topic Point cloud error when inserting into inventor in Inventor Forum

Point cloud error when inserting into inventor

Anonymous — Thu, 14 Sep 2017 15:03:42 GMT

It's worth mentioning before I start that I'm no expert on point clouds.

So I have received a few point clouds from our client. I have used large scans on area 1 of the site with no problems. I have now moved on to a area 2 but the scans have been provided by the same client.

When I imported area 1 scans into inventor, I could zoom into the scan and be able to see all the points in that area.

When I imported area 2 scans into inventor, I could zoom and the scan basically disappears or organises all its points into vertical lines (almost like a bar code)

The strange part is that when I view the scan files from area 2 in recap, they work fine and as I would expect it to... with all the detail I need.

I haven't created the .RCP files myself but some scans have the following file formats in the support folder: .RCS, .THUMBNAIL, .TEMP16, .TEMP27, .DIFF, .LLT, .RCC Where as other scans just have one single .RCS.

This doesn't seem to make a difference to weather the point cloud has this problem or not.

The other thing worth mentioning is the edit attached data points are reasonably similar. The image with 9.79m points is area 1. The point clouds are roughly the same size so I wouldn't expect this to cause a problem. I know the attached points changes depending on how close to the scan you are so I took that with the full view of the scan filling the screen in both instances.

I have also tried creating a new recap project and inserting all the area 2 support files, saving and importing this into inventor which also did not work.

The biggest problem is when the area 2 scan is sorting it's self into a barcode like structure, the dimensions are aren't reliable. There is a bridge in one of the scans that is 2000mm wide when I measure in recap & when I measure it in inventor it's much nearer 2100mm. When I have taken my measurements I have cropped as much of the scan away so it's as accurate as it can be. I have also tried it in front view and the top view and got the same results. This is quite worrying as 100mm can make all the difference.

I'm quite lost with this one and all of the variables seem to be the same so I don't understand what the problem is. Any help would be greatly appreciated.

Re: Point cloud error when inserting into inventor

dgorsman — Thu, 14 Sep 2017 16:40:08 GMT

Laser scans of facilities are typically done with geodetic coordinates so they can be properly tied to a surveyed site marker. For surveying and processing software (like ReCap) this is rarely an issue, but with engineering software the large coordinate values frequently cause problems.

Whenever we have a laser scan done, we specify that the point cloud is registered to coordinates with "reasonable" values; anywhere from 4 - 8 locations is best. Typically that's a simple plan drawing with easily located points such as building corners, and the coordinate values they should be at.

Re: Point cloud error when inserting into inventor

Anonymous — Fri, 15 Sep 2017 07:02:16 GMT

The scan I am having problems with is 40x20m in plan view where as the one the works is 50x30m and much busier. I tried cutting most of the scan out on recap to see if I had more points when I imported it back into inventor which didn't work.

Am I just going to have to resign to the fact that there is no solution with the current scan & other than a rescan of the area, in smaller increments?

Re: Point cloud error when inserting into inventor

bob_holland — Thu, 28 Sep 2017 23:27:54 GMT

@Anonymous

I am wondering if the issue is that the space that you are trying to occupy is greater than our precision:

https://knowledge.autodesk.com/search-result/caas/CloudHelp/cloudhelp/2017/ENU/Inventor-Help/files/GUID-84623939-38A8-49BF-8D97-BB9DA3697056-htm.html

Please check the above article and see if the distance to the Assembly origin is greater than 100 meters.

Based on your attached image of:

The distances in the dialog box is much larger than 100 meters.

Thank you.