photogrammetry is the process of creating 3d models with textures of
existing objects or spaces shooting many overlapping photos from different angles
we make has a fully automatic 3d reconstruction engine
all you need to do is upload all your photos and it does everything to create
a textured model for you to inform shooting better photos for
photogrammetry it's important to understand some of the basics of how the
photogrammetry process works behind the scenes photogrammetry relies on feature
detection
first the software will go through all of your images and detect common points
between any pair of overlapping photos many thousands of features will be
detected in each pair with significant overlap using the 2d features in a pair
of photos simultaneously
it is possible to solve for the camera and feature . location in 3d space
remake simultaneously solves all pairs creating accurate camera locations and
surface points for all the photos submitted then it reconstructs the
geometry and creates textures using the positions of the cameras for feature
matching to work
just make sure that nothing moves in your scene while you're shooting
also make sure to get plenty of overlap between your photos some objects will
not work with photogrammetry transparent translucent shiny heavily specular or
reflective objects all look different when viewed from different angles and
can cause the matching algorithms to fail
one solution for these types of objects is to use a matte chalk spray paint you
can find in most art stores
this pain is temporary and it can easily be wiped off after your shoot
in this example the designer wanted to capture a glass skull to test out new
design ideas for different finishes
let's take a look at some of the common shooting strategies
first let's look at the high end technique of photo boots
photo booths have hundreds of cameras and a spherical or cylindrical set up
around your object
often they have flat diffuse lighting built in as well
they are the perfect solution for shooting moving objects like people
since all cameras fire at the same time of course not everyone is going to have
access to a large studio and hundreds of cameras to build a photo booth of their
own but it's a good idea to keep this technique in mind as you can try to
replicate the camera angles and the flat even lighting when using a single camera
the most common and accessible technique is moving your camera around your
subject for high-quality results when shooting objects
the basic idea is to go around the object shooting full loops of photos in
increments of 5 to 15 degrees
if the object is complex and has lots of occlusions shoot in smaller increments
make several loops at different heights
then add extra photos to fill in any heavily occluded areas at the end any
surface on your object must be visible in at least two or more photos to be
reconstructed in 3d
when shooting your photos try to fill as much of the frame as possible with the
object for larger objects or to get higher resolution textures at the end
you can move in closer to your object and shoot and overlapping rose
just make sure to get plenty of overlap between your rose
a good rule of thumb is forty percent overlap
the next shooting strategy is flying a camera on a drone or UAV this technique
is essentially the same as shooting an object on the ground only all rules of
thumb are applied at a larger scale
keep in mind that although consumer-level drone cameras with
fisheye lenses will work a light mirrorless DSLR will give a huge leap in
the 3d reconstruction quality
the next technique is automated turntables a turntable spend your object
and set increments and triggers a stationary camera
the advantage of a turntable is you can move your object to shoot all sides just
capturing the entire object for a turntable to work properly follow these
guidelines use a perfectly flat background so no stationary features are
detected in the background use a soft light from the direction of the camera
such as an LED ring light frame your photos so any clamping mechanisms are
cropped out to shoot this intricate quadcopter frame
Rose were shot every 45 degrees for the top and bottom of the frame
another option to improve the results with the turntable is to cross polarize
your light
simply add a linear polarizing film to your light and a circular polarizer to
your lens
this will remove most specular highlights to shoot this old kitchen
grinder notice that we aligned several rows to see inside the holes on the top
this enabled us to capture the entire inside of the grinder
ok
the final technique is moving your object manually
the idea with this technique is to make a curve solid background with no
features and manually move your object like the turntable this technique
captures all sides of your object
it also relies on a soft light source from the direction of the camera and
absolutely no features in the background
this is Dennis Martin with autodesk thanks for watching