpture I did a while ago that stands about 4" tall, so you can get small objects reasonably with the right lens.

:slight_smile: Good luck


(Mark Bellon) #10

Perspective from motion. Synthetic aperture too. With good lighting, good positions and sufficient views a 3D object can be reconstructed well. Nice!

Added to my things to investigate further list.

mark