Graphics Reference
In-Depth Information
After the marching cube algorithm finds the surface and its normals one can
render the surface with a rendering technique such as ray casting and Phong shading.
According to [THBP90], the algorithm has problems with thin surfaces and sharp
edges and is expensive compared with other surface methods.
A 2d version of the marching cubes algorithm, called the
marching squares algo-
rithm
, is described in [ScML98].
10.5
E
XERCISES
Section 10.3
10.3.1
Consider the cylinder
C
with base in the x-y plane and height 7 defined by
2
2
(
)
+-
(
)
x
-
3
y
5
=
4
.
Let
X
be the ray that starts at
p
= (-1,8,15) and has direction vector
v
= (1,-1,-2). Find the
first intersection of
X
with
C
in the following two cases:
(1)
C
has neither a top or bottom.
(2)
C
has both a top and bottom.
10.6
P
ROGRAMMING
P
ROJECTS
Section 10.2
10.2.1
A ray-tracing program
Build on programming project 9.4.1(a) and implement a
complete
ray-tracing program
for a world of spheres that includes shadows, reflections, and transparencies using the Phong
illumination model.
