Graphics Reference
In-Depth Information
to form faces (flat surfaces enclosed by
edges) that describe the shape of a 3D ob-
ject. STL files are comprised of these trian-
gular meshes.
Kinect vs. Asus Xtion
As soon as the community cracked open the
Kinect and made it do things it wasn't intended
to do, 3D scanning was one of the first items
on the list. As wonderful and disruptive as the
Kinect was, it wasn't the only device of its kind.
In fact, other folks brought the exact same
technology to market. Scanning with the Kin-
ect is powered by hardware developed by an
Israeli company, PrimeSense. PrimeSense re-
leased a software development kit (SDK)
called OpenNI (Open Natural Interaction) that
some people, such as the folks behind Recon-
structMe (PROFACTOR GmbH), have used to
develop awesome software tools for Kinect.
And the great thing about this is that their
software can be made to work with other hard-
ware that uses the PrimeSense technology.
123D Catch works by analyzing a group
(twenty to forty) of images of an object taken
from different angles. (The analysis for 123D
Catch is performed in Autodesk's cloud-
based systems.) By performing image
analysis on the photos, 123D Catch is able to
isolate an object in the photos and create a
3D mesh from the collection of photos.
One such piece of hardware is the ASUS Xtion
($160), which has some advantages over the
Kinect:
1. It is much smaller (about half the size).
2. It's lighter (half a pound).
3. It doesn't require a separate power sup-
ply (it can be powered over the USB
connection).
The Xtion has some disadvantages, though:
Figure 6-2.
A point cloud
1. It's more expensive.
2. It does not work with all software writ-
ten for the Kinect.
3. It doesn't have a software-controlled
motor (the Kinect has one you can use
for moving the camera around).
Still, if you're looking for a portable depth cam-
era for 3D scanning, the Xtion is well worth
considering.
(or vertices), it groups each vertex with
edges (straight line segments) that combine
