Difference between revisions of "Scanning best practices"

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=== Material albedo (reflectivity) ===  
 
=== Material albedo (reflectivity) ===  
A material with higher albedo provides a better signal-to-noise ratio.
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A material with higher [[Albedo|albedo]] provides a better signal-to-noise ratio.
  
 
=== Strong ambient light ===  
 
=== Strong ambient light ===  

Revision as of 12:23, 24 August 2016

How to configure the scanner to provide the best quality

The quality of the scan depends on multiple factors. The scanner provides a variety of settings to enable an optimal scan; however, even by rearranging the positions of the scene and scanner you can get better results. Always arrange the scene to have the best conditions for scan first and only then manipulate the settings of the scanner.

Distance

Closer objects have a better spatial resolution and generally less noise.

Material albedo (reflectivity)

A material with higher albedo provides a better signal-to-noise ratio.

Strong ambient light

Indoor ambient light generally does not influence the scan. However, very strong light such as direct sun might be a problem. This occurs especially when scanning outdoors. Try to remove all sun illumination e.g. by shadowing the window, or by moving into a different place.

Reflections

Generally, non-glossy, matte materials are scanned without problem. Even soft-gloss objects have a nearly optimal scan. However, any specular reflections might influence the scan quality since the projected light is reflected out of the sight of the camera (in which case that part has a poor quality), or when reflected into other parts of the scene, reflected light interferes with scanning (in which case the part illuminated by reflection has artifacts). Especially metal with high-gloss finish (mirror-like) is problematic.

As a rule of thumb: Take a flat piece of the material and try to look at it as it be a mirror. If you are able to recognize a shape of your head as reflected by the material, the material is glossy. Depending on the scene, some parts might be not scanned optimally.

When scanning glossy objects, find a position where light coming from the projection unit does not illuminate other objects on the scene. To further increase change of optimal scan while scanning glossy materials, use the “Scan glossy / Scan on sunlight” setting. Using this setting will increase the scanning time.

Transparent objects

It is not possible to scan transparent materials such as glass, ice or water . Remove such materials from the scene to avoid artifacts. A thin layer of plastic wrap would still allow the wrapped object to be scanned with the risk of greater noise. It might also increase the glossiness of the object (see previous paragraph). Scanning through a window is possible as long as the window does not cause reflection — the angle between projector unit and window should be close to a right angle.

Translucent objects

It is possible to scan translucent objects to some extent. Scattering of the light inside the material might cause the object surface to be scanned with a lower precision. For materials of a high degree of translucency the same applies as for the transparent objects.