If you have questions, talk to Mac Mason (mac@cs.duke.edu)

LMS-Z390

Guidelines for acquiring a laser scan

Connecting the Riegl to the PC

  1. Connect the green ethernet crossover cable directly to the ethernet port on the PC
  2. If Windows shows a "Limited or no connectivity" icon (yellow triangle w/exclamation point) in system tray, then the IP address of the PC must be manually configured:
    • Start Menu -> Control Panel -> Network options
    • Open properties dialog for the local area connection to which the Riegl is connected
    • Select "Internet Protocol TCP/IP" and click "properties"
    • Set manual IP address to "192.168.0.1" and subnet mask to "255.255.255.0" (default gateway can be left blank)
  3. The following ports must be added as exceptions to Windows Firewall ("Advanced" tab -> "Firewall Settings" in local area connection dialog)
    • 20001 (laser data)
    • 20002 (Riegl control commands)
    • 20003 (camera data)
  4. Power on the Riegl by flipping the switch on the power supply -- the Riegl is automatically powered on when when externel power is supplied. The Riegl should beep and the scanner moves to a "park" position.
  5. Verify that the PC can communicate with the Riegl
    • Start RiSCAN PRO
    • Tool -> Scanner Configuration
    • On the communication tab, "Network (TCP)" should be selected. The default IP address is "192.168.0.234" and should work. If it does not, you can force the Riegl to reset its IP to this by turning off the Riegl by pushing the power button (underneath the scanner, near where the TCP/IP cable and power cables are plugged in), and then pushing the power button and holding it in for 5 seconds (the Riegl will make a different sound to confirm that the IP address is reset)
    • Click on the scanner configuration tab -- the software attempts to connect to the Riegl. If it is unable, an error message appears. Otherwise, the scan options (e.g. start/end angles, etc) become available -- this confirms that the Riegl is connected correctly.

Connecting to a RiSCAN PRO running in VMWare

  1. Install RiSCAN PRO in your VM as you would normally. Licence keys (which you'll need during the install) can be found by starting RiSCAN somewhere else, and looking in the Help menu.
  2. Plug the Riegl's ethernet cable into your machine's ethernet port.
  3. Tell VMWare to make this a bridged (not NAT) network connection. Set your host to use DHCP on this interface (which will fail, but we don't care).
  4. Tell the guest OS to use the network settings described above on the virtual interface.
  5. Proceed as usual.

I've tested this in VMWare Fusion 3.0, running on Mac OS 10.6 (host) and Windows XP SP3 (guest), and on Windows 7 (host) / XPSP3 (guest), and it works just fine. More RAM is better.

Creating a new project

The quickest way to create a new project is to copy a project template that is already configured properly.

In RiSCAN PRO,

  1. Project -> Open: C:\Riegl Scans\Default Project.RiSCAN\project.rsp
  2. If you want to use the camera, select C:\Riegl Scans\Duke_Z390... instead.
  3. Project -> Save As; enter a name and location for your project
  4. In My Computer, browse to the appropriate directory for your project and disable the "read-only" property for the project folder and all sub-folders (right click on directory -> properties, uncheck "read-only", click OK, choose "apply changes to folder, subfolders, files")
  5. In RiSCAN PRO, the "Project Manager" on the left shows the contents of the project directory.
  6. Right-click on the main project folder and select "attributes"
  7. Go to the instrument tab and verify that the IP address for the scanner is "192.168.0.234" -- if not, correct it.
  8. If using a camera, select it from the dropdown box. "Connect camera over TCP/IP" should not be selected if the camera is connected by Firewire.

Acquiring a scan

In RiSCAN PRO, the "Project Manager" on the left shows the contents of the project directory.

  1. Right-click on the "scans" directory and select "New scanposition". Enter a name and description, if desired
  2. Right-click on the new scan position and select "New single scan". This brings up the scanner configuration dialog box
  3. Enter the scan parameters. For a quick 360 degree scan of the area, click on "Overview". The "online view" drop-down lets you select how you want to visualize the data as the scan is being completed. For a more complete description of these parameters, see Part IV: Data Acquisition (page 77) of the Riegl user's instructions
  4. Click OK and wait for the scan to be completed.
  5. When the scan is completed, the data can be exported to ASCII format by right clicking on the file and choosing "export"

Using the Camera

Make sure you've started with a project that has the calibration for our Camera (a Nikon D200). It's in C:\Riegl Scans\Duke_Z390..., or on the "Duke Calibration Data" CD in the DVD case in the front of the binder. The other default project has a calibration for a Nikon D100, which we don't have.

When in image acquisition mode, make sure the camera calibration set is NOT for the D100. Select the D200 Calibration. The camera mount can be any setting.

So far as I can tell, you'll need to set the aperture and exposure time manually. I found a good combination by trying fifteen or twenty different combinations, and (manually) taking a picture each time. Then I pulled the images from the camera using Windows' built-in camera support, picked the image that looked best, and looked up the settings in the EXIF header (Irfanview -> Image -> Information -> EXIF).

Scanning Overview

Singlescans: Creates quick view of the range. 3D models of objects at scan time.

Scansequences: Keeps continuing to scan and filters about moving/blurring objects.

Tiepointscans: Scans that focus on high resolution around reflectors.

You can use image acquisitions on any of the scans above.

Rectifying multiple scans

The Riegl software has the ability to rectify multiple scans using corresponding points (which RiSCAN calls "tiepoints"). The documentation seems to indicate that there are other ways of doing this, but this seems to be the path of least resistance.

Before you start:

Cover your scene with retroreflectors; try to get some good 3D coverage, so you don't get degeneracies in the mathematical solution. Note that you can pull the back off the reflectors to expose a stick surface; don't do this. These cost about $1 apiece, so just stick 'em on with scotch tape. Also, housekeeping has been known to steal them, so don't leave them in public without signs.

Repeat the following for each scan you take:

  1. Create a new Scanposition. (See Acquiring a scan, above) Do this every time you move the scanner.
  2. Take your scan. I suggest using the camera, as discussed above.

Next, pick which scan should provide the global coordinate system. (It looks like RiSCAN might let you provide a coordinate frame that isn't attached to a scanner position, but path of least resistance) Do this by right-clicking on your Scanposition and selecting "Registered". (After all, a single scan is registered with itself)

Next, we need to add tiepoints. Right-click on your scan, and look for "Extract reflectors", or something like that (I'm not sitting in front of the Riegl at this instant). This will find all of your retroreflectors, plus some false positives. They'll go in the tiepoint list, as described in the manual paragraph, next.

You can also add points by hand. The easiest way to do this is to is to view your scan in 2-D (right-click on the scan, click view, and pick 2-D). Add a tiepoint by clicking on your point, and then right-clicking and click "Add". ("TPL" is short for "Tiepoint List"; each scanposition has its own list of tiepoints) I suggest sticking with the default names; this will make associating the points easier later on. If you make a mistake, clicking on the Scanposition's TPL (in the "Project Manager") will let you delete points.

Once you've done this for two scenes, open the TPL of the un-registered scene, and click the "find corresponding points" button. (Which looks like a northeast-pointing arrow between two points); select the checkbox for the scene you already declared registered (uncheck the "Control points only" option), choose the "name" radio button, and go.

To view your registered scenes, create a new Objectview (right-click on views and create a new one) and then drop both scans into the view; from the view's dialog, you can turn different scans on and off, change their colors, and so on.

Turning off the Riegl

  1. Flip the switch to the off position on the power supply
  2. If using a camera, be sure to turn it off as well