Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Printed Perforated Lampshades for Continuous Projective Images   We present a technique for designing 3D-printed perforated lampshades, which
project continuous grayscale images onto the surrounding walls. Given the
geometry of the lampshade and a target grayscale image, our method computes a
distribution of tiny holes over the shell, such that the combined footprints of
the light emanating through the holes form the target image on a nearby diffuse
surface. Our objective is to approximate the continuous tones and the spatial
detail of the target image, to the extent possible within the constraints of
the fabrication process.
  To ensure structural integrity, there are lower bounds on the thickness of
the shell, the radii of the holes, and the minimal distances between adjacent
holes. Thus, the holes are realized as thin tubes distributed over the
lampshade surface. The amount of light passing through a single tube may be
controlled by the tube's radius and by its direction (tilt angle). The core of
our technique thus consists of determining a suitable configuration of the
tubes: their distribution across the relevant portion of the lampshade, as well
as the parameters (radius, tilt angle) of each tube. This is achieved by
computing a capacity-constrained Voronoi tessellation over a suitably defined
density function, and embedding a tube inside the maximal inscribed circle of
each tessellation cell. The density function for a particular target image is
derived from a series of simulated images, each corresponding to a different
uniform density tube pattern on the lampshade.

25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
18
The categories of this paper are: econ