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3D gradient enhancement

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Abstract

Enhancement can exaggerate visual details in both image processing and 3D rendering. In this paper, we adapt the gradient enhancement technique from image processing to 3D rendering through differentiating the rendering result with respect to the image space coordinates under point lighting. In this way, we can achieve 3D enhancement taking into account the gradient of geometry, projection transform, visibility and highlight. We also propose a tunable shape descriptor for users to achieve rendering results in different enhancement extent. Moreover, we extend this method to the environment lighting with some simplifications. Finally, we demonstrate that our method can handle the grazing angle area and the edges of sharp slope better than the previous method due to the gradient of the projection transform.

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References

  1. Ritschel, T., Smith, K., Ihrke, M., Grosch, T., Myszkowski, K., Seidel, H.-P.: 3d unsharp masking for scene coherent enhancement. ACM Trans. Graph. 27(3), 90 (2008)

    Article  Google Scholar 

  2. Vergne, R., Pacanowski, R., Barla, P., Granier, X., Schlick, C.: Light warping for enhanced surface depiction. ACM Trans. Graph. 28(3), 251–258 (2009)

    Article  Google Scholar 

  3. Saito, T., Takahashi, T.: Comprehensible rendering of 3-d shapes. ACM Trans. Graph. 24, 197–206 (1990)

    Google Scholar 

  4. Nienhaus, M., Dollner, J.: Blueprints—illustrating architecture and technical parts using hardware-accelerated non-photorealistic rendering. In: Graphics Interface, pp. 49–56 (2004)

    Google Scholar 

  5. Goodwin, T., Vollick, I., Hertzmann, A.: Isophote distance: a shading approach to artistic stroke thickness. In: Proc. International Symposium on Non Photorealistic Animation and Rendering (NPAR ’07), pp. 53–62. ACM, New York (2007)

    Chapter  Google Scholar 

  6. Miller, G.: Efficient algorithms for local and global accessibility shading. In: Proceedings of the 21st Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH ’94), New York, NY, USA, pp. 319–326. ACM, New York (1994)

    Chapter  Google Scholar 

  7. Pharr, M., Green, S.: GPU Gems, Ambient Occlusion. Addison-Wesley, Reading (2004)

    Google Scholar 

  8. Cignoni, P., Scopigno, R., Tarini, M.: A simple normal enhancement technique for interactive non-photorealistic renderings. Comput. Graph. 29(1), 125–133 (2005)

    Article  Google Scholar 

  9. Lee, Y., Markosian, L., Lee, S., Hughes, J.F.: Line drawings via abstracted shading. ACM Trans. Graph. 26(3), 18 (2007)

    Article  Google Scholar 

  10. Zhang, X., Chen, W., Fang, J., Wang, R., Peng, Q.: Perceptually-motivated shape exaggeration. Vis. Comput. 26(6–8), 985–995 (2010)

    Article  Google Scholar 

  11. Ihrke, M., Ritschel, T., Smith, K., Grosch, T., Myszkowski, K., Seidel, H.-P.: A perceptual evaluation of 3D unsharp masking. Proc. SPIE 49(0), 72400R–72400R–12 (2009)

    Article  Google Scholar 

  12. Vergne, R., Barla, P., Granier, X., Schlick, C.: Apparent relief: a shape descriptor for stylized shading. In: Proceedings of the 6th International Symposium on Non-Photorealistic Animation and Rendering (NPAR ’08), pp. 23–29. ACM, New York (2008)

    Chapter  Google Scholar 

  13. Vergne, R., Pacanowski, R., Barla, P., Granier, X., Schlick, C.: Radiance scaling for versatile surface enhancement. In: Proceedings of the 2010 ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games (I3D ’10), New York, NY, USA, pp. 143–150. ACM, New York (2010)

    Google Scholar 

  14. Kindlmann, G., Whitaker, R., Tasdizen, T., Moller, T.: Curvature-based transfer functions for direct volume rendering: methods and applications. In: Proceedings of the 14th IEEE Visualization 2003 (VIS ’03), Washington, DC, USA, p. 67. IEEE Comput. Society, Los Alamitos (2003)

    Google Scholar 

  15. Lee, C.H., Hao, X., Varshney, A.: Geometry-dependent lighting. IEEE Trans. Vis. Comput. Graph. 12(2), 197–207 (2006)

    Article  Google Scholar 

  16. Vergne, R., Pacanowski, R., Barla, P., Granier, X., Schlick, C.: Improving shape depiction under arbitrary rendering. IEEE Trans. Vis. Comput. Graph. 17, 1071–1081 (2011)

    Article  Google Scholar 

  17. Ramamoorthi, R., Mahajan, D., Belhumeur, P.: A first-order analysis of lighting, shading, and shadows. ACM Trans. Graph., 26, January 2007

  18. Vergne, R., Barla, P., Fleming, R.W., Granier, X.: Surface flows for image-based shading design. ACM Trans. Graph. 31(4), 941:1–949:9 (2012)

    Article  Google Scholar 

  19. Koenderink, J.J.: What does the occluding contour tell us about solid shape? Perception 13(3), 321–330 (1984)

    Article  Google Scholar 

  20. Gooch, B., Sloan, P.-P.J., Gooch, A., Shirley, P., Riesenfeld, R.: Interactive technical illustration. In: Proceedings of the 1999 Symposium on Interactive 3D Graphics (I3D ’99), New York, NY, USA, pp. 31–38. ACM, New York (1999)

    Chapter  Google Scholar 

  21. Hertzmann, A., Zorin, D.: Illustrating smooth surfaces. In: Proceedings of the 27th Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH ’00), New York, NY, USA, pp. 517–526. ACM, New York (2000)

    Chapter  Google Scholar 

  22. DeCarlo, D., Finkelstein, A., Rusinkiewicz, S., Santella, A.: Suggestive contours for conveying shape. ACM Trans. Graph. 22(3), 848–855 (2003)

    Article  Google Scholar 

  23. DeCarlo, D., Finkelstein, A., Rusinkiewicz, S.: Interactive rendering of suggestive contours with temporal coherence. In: Proceedings of the 3rd International Symposium on Non-Photorealistic Animation and Rendering (NPAR ’04), New York, NY, USA, pp. 15–145. ACM, New York (2004)

    Chapter  Google Scholar 

  24. Ohtake, Y., Belyaev, A., Seidel, H.-P.: Ridge-valley lines on meshes via implicit surface fitting. ACM Trans. Graph. 23(3), 609–612 (2004)

    Article  Google Scholar 

  25. Judd, T., Durand, F., Adelson, E.: Apparent ridges for line drawing. ACM Trans. Graph. 26(3) (2007)

  26. Kolomenkin, M., Shimshoni, I., Tal, A.: Demarcating curves for shape illustration. ACM Trans. Graph. 27(5), 1571–1579 (2008)

    Article  Google Scholar 

  27. DeCarlo, D., Rusinkiewicz, S.: Highlight lines for conveying shape. In: International Symposium on Non-Photorealistic Animation and Rendering (NPAR), August 2007

    Google Scholar 

  28. Belkin, M., Sun, J., Wang, Y.: Discrete Laplace operator on meshed surfaces. In: Proceedings of the Twenty-Fourth Annual Symposium on Computational Geometry (SCG ’08), pp. 278–287. ACM, New York (2008)

    Chapter  Google Scholar 

  29. Zhang, L., He, Y., Xie, X., Chen, W.: Laplacian lines for real-time shape illustration. In: Proc. Symposium on Interactive 3D Graphics and Games (I3D ’09) (2009)

    Google Scholar 

  30. Gonzalez, R.C., Woods, R.E.: Digital Image Processing, vol. 1, 2th edn. Pearson Education, Upper Saddle River (2007)

    Google Scholar 

  31. Kajiya, J.T.: The rendering equation. ACM Trans. Graph. 20, 143–150 (1986)

    Google Scholar 

  32. Rusinkiewicz, S.: Estimating curvatures and their derivatives on triangle meshes. In: Symposium on 3D Data Processing, Visualization, and Transmission, pp. 486–493 (September 2004)

    Google Scholar 

  33. Debevec, P.: Rendering synthetic objects into real scenes: bridging traditional and image-based graphics with global illumination and high dynamic range photography. In: Proceedings of the 25th Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH ’98), New York, NY, USA, pp. 189–198. ACM, New York (1998)

    Chapter  Google Scholar 

  34. Ashikmin, M., Premože, S., Shirley, P.: A microfacet-based BRDF generator. In: Proc. SIGGRAPH ’00, pp. 65–74. ACM, New York (2000)

    Chapter  Google Scholar 

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Acknowledgements

Many thanks to Romain Vergne et al. for sharing their OpenGL Shader source code, the anonymous reviewers for their valuable comments and Ming Zeng and Bo Jiang for proof reading. The testing scenes are courtesy of Stanford 3D Scanning Repository (Armadillo and Dragon). This work was partially supported by NSFC (No. 60970074), Fok Ying-Tong Education Foundation and the Fundamental Research Funds for the Central Universities.

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Correspondence to Fukai Zhao.

Appendix:  The derivation of ∇n(x), ∇G Ph(x) and ∇ω i (x)

Appendix:  The derivation of ∇n(x), ∇G Ph(x) and ∇ω i (x)

We take triangle meshes as the input data. Let T be the triangle that contains the point x. Denote the vertices of triangle T by x 0, x 1 and x 2. The barycentric coordinates, b v (x)=[b 0(x),b 1(x),b 2(x)]T, can be evaluated by

where |T| represents the area of the triangle, and n T is the normal of the triangle. Thus, we can interpolate the normal at point x by vertex normals N v of the triangle using the barycentric coordinates b v (x), and then normalize it as

$$\mathbf{n}(\mathbf{x}) = \frac{\mathbf{h}(\mathbf{x})}{\|\mathbf {h}(\mathbf{x})\|},\qquad \mathbf{h}(\mathbf{x}) = N_v \mathbf{b}_v(\mathbf{x}), $$

where N v =[n 0,n 1,n 2] is the matrix of vertex normals.

Therefore, the gradient of the normal can be approximated by

The gradient of barycentric coordinates, ∇b v (x), can be evaluated by

As we have defined G Ph(x)=〈r(x),ω o (x)〉a, we can evaluate its gradient as

According to the definition of r(x) in Sect. 3.2, its gradient can be evaluated by

The derivation of ∇n(x) is given in Sect. 3.2. The gradient of ω i (x) and ω o (x) can be evaluated by

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Zhao, F., Liu, X. 3D gradient enhancement. Vis Comput 30, 113–126 (2014). https://doi.org/10.1007/s00371-013-0787-3

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