Not my first 3D carving...

[tblough]

Acorn can, most definitely, probe and create a cloud of points of the surface. It is up to your CAD program to take that cloud of points and turn it into a surface that is usable. This is by far the most difficult item to execute and not easily done in most CAD packages.

[Leo Voisine]

Tom,

I really like your byline

What are cloud points? Are they X-Y Z coordinate positions?

[tblough]

Leo - yes, a point cloud is just a collection of points in space with x, y, and Z coordinates. Here's an interesting paper describing the problem:

FROM POINT CLOUD TO SURFACE; THE MODELING AND VISUALIZATION PROBLEM.pdf

(2.57 MiB) Downloaded 136 times

[Gary Campbell]

Hi,

My question is - Can I probe the top - rough - surface and create a "modeling" surface using CNC 12 Pro - Acorn BOB - and create an STL, or whatever surface that I can project to 3D surface in Aspire.

Yes, but there is a couple steps involved and a caveat.

Caveat first: A 3D probed surface will be at an extraordinarily low resolution for even Aspire, so in most cases a 3rd part program is needed to smooth out the surface and create a model with the expected resolution. You may already use one of these software programs.

Centroid's grid probing will give you the point cloud (3D points) that you want. Paul Rountree has written a gadget that will import a 3D point cloud, but you will have to convert the Centroid "digi" file into one that his gadget can read. I have a version that direct imports 2D points into vectors, it was modified from Paul's original. If I remember correctly, I took the "digi" file into Excel, removed the axis letters and exported it as a comma delimited file.

[Leo Voisine]

I can "smooth" it out in Aspire once it is a model component.

I will look into what Paul Rountree made for a gadget.

[Leo Voisine]

Leo - yes, a point cloud is just a collection of points in space with x, y, and Z coordinates. Here's an interesting paper describing the problem:

FROM POINT CLOUD TO SURFACE; THE MODELING AND VISUALIZATION PROBLEM.pdf

Tom,

That's a fair bit of technical reading there. I need to be in a more comfortable position before I dig into that one.

I have saved the PDF and I will refer to it.

[Leo Voisine]

Ahhhhh - I think I have something.

There IS a gadget in Aspire to take point cloud data and convert to a surface.

Whereas I no not yet have Centriod I cannot test the gadget.

Would it be too much to ask if anyone has a point cloud file that I could test with? I don't need anything fancy or proprietary - just some data points.
I would greatly appreciate it. This will also help me in deciding if I can use the probing in a way I want to.

[tblough]

I don't know what the digitized item is, but the attached file is one included with the Centroid Software

20r.zip

(77.88 KiB) Downloaded 128 times

Be sure to read the Digitizing section of the Centroid Mill Operators Manual
viewtopic.php?f=60&t=3397

[Leo Voisine]

tblough

Thank you.

That file is all G-Code, not really what I was expecting as point cloud data, which is a comma delaminated format.

BUT - I think I need to maybe reevaluate my expectations. Maybe it is easier to get a surface with that DIG file.

Leo

[tblough]

I guess it is all G-code in the fact that the first line contains a G1. Everything else is point triplets. One minute with a text editor will strip out any "g-code" and replace the "X", "Y", and "Z"s with commas. Or, you can use the DIG to CAD function from the Mill manual I suggested you read:

Code: Select all

The Dig to CAD feature of the CNC software is used to export digitized files for
 use with CAD/CAM software. The digitized files are converted to point cloud data that 
 is easily readable by most CAD/CAM systems. Digitized files have either a .DIG or 
 .DIG5 extension. Files with the extension .DIG are created from the grid or wall 
 following digitizing routines, while .DIG5 files are created from 5-axis digitizing
  toolpaths. The resulting point cloud data files will have the same file name as the 
  .DIG and .DIG5 files they were created from, only they will have a .TXT extension. 
  These files can then be imported into any CAD/CAM software or viewed with a
   simple text editor.