(click here to get to DAVID 2.x User Manual)
Open the 3D Laser Scanning menu. The camera settings should switch automatically to your last scanning settings (or some defaults), resulting in a very dark or completely black image.
Put the object back into position without moving the camera or the calibration panels. Place the side that you want to scan towards the camera.
Switch on the line laser and project the line from above or below into the scene just as you would do when scanning. Adjust the focus control on the laser housing to make the laser line as distinct and as thin as possible. Please note that the width of the laser line changes with the distance to the object.
Watch the live camera image. Adjust the settings so that it is very dark with (almost) only the laser line visible. In particular you should choose a very low Exposure. The laser line should not be over-saturated – red or green or bright gray, not bright white – and as thin as possible on the object. Usually you will only need to adjust the Exposure, which you can do at the top right of the DAVID window. If you want to adjust other settings, click “Property Dialog”.
It is usually recommended to darken the room somewhat. Your camera image will ideally now look like this:
You can zoom into the camera image to observe the laser line: Right-click into the camera image to focus on the area of interest, then use the mouse wheel to zoom and the left mouse button to scroll. Click “Fly to live” to get back to normal view.
Turn off the laser and click Start.
Hold the laser at a considerable distance above or below the camera. Turn the laser on again and guide the laser line slowly and evenly over the object. The laser line must be visible to the camera on the object and on the left and right calibration panels at the same time. As you do so, view the display in the Scan result window. Sweep the laser line slowly over the object until you are satisfied. A very slow movement of the laser that sweeps over the entire object once is better than frequent up and down strokes.
If the software is unable to accurately follow the laser line during the scanning operation, a message will be displayed in the DAVID window (e.g. “line not detected on the left side”). Beware of this and if necessary correct the laser accordingly (position, distance, direction, rotation).
You do not need to fill all gaps in the scan; missing data will be interpolated. When you are done, turn the laser of or move the laser line slowly out of view. Then click Stop.
DAVID will immediately compute the 3D model and show it. You can rotate it with your mouse (right button) and zoom as usual. Please note that you are still watching the same 3D scene as before, just with the calibration panels, camera etc. faded out. You can use the buttons at the top to adjust the 3D view as you wish.
You can use the Interpolate and Smooth filters to adjust the result mesh. However you should not smooth to much; surface noise can be decreased with better scanning conditions or later in Shape Fusion.
You can now grab a texture.
The scan can now be saved as a .OBJ file. You can also Forward the scan directly to the Shape Fusion window, in order to combine it at a later time with other scans from various perspectives.
If you want to scan other surfaces of the object or to create an all-round scan, turn the object by hand to make the next side visible to the camera. Delete the scan with the Erase button and repeat the whole scan procedure. In this way you can completely record the object's surface step-by-step.
Please note that the individual scans should overlap, as overlaps are important for alignment and merging (Shape Fusion).
