Visibility analysis is broadly used in milling and casting process planning and in coordinate measuring machine applications. However, standard visibility analysis (which involves determining visibility from a given viewpoint), cannot be applied directly to in-line cutting systems such as wire electrical discharge machines or hot wire foam cutters. The motivation of this paper is to accurately calculate the tangent visibility for objects represented by polygonal surfaces. In this paper we define a new type of visibility - tangent visibility. We develop an algorithm to calculate the global tangent visibility for in-line cutting systems, and several models are tested to verify its accuracy. Several polyhedral models are tested to verify the correctness of the tangent visibility algorithm; and the complexity of the algorithm is also discussed.

References

References
1.
Woo
,
T. C.
, 1994, “
Visibility Maps and Spherical Algorithms
,”
Comput.-Aided Des.
,
26
(
1
), pp.
6
16
.
2.
Balasubramaniam
,
M.
,
Sarma
,
S. E.
, and
Marciniak
,
K.
, 2003, “
Collision-Free Finishing Toolpaths From Visibility Data
,”
Comput.-Aided Des.
,
35
(
4
), pp.
359
374
.
3.
Li
,
Y.
, and
Frank
,
M. C.
, 2007, “
Computing Non-Visibility of Convex Polygonal Facets on the Surface of a Polyhedral CAD Model
,”
Comput.-Aided Des.
,
39
(
9
), pp.
732
744
.
4.
Yang
,
W.
,
Ding
,
H.
, and
Xiong
,
Y.
, 1999, “
Manufacturability Analysis for a Sculptured Surface Using Visibility Cone Computation
,”
Int. J. Adv. Manuf. Technol.
,
15
(
5
), pp.
317
321
.
5.
Yang
,
Z.
,
Wysk
,
R. A.
,
Joshi
,
S.
,
Frank
,
M. C.
, and
Petrzelka
,
J. E.
, 2009, “
Conventional Machining Methods for Rapid Prototyping and Direct Manufacturing
,”
Int. J. Rapid Manuf.
,
1
(
1
), pp.
41
64
.
6.
Yin
,
Z.-P.
,
Ding
,
H.
, and
Xiong
,
Y.-L.
, 2000, “
Visibility Theory and Algorithms With Application to Manufacturing Processes
,”
Int. J. Prod. Res.
,
38
(
13
), pp.
2891
2909
.
7.
Chen
,
Z. C.
,
Dong
,
Z.
, and
Vickers
,
G. W.
, 2003, “
Automated Surface Subdivision and Tool Path Generation for 3 1/2 1/2-Axis CNC Machining of Sculptured Parts
,”
Comput. Ind.
,
50
(
3
), pp.
319
331
.
8.
Kang
,
J.-K.
, and
Suh
,
S.-H.
, 1997, “
Machinability and Set-up Orientation for Five-Axis Numerically Controlled Machining of Free Surfaces
,”
Int. J. Adv. Manuf. Technol.
,
13
(
5
), pp.
311
325
.
9.
Ainsworth
,
I.
,
Ristic
,
M.
, and
Brujic
,
D.
, 2000, “
CAD-Based Measurement Path Planning for Free-Form Shapes Using Contact Probes
,”
Int. J. Adv. Manuf. Technol.
,
16
(
1
), pp.
23
31
.
10.
Elkott
,
D.
, and
Veldhuis
,
S.
, 2007, “
CAD-Based Sampling for Cmm Inspection of Models With Sculptured Features
,”
Eng. Comput.
,
23
(
3
), pp.
187
206
.
11.
Elkott
,
D. F.
,
Elmaraghy
,
H. A.
, and
Elmaraghy
,
W. H.
, 2002, “
Automatic Sampling for Cmm Inspection Planning of Free-Form Surfaces
,”
Int. J. Prod. Res.
,
40
(
1
), pp.
2653
2676
.
12.
Kramer
,
T. R.
,
Huang
,
H.
,
Messina
,
E.
,
Proctor
,
F. M.
, and
Scott
,
H.
, 2001, “
A Feature-Based Inspection and Machining System
,”
Comput.-Aided Des.
,
33
(
9
), pp.
653
669
.
13.
Kweon
,
S.
, and
Medeiros
,
D. J.
, 1998, “
Part Orientations for Cmm Inspection Using Dimensioned Visibility Maps
,”
Comput.-Aided Des.
,
30
(
9
), pp.
741
749
.
14.
Lin
,
Y. J.
, and
Murugappan
,
P.
, 2000, “
A New Algorithm for CAD-Directed Cmm Dimensional Inspection
,”
Int. J. Adv. Manuf. Technol.
,
16
(
2
), pp.
107
112
.
15.
Spitz
,
S. N.
,
Spyridi
,
A. J.
, and
Requicha
,
A. G.
, 1999, “
Accessibility Analysis for Planning of Dimensional Inspection With Coordinate Measuring Machines
,”
IEEE Trans. Rob. Autom.
,
15
(
4
), pp.
714
727
.
16.
Zhang
,
S. G.
,
Ajmal
,
A.
,
Wootton
,
J.
, and
Chisholm
,
A.
, 2000, “
A Feature-Based Inspection Process Planning System for Co-Ordinate Measuring Machine (Cmm)
,”
J. Mater. Process. Technol.
,
107
(
1–3
), pp.
111
118
.
17.
Chen
,
L.-L.
,
Chou
,
S.-Y.
, and
Woo
,
T. C.
, 1993, “
Parting Directions for Mould and Die Design
,”
Comput.-Aided Des.
,
25
(
12
), pp.
762
768
.
18.
Chen
,
L.-L.
,
Chou
,
S.-Y.
, and
Woo
,
T. C.
, 1995, “
Partial Visibility for Selecting a Parting Direction in Mold and Die Design
,”
J. Manuf. Syst.
,
14
(
5
), pp.
319
330
.
19.
Greiner
,
G.
, and
Hormann
,
K.
, 1998, “
Efficient Clipping of Arbitrary Polygons
,”
ACM Trans. Graphics
,
17
(
2
), pp.
71
83
.
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