Abstract
We introduce the concept ofsoft objects whose shape changes in response to their surroundings. Established geometric modelling techniques exist to handle most engineering components, including ‘free form’ shapes such as car bodies and telephones. More recently, there has been a lot of interest in modelling natural pheomena such as smoke, clouds, mountains and coastlines where the shapes are described stochastically, or as fractals. None of these techniques lends itself to the description ofsoft objects. This class of objects includes fabrics, cushions, living forms, mud and water. In this paper, we describe a method of modelling such objects and discuss its uses in animation. Our method is to represent asoft object, or collection of objects, as a surface of constant value in a scalar field over three dimensions. The main technical problem is to avoid calculating the field value at too many points. We do this with a combination of data structures at some cost in internal memory usage.
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References
Blinn J (1982) A Generalization of Algebraic Surface Drawing. ACM Transactions on Graphics 1:235–256
Fournier A, Fussel D, Carpenter L (1982) Computer Rendering of Stochastic Models. CACM 25:371–384
Gardner G (1985) Visual Simulation of Clouds. SIGGRAPH 85 Computer Graphics 19 (3):297–303
Nishimura H, Hirai M, Kawai T, Kawata T, Shirakawa I, Omura K (1985) Object Modeling by Distribution Function and a Method of Image Generation. Journal of papers given at the Electronics Communication Conference '85, vol. J 68-D No 4 (in Japanese)
Mandelbrot B (1982) The Fractal Geometry of Nature. W.H. Freeman, San Francisco
Perlin K (1985) An Image Synthesizer. SIGGRAPH 85 Computer Graphics 19 (3):287–296
Reeves W (1983) Particle Systems — A Technique for Modeling a Class of Fuzzy Objects. ACM Transactions on Graphics 2:91–108
Wyvill BLM, McPheeters C, Garbutt R (1985a) A Practical 3D Computer Animation System. The BKSTS Journal 67:328–332
Wyvill BLM, McPheeters C, Novacek M (1985b) Specifying Stochastic Objects in a Hierarchical Graphics System. Proceedings of Graphics Interface 85, Montreal, pp 17–20
Wyvill BLM, McPheeters C, Wyvill G (1986a) Animating Soft Objects. The Visual Computer 2:235–242
Wyvill G, McPheeters C, Wyvill BLM (1986b) Soft Objects. Advanced Computer Graphics. Proceedings of Computer Graphics Tokyo 86, pp 113–128
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Wyvill, G., McPheeters, C. & Wyvill, B. Data structure forsoft objects. The Visual Computer 2, 227–234 (1986). https://doi.org/10.1007/BF01900346
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DOI: https://doi.org/10.1007/BF01900346