ShapeMetriX3D
is an innovative System to acquire surfaces with three-dimensional
images.
For data acquisitiona standard
digital camera is used which is calibrated by
software from 3G Software & Measurement. With the
calibrated camera the designated area is imaged from two
different angles. Only a range pole must be placed in
the imaging are in beforehand (see Figure 1) – the
time need for the complete data acquisition process
(establishment of range pole, taking two pictures) is
about 1 minute.
Common applications
are within tunnelling, mining, and for different kind
of documentation. An important characteristic of ShapeMetriX3D
is that a 3D assessment software component is included.
Figure
1: Stereoscopic image pair of a tunnel face. Note
the range pole
After data acquisition
on site the images are transferred on a standard PC and
processed into a three-dimensional image using the SMX
Reconstructor software. The used principle is
stereo-photogrammetry with certain extensions, such as
having no need for reference markers to determine the
relative orientation of the images among each other.
Fundamentally the used principle is scalable which means
that surface of various sizes can be images and processed
by reconstructing the photos to a 3D image. Though one
requirements is that the surface must show certain (irregular)
structure (texture).
The result is a 3D image
that represents the shape of the recorded surface (refer
to the name of the system). From the 3D image measurements
can be taken and assessments performed using the provided
3D software.
Figure
2: 3D image of a tunnel face.
This kind of 3D imaging
in non geo-referenced in general, i.e. the results do
not have a relationship to the object-ordinate system
though an approximate orientation using construction elements
(e.g. arcs) visible in the images is possible.
Is geo-referencing required then the JointMetriX3D
system can be used or at least three points with known
co-ordinates in the object co-ordinate system are visible.
Main distinctions
to conventional documentation:
Rock
mass conditions are represented objectively
and reproducible
There are no access problems
and no pressure of time for the assessment
Metric measurements (lengths,
distances, areas) are possible
Measurement of orientations
are enabled (dip and dip direction)
Derived properties,
such as spacing can be determined directly
Main distinctions
to conventional surveying:
A 3D image is not an (abstract) bunch of
3D surface measurements but a real image with
hundreds of thousands assigned measurements
behind.
No special skills for data acquisition required
(use of a digital camera)
Main
benefits at a glance:
Mobile contact-free rock wall measurement
without requiring surveying skills or instrumentation
Simple application (taking pictures)
Cost-efficient
Reproducible rock mass conditions
Cost reduction for excavation or exploitation
works
System is not only a measuring device but
provides also a software tool for doing assessments
