Re: [rp-ml] texturing on 3D data

Hello,

I have thought about this problem for a long time. In short, this is a
research problem.
Representing texturing in computer graphics via a binary image-map is a
practical response to a fundamental Level-of-Detail (L.o.D.)
<http://en.wikipedia.org/wiki/Level_of_detail> problem.

The complete solution is to support evaluation of Displacement-Mapping
<http://en.wikipedia.org/wiki/Displacement_mapping> in the R-P slicer.
Short of that, extensible, programmable rendering languages, such as
Pixar's RenderMan <https://renderman.pixar.com> can actually perform
this slicing in three-space, complete with displacement-mapping and will
produce the slices as a set of binary images.

Once upon a time, the RIKEN Institute in Japan developed a slice-wise
interface to the Z-Corp. Z406 color 3D printer. Alas, if only Z-Corp,
itself would only support such a feature, then you could certainly
evaluate displacement mapping using RenderMan as the slicer.

Sadly, without such support in software from the R-P vendors, we're
reduced to generating Copious Mesh Data
by explicitly evaluating surface displacement maps in Alias-
<http://www.alias.com>Wavefront AutoDesk (D'oh!) Maya
<http://usa.autodesk.com/adsk/servlet/index?siteID=123112&id=7635018>,
which will support this. The problem here is that displacement shaders
are typically defined on NURBS
<http://en.wikipedia.org/wiki/Nonuniform_rational_B-spline> models and
polygon meshes tessellated from NURBS models are rarely stitched,
particularly displacement shading is typically not stitched across NURBS
seams.

Take a look at this: Rhino Displacement tools
<http://forums.polyloop.net/design-modeling/12051-rhino-displacement-tools.html>
-- I haven't used Rhino <http://www.rhino3d.com/nurbs.htm> in about 10
years, but it is popular among digital sculptors
<http://www.intersculpt.org> and it is stitching-cognizant.

Evaluating displacement maps is integral to surface subdivision, however
displacement mapping in subdivision surface representation
<http://en.wikipedia.org/wiki/Subdivision_surface> is not as mature as
it is in NURBS modeling.

Good luck!

-Stewart Dickson, Visualization Reseaqrch Programmer, Illinois Simulator
Laboratory
Beckman Institute - South Facility, Room 12
http://www.ifp.uiuc.edu/~sdickson
2100 S. Goodwin Urbana, IL 61801
http://us.imdb.com/Name?Stewart+Dickson
Ph: 217-333-3923 Fax: 217-244-1827
email: sdickson@illinois.edu
http://emsh.calarts.edu/~mathart/MathArt_siteMap.html

vinod wrote:
>
> Hello RPML users
>
> Does any one know how to do the texuring on solid file. is anyone
> having experience in editing texture to STL data?
>
>
> Best Regards
> John
Received on Wed Jul 29 16:32:43 2009