Advances in computing power combined with interactive modeling
software, which lets users create images as queries for searches, have made 3Dsearch technology
used involves the following steps
" Search process
" Search result
True 3D search systems offer two principal ways to formulate a query: Users can
select objects from a catalog of images based on product groupings, such as gears
or sofas; or they can utilize a drawing program to create a picture of the object
they are looking for. or example, Princeton's 3D search engine uses an application
to let users draw a 2D or b of the object they want to find.
The above picture shows
the query interface of a 3D search system.
3D-search system uses algorithms to convert the selected or drawn image-based
query into a mathematical model that describes the features of the object being
sought. This converts drawings and objects into a form that computers can work
with. The search system then compares the mathematical description of the drawn
or selected object to those of 3D objects stored in a database, looking for similarities
in the described features.
The key to the way computer programs look for 3D objects is the voxel (volume
pixel). A voxel is a set of graphical data-such as position, color, and density-that
defines the smallest cubeshaped building block of a 3D image. Computers can display
3D images only in two dimensions. To do this, 3D rendering software takes an object
and slices it into 2D cross sections. The cross sections consist of pixels (picture
elements), which are single points in a 2D image. To render the 3D image on a
2D screen, the computer determines how to display the 2D cross sections stacked
on top of each other, using the applicable interpixel and interslice distances
to position them properly. The computer interpolates data to fill in interslice
gaps and create a solid image.