Yes, your models can be sent
to a 3D printer and printed in 3D, even in colour! You can
even print in stainless steel or glass! A model a few cm
tall might cost a few tens of Euros. Check out www.shapeways.com .
Here is an example of an object printed on a 3D
printer. It's Suzanne, Blender's mascot. I had to spend a couple of
hours modifying the monkey that is included with Blender before it
was ready for printing. It's about 12 cm wide and cost about 20
Euros to print at Shapeways. I hope you like it (my cat did).
Make no mistake: preparing a model
for printing in 3D is much more difficult than making a
model that can be viewed on a computer screen for the model for
printing has to be a closed 3D surface - our model house with doors
and windows would not print, for example, for its walls were
surfaces that had zero thickness - such walls cannot be printed
since they have no volume. A closed 3D surface can be said to be
'watertight' but there are additional requirements that are even
harder to understand: the model must be 'manifest' (every edge must
be connected to exactly two faces) and all the normals must point
out of the the 3D surface. The Shapeways site gives lots of help
in meeting these requirements, but expect to spend hours modifying
your model if you want it to be printed in 3D.
A good trick for keeping the cost
down is to make the model hollow since you only pay for the volume
of material actually printed, but hollowing out your model requires
even more work. The 'solidify' modifier is very useful for producing
a thin shell. Here is a hollowed-out model of Suzanne that I made
based on the built-in Blender monkey mesh (in the end this one was
unprintable for its smooth surface consists of nearly half a million
faces and I wasn't able to identify and fix the few faces that
caused problems).
Note the hole that I made in
Suzanne's neck so that unused plastic powder can be removed from
inside the model after it is printed.
Watch this video to learn more
about how 3D printing works:
3D Scanning
Believe it or not, you can scan objects in 3D
at very low cost. This is what you need:
A special 'line laser' which projects a
line rather than a dot of light and which can be bought from the
above site for about 30 Euros. You might even be able to
improvise a line laser by shining a standard laser pointer
through the stem of a wine glass
A printout of a special calibration pattern
which is included with the software
A Windows PC
How does scanning with DAVID work?
1.
Set up background and camera
2. Calibrate your camera with one click
3. Start scanning by sweeping the laser line over the object
4. Gaze at the 3D window and export your result in .OBJ format.
Each scan produces a 3D mesh of one side of the
scanned object. To create a 3D mesh of the the whole object you must make
several scans and join then together with software.
1.
Set up background and camera
