Nehab, D.
2006--.
Abstract:
Range scanning, manual 3D editing, and other modeling
approaches can provide information about the geometry of
surfaces in the form of either 3D positions (e.g., triangle
meshes or range images) or orientations (normal maps or bump
maps). This software implements an algorithm that combines these two
kinds of estimates to produce a new surface that
approximates both. Our formulation is linear, allowing it
to operate efficiently on complex meshes commonly used in
graphics. It also treats high- and low-frequency components
separately, allowing it to optimally combine outputs from
data sources such as stereo triangulation and photometric
stereo, which have different error-vs.-frequency
characteristics. Therefore, the algorithm is capable of
both recovering high-frequency details and avoiding
low-frequency bias, producing surfaces that are more widely
applicable than position or orientation data alone.
Links:
home page [html]
Nehab, D.
1999--.
Abstract:
LuaSocket is a Lua
extension library that is composed by two parts: a C core
that provides support for the TCP and UDP transport layers,
and a set of Lua modules that add support for functionality
commonly needed by applications that deal with the Internet.
The core support has been implemented so that it is both
efficient and simple to use. The core can be used by any
Lua application once it has been properly initialized by the
interpreter running the Lua application. The code has been
tested and runs well on several Windows and Unix platforms.
Links:
home page [html]
Nehab, D.
2003--.
Abstract:
RPly is a library that lets applications read and write PLY
links. The PLY file format is widely used to store
geometric information, such as 3D models, but is general
enough to be useful for other purposes. There are other
libraries out there, of course, but I decided to write my
own. I tried to write it in such a way that in other
incarnations I won't have to do it again. Everything that
made me unhappy about the existing libraries was eliminated
from RPly.
RPly is easy to use, well documented, small, free,
open-source, ANSI C, efficient, well tested and I will keep
supporting it for a while
Links:
home page [html]
(or Functional programming for the rest of us)
Nehab, D.
2004.
Lua Technical Note 012, LTN012
also published in Lua Gems
|
Abstract:
Certain operations can be implemented in the form of
filters. A filter is a function that processes data received
in consecutive function calls, returning partial results
chunk by chunk. Examples of operations that can be
implemented as filters include the end-of-line normalization
for text, Base64 and Quoted-Printable transfer content
encodings, the breaking of text into lines, SMTP byte
stuffing, and there are many others. Filters become even
more powerful when we allow them to be chained together to
create composite filters. Filters can be seen as middle
nodes in a chain of data transformations. Sources an sinks
are the corresponding end points of these chains. A source
is a function that produces data, chunk by chunk, and a sink
is a function that takes data, chunk by chunk. In this
technical note, we define an elegant interface for filters,
sources, sinks and chaining. We evolve our interface
progressively, until we reach a high degree of generality.
We discuss difficulties that arise during the implementation
of this interface and we provide solutions and examples.
Links:
Wiki page [html]
(or How to get rid of all those if statements)
Nehab, D.
2004.
Lua Technical Note 013, LTN013
Abstract:
This little LTN describes a simple exception scheme that
greatly simplifies error checking in Lua programs. All the
needed functionality ships standard with Lua, but is hidden
between the assert and pcall functions. To
make it more evident, we stick to a convenient standard (you
probably already use anyways) for Lua function return
values, and define two very simple helper functions (either
in C or in Lua itself).
Links:
Wiki page [html]
