Abstract
Physically based rendering, using path-space formulation of global illumination, has become a standard technique for high-quality computer-generated imagery. Nonetheless, being able to control and edit the resulting picture so that it corresponds to the artist vision is still a tedious trial-and-error process. We show how the manipulation of light transport translates into the path-space integral formulation of the rendering equation. We introduce portals as a path-space manipulation tool to edit and control renderings and show how our editing tool unifies and extends previous work on lighting editing. Portals allow the artist to precisely control the final aspect of the image without modifying neither scene geometry nor lighting setup. According to the setup of two geometric handles and a simple path selection filter, portals capture specific lightpaths and teleport them through 3D space. We implement portals in major path-based algorithms (Photon Mapping, Progressive Photon Mapping and Bi-directional Path Tracing) and demonstrate the wide range of control this technique allows on various lighting effects, from low-frequency color bleeding to high-frequency caustics as well as view-dependent reflections.
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References
Barzel, R.: Lighting controls for computer cinematography. J. Graph. Tools 2(1), 1–20 (1997)
Birn, J.: Digital Lighting and Rendering, 2nd edn. New Riders Publishing, Thousand Oaks (2005)
Blender Online Community: Blender—a 3d modelling and rendering package (2015). http://www.blender.org
Damez, C., Slusallek, P., Walter, B.J., Myszkowski, K., Wald, I., Christensen, P.H.: Global illumination for interactive applications and high-quality animations. SIGGRAPH 2003 Course Note #27, ACM, pp. 27–31. San Diego, USA (2003)
Hachisuka, T., Ogaki, S., Jensen, H.W.: Progressive photon mapping. ACM Trans. Graph. 27(5), 130:1–130:8 (2008)
Heckbert, P.S.: Adaptive radiosity textures for bidirectional ray tracing. SIGGRAPH Comput. Graph. 24(4), 145–154 (1990)
Jakob, W.: Mitsuba renderer (2010). http://www.mitsuba-renderer.org
Jensen, H.W.: A practical guide to global illumination using ray tracing and photon mapping. In: ACM SIGGRAPH 2004 Course Notes, SIGGRAPH ’04. ACM, New York (2004)
Kerr, W.B., Pellacini, F., Denning, J.D.: Bendylights: artistic control of direct illumination by curving light rays. Comput. Graph. Forum 29(4), 1451–1459 (2010)
Lafortune, E.P., Willems, Y.D.: Bi-directional path tracing. In: Proceedings Conference on Computational Graphics and Visualization Techniques, pp. 145–153 (1993)
Lagae, A., Dutré, P.: An efficient ray-quadrilateral intersection test. J. Graph. Tools 10(4), 23–32 (2005)
Mattausch, O., Igarashi, T., Wimmer, M.: Freeform shadow boundary editing. Comput. Graph. Forum 32, 175–184 (2013)
Nowrouzezahrai, D., Johnson, J., Selle, A., Lacewell, D., Kaschalk, M., Jarosz, W.: A programmable system for artistic volumetric lighting. ACM Trans. Graph. 30(4), 29:1–29:8 (2011)
Obert, J., Pellacini, F., Pattanaik, S.: Visibility editing for all-frequency shadow design. In: Proceedings of the 21st Eurographics Conference on Rendering, EGSR’10 (2010)
Okabe, M., Matsushita, Y., Shen, L., Igarashi, T.: Illumination brush: interactive design of all-frequency lighting. In: Proceedings of the 15th Pacific Conference on Computer Graphics and Applications, PG ’07, pp. 171–180. IEEE Computer Society, New York (2007)
Pellacini, F.: Envylight: an interface for editing natural illumination. ACM Trans. Graph. 29(4), 34:1–34:8 (2010)
Pellacini, F., Battaglia, F., Morley, R.K., Finkelstein, A.: Lighting with paint. ACM Trans. Graph. 26(2) (2007)
Pellacini, F., Tole, P., Greenberg, D.P.: A user interface for interactive cinematic shadow design. ACM Trans. Graph. 21(3), 563–566 (2002)
Raymond, B., Guennebaud, G., Barla, P., Pacanowski, R., Granier, X.: Optimizing BRDF orientations for the manipulation of anisotropic highlights. Comput. Graph. Forum 33(2), 313–321 (2002)
Reiner, T., Kaplanyan, A., Reinhard, M., Dachsbacher, C.: Selective inspection and interactive visualization of light transport in virtual scenes. Comput. Graph. Forum 31(2pt4), 711–718 (2012)
Ritschel, T., Okabe, M., Thormählen, T., Seidel, H.P.: Interactive reflection editing. ACM Trans. Graph. 28(5), 129:1–129:7 (2009)
Ritschel, T., Thormählen, T., Dachsbacher, C., Kautz, J., Seidel, H.P.: Interactive on-surface signal deformation. ACM Trans. Graph. 29(4), 36:1–36:8 (2010)
Schmidt, T-.W., Novák, J., Meng, J., Kaplanyan, A.S., Reiner, T., Nowrouzezahrai, D., Dachsbacher, C.: Path-space manipulation of physically-based light transport. ACM Trans. Graph. 32(4), 129:1–129:11 (2013)
Veach, E.: Robust monte carlo methods for light transport simulation. Ph.D. thesis, Chap. 4,8, Stanford, CA, USA (1998)
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We especially thank the Observatory of Systems Information Retrieval and Indexing of Multimedia contents (OSIRIM) platform of the Toulouse Institute of Computer Science Research (IRIT).
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Appendix
The edited path contribution measure is defined as
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Subileau, T., Mellado, N., Vanderhaeghe, D. et al. RayPortals: a light transport editing framework. Vis Comput 33, 129–138 (2017). https://doi.org/10.1007/s00371-015-1163-2
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DOI: https://doi.org/10.1007/s00371-015-1163-2