How many input
meshes can be in one file, and how many triangles
can your software handle?
A maximum of 32K individual meshes and 4 billion (2^32)
triangles are allowed. However, the amount of memory
that a mesh needs is the practical limit: The input
mesh must be copied prior to compression to preserve
it; Two 7 million triangle meshes use approximately
2GB of virtual memory. (These numbers will vary depending
on the presence of pre-computed normals, the number
of holes, the number of material groups, etc.)
How much RAM
do I need?
The amount of RAM is fairly linear with the number
of triangles; A rule of thumb is 1K of memory per
triangle, e.g., 128K triangles use 128MB RAM.
How long does
it take to decompress a mesh?
To give you an idea of how fast the decompression
works here are some numbers.
128K faces: 1.8 sec.
512K faces:
6.7 sec.
2M faces: 32 sec.
System: P6 800 MHZ, 2048MB RAM
Can you handle
textures?
Our software retains material properties for triangles,
per vertex color and textures for environment mapping.
Texture coordinates are compressed too with respect
to the input level of accuracy. Bitmap textures are
converted to jpg and then embedded in the compressed
file. Per vertex color and texture together are not
supported currently. Lossy compression (polygon reduction)
does not move vertices, so texture mapping coordinates
are not disturbed.
Why does turning
off video acceleration improve performance on some
files?
Turning off video acceleration seems to help because
the software display lists are usually much smaller
than most video card OpenGL driver display lists.
One reference point: 1GB RAM, 64MB video card can
rotate up to 300K triangles without problem; 500K
is very slow.
Why can't
I export to STL, OBJ, PLY, etc. after I have opened
a compressed file?
This is disabled in order to provide a level of security
for your data. However it is possible to enable this
capability thru the SDK. There is a flag in the .3dc
file that indicates if export is allowed.
Does the architecture
of this software allow it to be easily integrated
into another program, such as a database/data processing
application?
Yes, we have an SDK which is very easy to integrate
into your product. You can add your own interface
on the server side, as well as on the client/viewer
side.
The program
didn't crash, but I only got 60 percent ratios, and
nothing displayed in the "Compressed" window.
When opening in a Web page after saving as .3dc, only
one triangle plane appeared.
Although we validate and repair meshes, there are
some extremely flawed meshes that cannot be fixed
automatically. If the mesh is nonmanifold or has topology
problems, the mesh cannot be compressed.
Does your
software provide control over the number of triangles?
Our software does provide control over the number
of triangles. You can access this by going to Tools->Polygon
Reduction. Click on the Percent radio button to enable
the input for the percent of triangles to which you
would like to reduce. Afterwards, you can export to
a variety of formats.
