臺灣博碩士論文加值系統

In this paper, we will discuss the possibility of automating the process of lighting setup in computer graphics. We focus on a well-established technique known as “three-point lighting”. We devised a process of lighting setup automation based on the features of the given 3D model. This process is unsupervised, and employs a clustering technique to limit potential lighting positions into a controllable set. The parameters used for acquiring the final results can be easily tweaked to suit different applications and lighting styles.

Abstract 2
Table of Contents 3
1. Introduction 4
2. Related Work 6
2.1 Lighting Designs 6
2.1.1 Exterior Architectural Lighting 6
2.1.2 Stage Lighting 6
2.1.3 Subject Lighting 7
2.2 Perception of Shapes 7
2.3 Model Feature Extraction 8

3. Three Point Lighting 9
3.1 Key Light 9
3.2 Fill Light 9
3.2.1 Key-to-Fill Ratio 10
3.3 Back Light 10

4. Our Approach 13
4.1 Feature Extraction 13
4.2 Lights Positioning 14
4.2.1 Key Light Positioning 16
4.2.2 Fill Light Positioning 16
4.2.3 Back Light Positioning 16
4.3 Combined Result 18

5. Results and Discussion 21
6. Conclusion 29
7. References 31

[1] Blake, A. and Bulthoff, H. (1991) Shape from Specularities - Computation and Psychophysics, Philosophical Transactions of the Royal Society of London, Series B, Vol. 331, No. 1260, pp.237-252.

[2] Norman, J. F., Todd, J. T. & Orban, G. A. (2004) Perception of Three-Dimensional Shape From Specular Highlights, Deformations of Shading, and Other Types of Visual Information. Psychological Science, 15, 565-570.

[3] Girshick, A., V. Interrante, S. Haker, T. Lemoine. Line Direction Matters: An Argument for the Use of Principal Directions in 3D Line Drawings. Proceedings of the First International Symposium on Non Photorealistic Animation and Rendering (NPAR 2000), June 5-7, 2000, Annecy, France, pp. 43-52.

[4] Ahna Girshick , Victoria Interrante, Real-time principal direction line drawings of arbitrary 3D surfaces, ACM SIGGRAPH 99 Conference abstracts and applications, p.271, August 08-13, 1999, Los Angeles, California, United States

[5] Interrante, Fuchs and Pizer. "Conveying the 3D Shape of Smoothly Curving Transparent Surfaces via Texture", IEEE Transactions on Visualization and Computer Graphics, 3(2):98-117

[6] P.Samson and J.Mallet. Curvature Analysis of Triangulated Surfaces in Structural Geology. Mathematical Geology, 29(3):391-412, 1997.

[7] "Curved PN Triangles", 2001 ACM Symposium on Interactive 3D Graphics, Vlachos, Peters, Boyd, Mitchell, 2001

[8] Michael A. Kowalski, Lee Markosian, J.D. Northrup, Lubomir Bourdev, Ronen Barzel, Loring S. Holden and John F. Hughes. Art-Based Rendering of Fur, Grass, and Trees. Proceedings of SIGGRAPH '99.

[9] Markosian, L., Kowalski, M. A., Trychin, S. J., Bourdev, L. D., Goldstein, D., And Hughes, J. F. 1997. Real-time Nonphotorealistic Rendering. Proceedings of SIGGRAPH 97, 415–420.