The notion of quantitative invisibility and the machine rendering of solids

ABSTRACT

Line drawings are the most common type of rendering used to convey geometrical description. This is due to the economy of preparing such drawings and the great information density obtainable. On a pure line drawing, that is where no attempt is made to specify or suggest shadows, tone or color, the lines rendered are either the intersection curves of surfaces or the contour curves of surfaces. The nature of these curves are adequately discussed in the literature 1 and in a previous report.2 In order to convey a realistic impression of an object or an assembly of objects, the segments of lines which cannot be seen by an observer are not drawn or are drawn dashed. Without specification of visibility a drawing is ambiguous. This paper presents a recently developed scheme for the determination of visibility in a line drawing which enables comparitively high speed calculation and excellent resolution.

REFERENCES

• 1: J. Y. 0S. Luh , R. J. Krolak, Mathematical model for mechanical part description, Communications of the ACM, v.8 n.2, p.125-129, Feb. 1965 [doi>10.1145/363744.363788]
• 2: A APPEL The visibility problem and machine rendering of solids IBM Research Report RC 1618 May 20 1966
• 3: E. E. Zajac, Computer-made perspective movies as a scientific and communication tool, Communications of the ACM, v.7 n.3, p.169-170, March 1964 [doi>10.1145/363958.363993]
• 4: P LOUTREL Determination of hidden edges in polyhedral figures: convex case Technical Report 400-145 Laboratory for Electroscience Research N. Y. U. September 1966
• 5: L G ROBERTS Machine perception of three-dimensional solids Technical Report No 315 Lincoln Laboratory MIT May 1963
• 6: Y OKAYA Graphic display of crystal structures: an example of man-machine interaction IBM Research Report RC 1706 November 3 1966
• 7: Ruth A. Weiss, BE VISION, A Package of IBM 7090 FORTRAN Programs to Draw Orthographic Views of Combinations of Plane and Quadric Surfaces, Journal of the ACM (JACM), v.13 n.2, p.194-204, April 1966 [doi>10.1145/321328.321330]

INDEX TERMS

Primary Classification:
  I. Computing Methodologies
  I.3 COMPUTER GRAPHICS
      I.3.5 Computational Geometry and Object Modeling
          Subjects: Curve, surface, solid, and object representations

Additional Classification:
  I. Computing Methodologies
  I.3 COMPUTER GRAPHICS
      I.3.3 Picture/Image Generation
          Subjects: Line and curve generation

General Terms:
Theory