Images and Pictures of Recent Research Projects:
Metamorphosis of freeform surfaces
This sequence of three images is a samples of a small animation created
by a metamorphosis process of freeform NURBs surfaces.
Matching of freeform curves
A matching algorithm is introduced to generate an improve metamorphosis
of freeform curves. The left shows direct convex combination while the
right shows the result of applying the matching algorithm. Note the
back and tail of the oryx.
Sculptured Surface Modeling
This
model of the B58 plane was modelled using the IRIT modeling environment and
raytraced using the rayshade
ray tracer.
Another high quality scene that was modelled using the IRIT modeling environment and
raytraced using the rayshade
ray tracer. This scene as well as the B58 above were constructed using
various freeform surface modeling tools such as ruled surface (wings
of B58), surface of revolution (the table and dishes), sweep (the
cushion and base of chairs), and skinning (the fuselage of the
B58). Similar geometries such as the engines of the B58 or the chair
were instantiated several times using rigid motion transformations.
Depth Cueing based Rendering
Rendering with depth cueing for both rendered using
rayshade
images (left) and postscript figures (right).
The postscript version also supports haloed lines. Both
examples were created using tools that are part of the IRIT modeling environment.
Line Art Rendering
Adaptive extraction of isoparametric curves is employed herein to
create illustrative imagery exploiting diferent shaders. The image on
the left enhances silhouette regions while the image on the right uses
cosine shader.
Ruled Tracing
Ruled tracing of adaptive isoparametric curves is a novel rendering
technique to directly scan convert freeform parametric surfaces. Herein,
special affects such as texture and bump mapping are intermixed with
shadow computation. No polygnal approximation of the freeform surfaces
is involved in this process. Joint work with Postech, Korea.
Curvature Analysis of Freeform Surfaces
In this sequal, three images of the Utah Teapot are shown with color
maps that represents the Gaussian (left), Mean (middle), and sum of
squares of principle curvatures (sqrt(k1^2 + k2^2)). These curvature
properties were computed as scalar fields using tools provided in the
IRIT modeling environment,
were represented in piecewise polynomial parametric form, and were
rendered back on top of the Utah Teapot using the IRIT rendering tool that
supports texture mapping of scalar fields. In all three images, Red
denotes high values, Blue low values, and Green intermediate values.
Point-Curve Bisector Surface
The bisector surface of a curve and a point is rational! These
examples show the shape of the bisector
surface for a parabolic arc and a point in the plane (left) and out of
the plane (right). The left image shows that the point-curve bisector
is a special case of the curve-curve bisector with a vertical line.
Created using the IRIT modeling
environment as a joint work with Postech, Korea.
Curve-Curve Bisector Surface
The bisector surface of two rational space curves in general 3-space
position is rational! These examples show the shape of the bisector
surface for an ellipse and a line and for a round square and a line.
Both surfaces were computed symbolically and are represented using
rational forms. Created using the
IRIT modeling environment as a joint work with Postech, Korea.
Virtual Reality and the WWW
This project investigates the mean to map various data (text, images,
movies, sound, etc.) onto virtual environments. The two images provided
herein show examples of a simple virtual environment where the images
displayed are the result of a query posted to the network.
Created using the
IRIT modeling environment, Performer from SGI and
W3QS WWW
query language.
Line Art Rendering of Parametric and Implicit Forms
Line art illustrations are created in this project, using strokes that are
developed out of point distributions on the freeforms. This scheme can be
employed for both parametric and implicit forms.
Here, the chess set and the light bulbs are two examples of parametric
forms, whereas the tubes' joint is a result of an implicit iso surface defined
over a trivariate polynomial function and the facial figure is an output
of an iso surface extraction out of the MRBrain model from UNC. both last
examples employs the principal curvatures as the direction of the strokes.
Created using the IRIT modeling environment.