| Q&A |
 Christof
Reinhart
CEO Volume Graphics GmbH
05/03/04 |
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About
this illustration :
It is rendered by VGLR 3.2 in voxel graphics. No polygonal
model is used to generate this image. The surface structures
you see are real 3D structures no texture or bump mapping!
The object you see is an industrial computer tomography
scan of an engine head of a BMW build in 1937. The data
set consist of 1036 slice images each with 1024x1024 pixels
at 2 byte per pixel. So all together we have slightly
more than 2GB of data in the original voxel
data set you see in this image. In the lower left area
a section was cut away from the data set. The rendering
was done with full shading (ambient, diffuse and specular)
with two light sources (one frontal parallel and one
spot light) and shadowing. |
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| Q1 |
A
brief presentation of Volume Graphics GmbH. |
| A1 |
Volume
Graphics develops and markets 3D graphics technologies and
application software for multidimensional image processing
and analysis. The company's history started more than 10 years
ago when the founders developed the world wide first real-time
volume rendering hardware system. With the enhancements in
standard PC hardware the company focused on software solutions.
Today Volume Graphics provides 3D voxel graphics technology
to the healthcare industry as well as application software
to the industrial - mainly in high tech branches like aerospace
and automobile industry - and scientific market. Volume Graphics'
VGStudio MAX software has become the standard software tool
for industrial CT applications and is distributed world wide. |
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| Q2 |
What
are the benefits of using Voxel geometry rather than meshes
? |
| A2 |
To
answer this question we have to talk about two aspects:
a) The application aspect:
In medical applications or in industrial quality control you
have to work with volumetric data representations giving you
information not only of an objects surface but also of the
interior structure of the tissues and/or materials. It is
obvious that voxel data has an inherent advantage over polygonal
representations in this case.
b) The technological aspect:
In applications where you deal with "real world"
data, e.g. data generated by a 3D imaging device like computer
tomography, you are able to deal with a much higher level
of detail at the same time at much higher rendering performance
than any polygonal representation could achieve. E.g. an object
scanned to a voxel data set with 1024x1024x1024 voxels = 1GVoxel
can be rendered with interactive performance on any Pentium
4 CPU. The same object represented by a polygonal mesh that
still does not reach level detail of the voxel object, easily
exceeds several ten million triangles. The rendering performance
for such a huge mesh on today's most powerful graphics boards
is much lower that our voxel graphics technology. Another
important aspect is that the voxel data base allows us to
generate more physical and therefore more realistic models
of the world we see around us. Our real world is solid not
hollow. The interaction of a ray of light with an object's
surface is typically not an interaction in a single point
but in a whole transition layer. When we talk about photorealistic
rendering I'm sure that voxel graphics will play a bigger
and bigger role in future. As we all know voxel graphics can
be found today where the most demanding visualization tasks
have to be solved, e.g. rendering of special effects like
explosions, fire, clouds, fur. Today voxel graphics is less
popular in the animation market only because of missing software
tools and because of the computing power needed. Our VGLR
graphics technology already solves the later aspect. We are
able to handle large data sets with highest levels of details
at high performance. However in our days the most relevant
question is what the needs of different applications are.
Both worlds, the polygonal and the voxel world, have their
advantages, polygons for designed "artificial" objects
and voxels for "real world", scanned objects. With
the availability of modern voxel graphics technologies like
VGLR we will see more voxel graphics in future in many application
fields. |
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| Q3 |
What
are the main applications of Voxel graphics? |
| A3 |
The
major markets for voxel graphics today are the "classical"
healthcare market, medical content creation for education, entertainment
and advertising.
The industrial market evolves more and more since quality control
with 3D imaging devices has become an important tool. The visualization
of seismic data in the oil and gas industry as well as all the
scientific disciplines where voxel data is scanned or computed
are additional markets for voxel graphics. |
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| Q4 |
Can
VG Studio Max generate 3D Voxels from point clouds datas (3D
scanner)? |
| A4 |
Not
yet. It might be able in near future if the market requests
it. |
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| Q5 |
What
are the features of VGStudio Max in the field of visualisation
and collaborate work? |
| A5 |
VGStudio
MAX is capable to visualize nearly any kind of voxel data. The
range reaches from greyscale to true colour, from 8 Bit integer
to 32 Bit floating-point data. Objects can be rendered with
different rendering algorithms, e.g. volume raytracer with full
shading support, maximum projection methods and many more. Opacity
and colour mapping is also possible as well as it offers all
kind of clipping support. A simple but easy to use animation
rendering tool is a standard feature of VGStudio MAX. This tool
is used by scientists or engineers to present their analysis
results as well as by professionals in the animation industry.
We haven't developed solutions for collaborate work yet. However
this is not because of any technical limitations of voxel graphics.
Most users in all the major applications where VGStudio MAX
is used don't ask for a collaborate work environment. VGStudio
MAX is typically used by a single engineer or a scientist who
analyzes, visualizes or animates his data. The analysis results
of course are distributed but people typically don't work on
one data set at the time. |
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| Q6 |
Is
it possible to display both Voxel and meshes in the same 3D
scene? |
| A6 |
Yes
our VGLR graphics technology was developed with the idea of
a seamlessly OpenGL integration in mind. VGLR allows to integrate
polygonal objects into voxel scenes or vice versa. |
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| Q7 |
VG
studio Max creates presentations for industrie/science ; but
can it displays realistic models too (with "texture-like"
models)? |
| A7 |
Today
VGStudio MAX is still based on our former VGLR 2.x technology.
We will soon show the next generation VGLR 3.x in our application
software. The VGLR 3.x renderer probably creates more realistic
images form scanned objects than any of the most advance polygonal
renderes from designed objects. Images rendered from true colour
data sets like the famous visible human data set have proven
this. |
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| Q8 |
Is
it possible to use your tools combining with Virtual Reality
displays and interfaces? |
| A8 |
Yes,
VGLR 3.x can be used to develop such solutions just in the same
extend as OpenGL. Our application software already supports
VR devices like auto-stereoscopic or head-mounted displays. |
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| Q9 |
Can
Voxel display take advantage of 3D hardware capabilities (OpenGL/DirectX)? |
| A9 |
In
the past the graphics hardware was not powerful and flexible
enough. Modern graphics hardware comes with larger and larger
on board memory. In addition the graphics chipsets include more
and more freely programmable units. Therefore we can use today's
graphics boards with up to 512 MB onboard memory to visualize
small and medium voxel data sets more and more efficient. We
have sown already at SIGGRAPH 2002 a first prototype of a volume
renderer with shading support implemented completely on a 3DLabs
Wildcat VP board. Our VGLR technology already takes advantage
of today's most advanced graphics hardware and its future proofed
architecture allows us to integrate any upcoming graphics hardware
into the VGLR framework. |
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| Q10 |
What
kind of performances benefits can users expect from using your
product with a 64 bit processors workstation (VG Studio is one
of the first 3D software that take advantage of both I64 and
AMD64 instructions) ? |
| A10 |
The
performance of the software renderer in VGLR depend mainly on
the pure computing power of the CPU. There is no direct advantage
in terms of performance when using 64 Bit CPUs as long as they
don't provide more computing power that today's 32 Bit CPUs.
However the main advantage of 64 Bit platforms is their capability
to deal with data sets of several GB in size. Our VGLR technology
was able to deal with data sets much larger than 1GB already
on 32 Bit platforms. With 64 Bit platforms we are now only limited
by the available system memory and the available computing power
and no longer by a 32 Bit address space.
Our customers today have already to deal with 8GB data sets
in their all day work. They handle these data sets with Intel
Itanium or AMD Opteron systems and specialised software we developed
for these platforms. Larger data set provide a higher level
of detail. This allows our customers, e.g. to see even smaller
defects or lesions. In the same ways 64 Bit platforms enable
us to render even more photo realistic images. |
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| Q11 |
Voxel
data are often considered to be difficult to manipulate and
animate, is it true? |
| A11 |
Well
this opinion was caused by the fact that there was no application
software available for these tasks. Some years ago there was
no real market for a software tool that manipulates or animates
voxel data. Voxel data has been something exotic. This has changed.
We now have plenty of examples where we can see that voxel data
has become a not only a common but also a "famous"
kind of data. Probably the best example for a famous voxel data
set is the NIH Visible Human data set. Images rendered and models
generated from this data set have been used all over the world
for education, advertising and entertainment. When we started
Volume Graphics back in 1997 we had to explain everybody what
voxel data is. We don't have to explain this anymore since several
years now. With the availability of more powerful hardware,
people generated more voxel data and companies like Volume Graphics
now offer all kind of: Solutions about Voxels. |
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| Q12 |
Can Voxel datas be compressed for fast data transfert (mail,
internet) ? Do you plan to develop a web player ? |
| A12 |
There
is no difference between 3D voxel data and 2D pixel data except
the additional dimension. A pixmap is just a voxel data set
with only one slice image. The same methods used for 2D image
data can be used to compress 3D voxel data. The simplest example
is JPEG compression. However we have the third dimension within
a voxel data set and therefore we have to transfer more data
of course. However with the continuous increase of internet
bandwidth it is no principle problem anymore to transfer small
and medium voxel data sets via the internet. We already exchange
voxel data set with our customers via internet in our all day
work.
There was no market for a web player in the past. We have some
requests and some ideas how our customers might take advantage
of web-based data exchange. With the ongoing technological progress
in networking technologies we might see voxel graphics based
web-tools a tool in future |
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