we introduce RoMA
the robotic modeling assistant
a system that allows users
to design 3d digital models in Augmented Reality
while a robotic 3d printer fabricates the design
at the same time, in the same space
With RoMA, users can integrate physical constraints early in the design process
place physical references on top of partial prints to support further designs
and design and print directly onto existing objects
RoMA's hardware consists of three
components
the user's Augmented Reality headset with accompanying controllers
the shared rotating platform
and the robotic 3d printer
the user designed 3D
primitives and Augmented Reality
at the front half of the platform
meanwhile the robotic 3d printer built a wireframe representation
of the design at the back
RoMA features a proxemics handshake
mechanism
if the user touches the platform
the robotic arm retreats and
parts away from the print
if the user leaves the printing area the robot takes control of the platform to finish the print
we now demonstrate RoMA's
interactions by designing a teapot from scratch
using the width of his hand as a
design reference the user creates a
teapot body in augmented reality
he then refines the shape of the teapot body
with spline control points
after confirmation, the robot begins printing the wireframe structure of the model
the Augmented Reality rendering  matches the printed wireframe closely
following our
proxemic mechanism
printing occurs only at the back of the platform
in RoMA the
designer and robot works simultaneously
as the robot prints at the back half of
the platform the user can design the
spouts at the front
before committing this spout to print
the user refines his design with spline control points
now the designer wants to
create a teapot handle opposite the spout
the designer touches the printing
platform to rotate the teapot
the robot retreats and parks automatically
the designer freely rotates the platform
once the designer releases the platform
the robot will resume printing at the back
to design the handle the user first
chooses a cross-section
based on the width of his finger
the designer wants the handle to fit
snugly around his finger
so he rests his finger against the partially printed teapot
and builds a handled directly around his finger for a precise fit
the designer checks to make sure that he
is satisfied with his design
and then steps away from the printer
sensing that the designer has left the
robot takes full control of the platform
the robot can now rotate the platform at will
to finish printing the entire teapot
stray strands from the motion of
the robot are easily trimmed away for a polished result
RoMA makes it easy to
design functional extensions onto existing objects
in this example the
designer builds a stand
for a model fighter jet
the designer clamps a
fighter jet model onto the platform and
quickly scans the fuselage with the AR
controller
now the designer can design directly on to the fighter jet model
RoMA is accurate enough to print onto
the existing physical object
With printing complete the stand is
ready for immediate evaluation
