Surface scratches: measuring, modeling and rendering

One of the most important criticisms that can be made concerning synthesized images is the brand new and too clean aspect of objects. Surface color modifications can be used to introduce dirtiness or other aging-linked characteristics. Also, techniques such as bump or displacement mapping allow users to improve surface aspects by introducing geometrical perturbations. In parallel, the bidirectional reflectance distribution function (BRDF) is a crucial factor in achieving a high degree of realism. It turns out that surfaces are very often covered by defects such as scratches that are related to both textures and BRDFs due to their size. Scratches do not always affect the apparent geometry but nevertheless can remain strongly visible. None of the previously mentioned methods is suited for rendering these defects efficiently. We propose a new method, based on extensions to existing BRDFs and classical 2D texture mapping techniques, to render efficiently individually visible scratches. We use physical measurements on "real objects" to derive an accurate geometric model of scratches at small scale range (roughness scale), and we introduce a new geometric level between bump mapping and BRDFs. Beyond providing graphical results closely matching real cases, our method opens the way to a new class of considerations in computer graphics based on defects that require the coupling of both BRDFs and texturing techniques.

[1]  Jos Stam,et al.  Diffraction shaders , 1999, SIGGRAPH.

[2]  Pat Hanrahan,et al.  Geometry Caching for Ray-Tracing Displacement Maps , 1996, Rendering Techniques.

[3]  Jean-Michel Dischler,et al.  A BRDF Postprocess to Integrate Porosity on Rendered Surfaces , 2000, IEEE Trans. Vis. Comput. Graph..

[4]  Robert L. Cook,et al.  Shade trees , 1984, SIGGRAPH.

[5]  Jean-Michel Dischler,et al.  Efficiently Rendering Macro Geometric Surface Structures with Bi-Directional Texture Functions , 1998, Rendering Techniques.

[6]  Hans-Peter Seidel,et al.  Ray-tracing Procedural Displacement Shaders , 1998, Graphics Interface.

[7]  Robert L. Cook,et al.  A Reflectance Model for Computer Graphics , 1987, TOGS.

[8]  Nelson L. Max,et al.  Bidirectional reflection functions from surface bump maps , 1987, SIGGRAPH.

[9]  Gregory J. Ward,et al.  Measuring and modeling anisotropic reflection , 1992, SIGGRAPH.

[10]  Mark S. Drew,et al.  Rendering Iridescent Colors of Optical Disks , 2000, Rendering Techniques.

[11]  James Arvo,et al.  A framework for realistic image synthesis , 1997, SIGGRAPH.

[12]  Stephen H. Westin,et al.  Predicting reflectance functions from complex surfaces , 1992, SIGGRAPH.

[13]  Victor Ng-Thow-Hing,et al.  Feature-based Displacement Mapping , 2000, Rendering Techniques.

[14]  Pierre Poulin,et al.  A Model for Anisotropic Reeection , 1990 .

[15]  Shree K. Nayar,et al.  Generalization of Lambert's reflectance model , 1994, SIGGRAPH.

[16]  Robert R. Lewis,et al.  Making Shaders More Physically Plausible , 1994, Comput. Graph. Forum.

[17]  Donald P. Greenberg,et al.  A comprehensive physical model for light reflection , 1991, SIGGRAPH.

[18]  Andrew S. Glassner,et al.  Principles of Digital Image Synthesis , 1995 .

[19]  Hans-Peter Seidel,et al.  Illuminating micro geometry based on precomputed visibility , 2000, SIGGRAPH.

[20]  Nelson L. Max,et al.  Smooth transitions between bump rendering algorithms , 1993, SIGGRAPH.

[21]  Gary W. Meyer,et al.  Wavelength dependent reflectance functions , 1994, SIGGRAPH.

[22]  Pat Hanrahan,et al.  Reflection from layered surfaces due to subsurface scattering , 1993, SIGGRAPH.

[23]  James T. Kajiya,et al.  The rendering equation , 1998 .

[24]  Edwin Earl Catmull,et al.  A subdivision algorithm for computer display of curved surfaces. , 1974 .

[25]  James T. Kajiya,et al.  Rendering fur with three dimensional textures , 1989, SIGGRAPH.

[26]  Pierre Poulin,et al.  A model for anisotropic reflection , 1990, SIGGRAPH.

[27]  Jean-Michel Dischler,et al.  Erndering Inhomogeneous Surfaces with Radiosity , 1999, Rendering Techniques.

[28]  Peter Shirley,et al.  Direct Ray Tracing of Displacement Mapped Triangles , 2000, Rendering Techniques.

[29]  Shree K. Nayar,et al.  Correlation model for 3D texture , 1999, Proceedings of the Seventh IEEE International Conference on Computer Vision.

[30]  James F. Blinn,et al.  Simulation of wrinkled surfaces , 1978, SIGGRAPH.

[31]  M. Pinar Mengüç,et al.  Thermal Radiation Heat Transfer , 2020 .

[32]  Bui Tuong Phong.  Illumination for computer generated pictures , 1975, Commun. ACM.

[33]  K. Torrance,et al.  Theory for off-specular reflection from roughened surfaces , 1967 .

[34]  Shree K. Nayar,et al.  Reflectance and texture of real-world surfaces , 1999, TOGS.