we have built a sensor platform for
mobile devices the user's vision to
track motion recognized spaces and scan
the surroundings in 3d my name is
Nikolai and in this episode we will talk
about the deaf person concepts and tools
available for you to get started with
the 3d deaf Center you can scan the
space that surrounds you and use the
data to build models of your reality if
you need to fit a new TV on your wall or
place a virtual castle on the floor or
see how much ice cream you can fit in
that freezer you may want to continue
watching deaf perception can create
static models of the surroundings as you
scan them if you combine deaf perception
with motion tracking you get the power
to have virtual objects coexist with
physical objects right in front of you
this can be used to detect surfaces
obstacles or shapes of objects let's say
we wanted to simulate a gecko walking on
the ceiling we would use depth
perception to detect the surface of the
ceiling and use motion tracking to
follow the Gecko around the house you
won't need to know all the details of
how depth sensors work but it's helpful
to have a general understanding to make
the best use of them
there are several technologies available
which we will mention three major ones
first we have structured light systems
they send out an infrared pattern to
illuminate the contours of the
environment the device then measures the
size of the dots the larger the dot gets
the further away it is second time of
flight systems use specialized sensors
to measure depth based on the time it
takes to transmit an infrared beam and
capture its reflection at short
distances it only takes the light a few
nanoseconds a few billions of a second
to travel back and forth third there are
stereo systems which captures the scene
with two cameras that are short distance
apart
and infer depth from using triangulation
does that sound complicated well this is
very much how human eyes work two eyes
or cameras for that matter that are able
to see the same scene but from slightly
different angles enables the viewer to
gain a perception of depth using
trigonometry the inference based depth
centers such that structured light or
time-of-flight based systems have the
benefit of working particularly well
indoors in low-light and where there are
isn't any textures on the walls on the
other hand infrared light is less
reliable in direct sunlight and on very
dark surfaces which tend to absorb
infrared light because it reduces the
amount of depth data you will acquire
the centers in project tango are
currently optimized to scan room size
and static environments which makes it
well suited for detecting surfaces large
objects like walls doors tables and
chairs other requirements to bear in
mind as you design your program is the
need for resolution range and speed
resolution determines how much detail
you can capture range how close afar you
can be to an object and speed is how
fast you can capture the motion project
tango returns depth data as a point out
it is the raw representation of what the
sensor detects you can use project tango
Explorer to see what data looks like in
the point cloud mode each of the
displays dots is associated with a
position and a distance to the device if
as you move around Explorer applies
motion tracking to combine multiple
point clouds into one the raw data is
great for calculating floor height
distances to nearby objects or to find
surfaces if you instead wants to create
complete 3d models or meshes you can use
an app like project tango constructor
let's have a look at how that works as
you scan an area with constructor the
app combines depth data with colored
images from the camera while you can
watch the 3d model of the surroundings
as it's being built when you're done
scanning the area this constructor can
export a file of the generated 3d models
to the SD card from there the file can
imported by other apps or games if you
want to test drive a micro version of
the Mars rover in the sandbox we could
use constructor to create 3d models of
the hills and valleys in the sand export
the data and then build an app that uses
the exported data as the surface for the
rover project tango is all about
connecting the virtual with the physical
experience and the depth sensor
literally brings fit the physical world
into the virtual world so you can build
virtual biology experiments or Mars
rover simulators visit our Google+
community and join us on our journey we
are excited to see what you will build
with project tango
you