Graphics Reference
In-Depth Information
Plan of attack
Before you start a capture project, plan
out the order in which you will take your
photos. It is also important to decide on
a focal length. If possible, position the
object that you want to Catch on a table
that you can move around easily and re-
main equidistant from the object at all
angles. Planning out how you will ap-
proach your subject is the key to success
when using 123D Catch.
Figure 6-5.
Use a contrasting background
Mark your territory
Consider using some sort of marking
system when your subject lacks discern-
ible features or is highly symmetrical.
123D Catch has trouble with symmetri-
cal objects, and markers will help the
application to register different sides of
the object. You will need four points for
registration between any one image and
two other images in the collection. Con-
sider placing high-contrast tape or
sticky notes on a large object. Place
enough markers so that at least four are
always visible from any of the positions
you plan to shoot from.
What kind of camera?
Point-and-shoot cameras, like those in a
regular digital camera, phone camera, or
the camera in an iPad of 3 megapixels or
higher will work well. We have been get-
ting great Catches using an iPhone 4S.
Watch the Autodesk 123D Catch tutorials
Additional tips on using the 123D Catch
software are available here:
http://www.
Taking Photos with 123D Catch
Your first step after planning out your project
is to methodically take pictures of the object
you want to Catch. Here are some tips:
Provide enough information
You will need to provide enough infor-
mation with your pictures for the recon-
struction software to create a model.
Rotate around your object, capturing a
frame every 5-10 degrees (
Figure 6-6
).
The goal is to get least 50% overlap be-
tween images. Move the camera at reg-
ular intervals and in a predictable pat-
tern (from left to right and from top to
bottom). Make sure each point in your
object is appearing in at least four shots.
When your photos do not have enough
information, your scan may have a solid
mass where there should be empty
Utilize background objects
When possible, utilize background ob-
jects around the object you are captur-
ing. This will help the software parse
depth. 123D Catch does not like a blank
wall background with flat paint. Do not
attempt to Catch objects on a flat col-
ored surface, like a white tablecloth. You
will get better results by using a back-
ground with patterns (
Figure 6-5
) that
help the 123D Catch software clearly dif-
ferentiate between the object you are
attempting to capture and the surface it
is resting on.
