3d Daten konvertieren?
Hallo Jane,
dank für die Nachfrage. Ich habe mich anläßlich dieser Sache aufwendig kundig gemacht. Die sachkundigste (und leider auch unangenehmste) Antwort dazu habe ich von Polytrans bekommen. Auf Wunsch leite ich sie gern weiter.
Letztendlich mußte ich das Problem anders lösen, insofern gibt es das Problem jetzt nicht mehr 😉
Nuuun kommt’s erschöpfend, im besten Sinne des Wortes 😉
Hier beantwortet Robert von Okino meine Frage:
Hello Dietmar,
Do you offer an individual service of converting?
Its a molded whiskey glass, made with cinema 4d (about 4000 points), needed to be converted for 3d printing to STP or another solid.
Thanks for asking. No one ever converts from Cinema-4D to STEP, CAD, ACIS or
any CAD file format – it is simply technically impossible to do. I receive
this same question 3 or more times per day since 1996. It’s always been the
#1 epidemic question which I receive amongst all. You can’t do this because
STEP+CAD is based on pure NURBS geometry whereas Cinema-4D is one of the
world’s simplest polygonal modellers. You can’t turn meshes into a
proper solids model as you expect. It is like turning water back into an ice
sculpture.
It’s become an even more rampant problem since the SketchUp software became
popular back in 2010, as there’s 25 million people all trying to use SketchUp
as a MCAD modeller (which it is not). Hence, even though your question relates
to other concerns, I do explain this problem in a slightly deeper manner
online here:
www.okino.com/conv/exp_sketchup.htm#reconstruction
At most, you’ll need one of these interactive surface approximation programs.
They allow you to interactively re-surface a mesh model with NURBS
equivalents, after which you can then attempt to stitch the NURBS back into a
BREP solid. You do need a proper program to re-engineer the mesh data into
proper NURBS, and then turn the NURBS into solids.
Now, no one ends up doing this since the average costs are in the $5k range,
and you still need to spend many hours doing the reverse engineering yourself.
In the end, you always need to reverse engineer the mesh by resurfacing it.
Unfortunately there are unlimited number of YouTube videos, world-wide forum
postings and $99 plug-ins from India which just pull the wool over the eyes of
the unsuspecting.
1) Raindrop (RapidForm) „XOR Redesign“
Mesh to NURBS (IGES and STEP) automatic resurfacing software
www.rapidform.com/products/xor/overview
Requires that a user-defined curve network be put down over the
high quality input mesh (as does all solutions below) in order to
begin the reverse engineering process.
Price range of US$10k to US$30k
2) „ScanTo3D“ in SolidWorks Premium Edition
As in all mesh to NURBS reconstruction software, this will require
considerable human involvement to assign the 3D character and
sketch curves to the model before it is resurfaced.
help.solidworks.com/2015/English/…/c_Scanto3d_overview.htm
3) Raindrop Geomagic
www.geomagic.com
Product = „Geomagic Studio“, price is $20,000
„The meshes are then converted to surfaces with the AutoSurface command, which
shrinkwraps“ surfaces onto the polygon meshes. The software makes assumptions
based on the style of surfacing you select: (1) mechanical, which applies
holes, corners, and so on; or (b) organic, which emphasizes free flowing and
sharp points on shapes. You can also manually convert meshes to surfaces by
(1) identifying features, such as extrusions, planes, lofts, sketch curves,
and so on; and then (2) applying them. The surface models can be exported as
3D PDF, IGES, or STEP files.„
The Raindrop company is continually working on making the process more
automatic – from scan to CAD model without manual intervention. The goal is
still some years away, but he figures that Geomagic will be first to figure it
out. “
4) Geometry Systems – GSI Studio, mesh to NURBS surfaces
www.geometrysystems.com
GSI Studio costs approximately US$6000 for all features:
Scan data processing, mesh clean up, surfacing,
restructure mesh, color/texture processing.
GSI Surface Studio costs approximately US$3500 per seat.
It converts from mesh data to NURBS surfaces.
The process is manual. The main task, as with all similar programs
is to clean-up the mesh data: most meshes are a mess and hence
need to be cleansed prior to the manual process of reverse
engineering each small or large feature of the input dataset.
On NURBS export, it can save to IGES and Rhino files, and has
limited support for STEP.
5) headus, CySlice v3 – Subdivision Surfaces
www.headus.com.au
US$4000, floating US$4600
Imports OBJ, STL and PLY file formats.
Exports NURBS and SubDivs to IGES and OBJ.
No BREP topology info is output to IGES.
Light weight meshes are automatically converted.
Dense meshes require that the user draw patch boundaries first.
6) PolyWorks
www.innovmetric.com
Price range US$10k to US$30k per solution
7) VRmesh Reverse, US$1295.00
www.vrmesh.com/products/reverse.asp
For point cloud and triangle mesh processing.
„A complete reverse engineering workflow for users to wrap point cloud
data into accurate polygon meshes as well as NURBS surfaces.“
8) SpaceClaim, US$2500 to US$3500
www.spaceclaim.com
SpaceClaim provides reverse engineering tools for mesh data.
9) McNeel’s Rhino modeler has „helper plug-ins“ which aid in the mesh to NURBS
reconstruction process.
wiki.mcneel.com/rhino/reverseengineering
As is the norm industry wide (and little believed by many 3D users),
McNeel has rightfully also disclaimed, as we do in this email, that „No one
click miracles here. Once a 3D model is in mesh form, it’s hard to re-create a
smooth NURBS object from it. There are also a number of specialized reverse
engineering software packages to partially automate this process, they range
from moderately expensive to very expensive.“. Their own „MeshToNurb“ command
does no such 3D mesh to smooth, connected NURBS conversions as often confuses
many people on forums.
Regards,
Robert Lansdale, CTO & Product Manager
Okino Computer Graphics.
1515 Britannia Road East. Mississauga, Ontario. L4W 4K1.
Tel: 888-3D-OKINO, (905) 672-9328. www.okino.com
Jupp, Du liegst falsch,- steht bei Robert. Ich hab’s probiert, C4d > STP, und heraus kam sozusagen eine Punktewolke. (betrachtbar z.B. mit FreeCad). Und nun hätte man für jeden Punkt die Nachbarpunkte definieren müssen, um daraus Flächen zu bilden & das Ganze zu einem geschlossenen Hohlkörper umzudefinieren. Das geht einfach und schnell bei regelmäßigen Flächen, aber z.B. bei einem unregelmäßigen Relief in hoher Auflösung ist’s unendlich Arbeit. So jedenfalls verstehe ich Robert.