3D modelling

[jamie1979]

Hey everybody,
maybe someone can help, I'm not very familiar with 3d modelling. I'm in contact with a professor at University of Wales regarding software for visualising 3D point clouds captured with a terrestrial laser scanner. He needs a model of the feature rather than the raw ascii data I sent him, and he suggested that AutoCAD should be able to convert the point set into a polygonal model. The point set contains approx. 20,000 points. I'm currently using AutoCAD 2006. Any tips would be greatly appreciated.
jamie

 

[TCARPENTER1]

Hi Jamie,

AutoCAD by itself isn't capable of converting point clouds to vectors, you'll need an add-on program to accomplish this. There are several out there here's one: Point Could for AutoCAD. Google "point cloud AutoCAD" and you'll come up with several.

HTH
Todd

 

[cfee]

Ok- I'd DEFINITELY look into the Point Cloud for AutoCAD link supplied. If the cost or complexity is beyond your current plans, I'd let basic ACAD out of the box solve the point cloud issue for you. I'm tempted to see what stopping the post at this point would return as repsonses, but I'm maybe not that bright.

The process isn't short and quick, but it works.

Here goes:


Open windows notepad (I already know- everyone has their favorite ASCII editor. We also all own notepad, and it'll do fine for this problem.) Minimize it. Then-

Open the xcel spreadsheet you used to collect and collate your data. See the 1st column? Is that the X values? If not, one of the 3 is. One is the Y values, and one is the Z values. It'll be easiest if you get them in X,Y,Z order.
Then sort them in any order you want descending, ascending by color (just kidding), whatever. The result should be 3 columns of numbers. Format them as simple numbers, with as many decimal places as you want. X, then Y, then Z.

Add a 4th column before the X with the word POINT all the way down.

Swipe all 4 columns, and place them in your session of notepad

The result shgould look like:
point 123.45,2344.56,456.78
point 234.56,345.67,789.01
point 345.67,456.78,567.89

and so forth. EACH POINT GETS ITS OWN LINE.

Seperate the word "point" from the first digit of the x-column with a single space, Seperate each numeric column with a comma. You've created a script. Swipe the WHOLE THING and paste it in at the command line. YOUR SCRIPT WILL FAIL AT THE FIST PLACE YOU MISSED A FORMATTING issue. You can tell by the last number showing on the command line in ACAD. use search in notepad for that exact number, find and fix your goof (usually 1 too many or too few spaces). FULLY CLEAN, YOUR CLOUD WILL EMERGE.

Finally, if this is really too much work, and all of your xcel shortcuts for pre-formatting your data for when it'll go into notepad still don't save enuff time, then the program mentioned before would be a great option. However, ~20 minutes formatting time, I can take a 200-300 point cloud, and drop it right in!

Good Luck-
C. Fee

 

[CarlB]

Ok now you have points in AutoCAD from ASCII data. I don't know if the poster didn't know how to create points, but I thought the bigger problem was how to create a "polygonal model". I believe that means a solid, or if not that some sort of surface - 3dfaces or polyface mesh. Does the 2007(?) "loft" command do that?