Using Meshlab to Clean and Assemble Laser Scan Data

Meshlab is an open source software program used to manipulate and edit mesh data. This tutorial will specifically show how to assemble, clean and reconstruct data from a 3D laser scanner. The techniques used with the scanner used here should apply to scan data from any machine, but first read any documentation included with your system before beginning.

One must use their judgement when scanning the object to be sure to capture enough data to create the best mesh possible. The alligator head used here required around 30 scans taken from various angles. The number of scans would have been greatly reduced if a rotary turntable was used, but the assembly technique remains the same. Unfortunately, Meshlab does not currently include an Undo feature, so it is important to save different versions of your work and to do so frequently.

Step 1 Cleaning Scan Data

Start by opening the first scan file. Chances are high that the object will be surrounded by a lot of extra data that does not need to be included in the final mesh. The easiest way to remove this data is to use Select Faces in a Rectangular Region tool. It allows you to use a marquee style selector to choose faces that you would like to remove. After selecting them, go to Filters/Selection/Delete Selected Faces and Vertices to remove them. This not only deletes the faces, but also removes the underlying point data, resulting a a cleaner mesh and smaller file size. Repeat this step for every scan and it is helpful to save the clean file as a new version, leaving the original intact. Save often!

Comments

[jam BD]

Absolutely amazed by the results.

[Dentroman765]

 I'm happy to say that you've succeeded in your goal of getting people interested. Following this tutorial, I built my own scanner...I'm making an instructable and I'll post it soon. Meshlab had worked pretty well for me so far!

[kelseymh]

Very nicely done. This "could" have been considered referral-spam, but you've done a great job at putting together a useful and general tutorial without flogging your own product :-)

[3rivers3d]

Thank you. The goal was not to push a certain product, but to get people interested in scanning. These techniques can be used with any system from a David Scanner on up. If you can not tell, I REALLY like Meshlab which is a great tool and open source to boot!

[kelseymh]

I definitely could tell, and I also learned that 3D modelled was much more complex and human-intensive than I had realized.