Survey of Texture Mapping
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Photorealistic Texturing for Dummies
PHOTOREALISTIC TEXTURING FOR DUMMIES Leigh Van Der Byl http://leigh.cgcommunity.com Compiled by Carlos Eduardo de Paula - Brazil PHOTOREALISTIC TEXTURING FOR DUMMIES Index Part 1 – An Introduction To Texturing ...............................................................................................3 Introduction ........................................................................................................................................................ 3 Why Procedural Textures just don't work ...................................................................................................... 3 Observing the Aspects of Surfaces In Real Life............................................................................................ 4 The Different Aspects Of Real World Surfaces ............................................................................................ 5 Colour................................................................................................................................................................... 5 Diffuse.................................................................................................................................................................. 5 Luminosity........................................................................................................................................................... 6 Specularity........................................................................................................................................................... -
Texture Mapping Textures Provide Details Makes Graphics Pretty
Texture Mapping Textures Provide Details Makes Graphics Pretty • Details creates immersion • Immersion creates fun Basic Idea Paint pictures on all of your polygons • adds color data • adds (fake) geometric and texture detail one of the basic graphics techniques • tons of hardware support Texture Mapping • Map between region of plane and arbitrary surface • Ensure “right things” happen as textured polygon is rendered and transformed Parametric Texture Mapping • Texture size and orientation tied to polygon • Texture can modulate diffuse color, specular color, specular exponent, etc • Separation of “texture space” from “screen space” • UV coordinates of range [0…1] Retrieving Texel Color • Compute pixel (u,v) using barycentric interpolation • Look up texture pixel (texel) • Copy color to pixel • Apply shading How to Parameterize? Classic problem: How to parameterize the earth (sphere)? Very practical, important problem in Middle Ages… Latitude & Longitude Distorts areas and angles Planar Projection Covers only half of the earth Distorts areas and angles Stereographic Projection Distorts areas Albers Projection Preserves areas, distorts aspect ratio Fuller Parameterization No Free Lunch Every parameterization of the earth either: • distorts areas • distorts distances • distorts angles Good Parameterizations • Low area distortion • Low angle distortion • No obvious seams • One piece • How do we achieve this? Planar Parameterization Project surface onto plane • quite useful in practice • only partial coverage • bad distortion when normals perpendicular Planar Parameterization In practice: combine multiple views Cube Map/Skybox Cube Map Textures • 6 2D images arranged like faces of a cube • +X, -X, +Y, -Y, +Z, -Z • Index by unnormalized vector Cube Map vs Skybox skybox background Cube maps map reflections to emulate reflective surface (e.g. -
Texture / Image-Based Rendering Texture Maps
Texture / Image-Based Rendering Texture maps Surface color and transparency Environment and irradiance maps Reflectance maps Shadow maps Displacement and bump maps Level of detail hierarchy CS348B Lecture 12 Pat Hanrahan, Spring 2005 Texture Maps How is texture mapped to the surface? Dimensionality: 1D, 2D, 3D Texture coordinates (s,t) Surface parameters (u,v) Direction vectors: reflection R, normal N, halfway H Projection: cylinder Developable surface: polyhedral net Reparameterize a surface: old-fashion model decal What does texture control? Surface color and opacity Illumination functions: environment maps, shadow maps Reflection functions: reflectance maps Geometry: bump and displacement maps CS348B Lecture 12 Pat Hanrahan, Spring 2005 Page 1 Classic History Catmull/Williams 1974 - basic idea Blinn and Newell 1976 - basic idea, reflection maps Blinn 1978 - bump mapping Williams 1978, Reeves et al. 1987 - shadow maps Smith 1980, Heckbert 1983 - texture mapped polygons Williams 1983 - mipmaps Miller and Hoffman 1984 - illumination and reflectance Perlin 1985, Peachey 1985 - solid textures Greene 1986 - environment maps/world projections Akeley 1993 - Reality Engine Light Field BTF CS348B Lecture 12 Pat Hanrahan, Spring 2005 Texture Mapping ++ == 3D Mesh 2D Texture 2D Image CS348B Lecture 12 Pat Hanrahan, Spring 2005 Page 2 Surface Color and Transparency Tom Porter’s Bowling Pin Source: RenderMan Companion, Pls. 12 & 13 CS348B Lecture 12 Pat Hanrahan, Spring 2005 Reflection Maps Blinn and Newell, 1976 CS348B Lecture 12 Pat Hanrahan, Spring 2005 Page 3 Gazing Ball Miller and Hoffman, 1984 Photograph of mirror ball Maps all directions to a to circle Resolution function of orientation Reflection indexed by normal CS348B Lecture 12 Pat Hanrahan, Spring 2005 Environment Maps Interface, Chou and Williams (ca. -
Vzorová Prezentace Dcgi
Textures Jiří Bittner, Vlastimil Havran Textures . Motivation - What are textures good for? MPG 13 . Texture mapping principles . Using textures in rendering . Summary 2 Textures Add Details 3 Cheap Way of Increasing Visual Quality 4 Textures - Introduction . Surface macrostructure . Sub tasks: - Texture definition: image, function, … - Texture mapping • positioning the texture on object (assigning texture coordinates) - Texture rendering • what is influenced by texture (modulating color, reflection, shape) 5 Typical Use of (2D) Texture . Texture coordinates (u,v) in range [0-1]2 u brick wall texel color v (x,y,z) (u,v) texture spatial parametric image coordinates coordinates coordinates 6 Texture Data Source . Image - Data matrix - Possibly compressed . Procedural - Simple functions (checkerboard, hatching) - Noise functions - Specific models (marvle, wood, car paint) 8 Texture Dimension . 2D – images . 1D – transfer function (e.g. color of heightfield) . 3D – material from which model is manufactured (wood, marble, …) - Hypertexture – 3D model of partly transparent materials (smoke, hair, fire) . +Time – animated textures 9 Texture Data . Scalar values - weight, intensity, … . Vectors - color - spectral color 10 Textures . Motivation - What are textures good for? MPG 13 . Texture mapping principles . Using textures in rendering . Summary 11 Texture Mapping Principle Texture application Planar Mapping texture 2D image to 3D surface (Inverse) texture mapping T: [u v] –> Color M: [x y z] –> [u v] M ◦ T: [x y z] –> [u v] –> Color 12 Texture Mapping – Basic Principles . Inverse mapping . Geometric mapping using proxy surface . Environment mapping 13 Inverse Texture Mapping – Simple Shapes . sphere, toroid, cube, cone, cylinder T(u,v) (M ◦ T) (x,y,z) v z v y u u x z z [x, y, z] r r h y β α y x x [u,v]=[0,0.5] [u,v]=[0,0] 14 Texture Mapping using Proxy Surface . -
Deconstructing Hardware Usage for General Purpose Computation on Gpus
Deconstructing Hardware Usage for General Purpose Computation on GPUs Budyanto Himawan Manish Vachharajani Dept. of Computer Science Dept. of Electrical and Computer Engineering University of Colorado University of Colorado Boulder, CO 80309 Boulder, CO 80309 E-mail: {Budyanto.Himawan,manishv}@colorado.edu Abstract performance, in 2001, NVidia revolutionized the GPU by making it highly programmable [3]. Since then, the programmability of The high-programmability and numerous compute resources GPUs has steadily increased, although they are still not fully gen- on Graphics Processing Units (GPUs) have allowed researchers eral purpose. Since this time, there has been much research and ef- to dramatically accelerate many non-graphics applications. This fort in porting both graphics and non-graphics applications to use initial success has generated great interest in mapping applica- the parallelism inherent in GPUs. Much of this work has focused tions to GPUs. Accordingly, several works have focused on help- on presenting application developers with information on how to ing application developers rewrite their application kernels for the perform the non-trivial mapping of general purpose concepts to explicitly parallel but restricted GPU programming model. How- GPU hardware so that there is a good fit between the algorithm ever, there has been far less work that examines how these appli- and the GPU pipeline. cations actually utilize the underlying hardware. Less attention has been given to deconstructing how these gen- This paper focuses on deconstructing how General Purpose ap- eral purpose application use the graphics hardware itself. Nor has plications on GPUs (GPGPU applications) utilize the underlying much attention been given to examining how GPUs (or GPU-like GPU pipeline. -
Environment Mapping
Environment Mapping Computer Graphics CSE 167 Lecture 13 CSE 167: Computer graphics • Environment mapping – An image‐based lighting method – Approximates the appearance of a surface using a precomputed texture image (or images) – In general, the fastest method of rendering a surface CSE 167, Winter 2018 2 More realistic illumination • In the real world, at each point in a scene, light arrives from all directions (not just from a few point light sources) – Global illumination is a solution, but is computationally expensive – An alternative to global illumination is an environment map • Store “omni‐directional” illumination as images • Each pixel corresponds to light from a certain direction • Sky boxes make for great environment maps CSE 167, Winter 2018 3 Based on slides courtesy of Jurgen Schulze Reflection mapping • Early (earliest?) non‐decal use of textures • Appearance of shiny objects – Phong highlights produce blurry highlights for glossy surfaces – A polished (shiny) object reflects a sharp image of its environment 2004] • The whole key to a Adelson & shiny‐looking material is Willsky, providing something for it to reflect [Dror, CSE 167, Winter 2018 4 Reflection mapping • A function from the sphere to colors, stored as a texture 1976] Newell & [Blinn CSE 167, Winter 2018 5 Reflection mapping • Interface (Lance Williams, 1985) Video CSE 167, Winter 2018 6 Reflection mapping • Flight of the Navigator (1986) CSE 167, Winter 2018 7 Reflection mapping • Terminator 2 (1991) CSE 167, Winter 2018 8 Reflection mapping • Star Wars: Episode -
Ray Tracing Notes CS445 Computer Graphics, Fall 2012 (Last Modified
Ray Tracing Notes CS445 Computer Graphics, Fall 2012 (last modified 10/7/12) Jenny Orr, Willamette University 1 The Ray Trace Algorithm refracted ray re!ected ray camera pixel Light3 light ray computed ray screen in shadow Light1 Light2 Figure 1 1 For each pixel in image { 2 compute ray 3 pixel_color = Trace(ray) 4 } 5 color Trace(ray) { 6 For each object 7 find intersection (if any) 8 check if intersection is closest 9 If no intersection exists 10 color = background color 11 else for the closest intersection 12 for each light // local color 13 color += ambient 14 if (! inShadow(shadowRay)) color += diffuse + specular 15 if reflective 16 color += k_r Trace(reflected ray) 17 if refractive 18 color += k_t Trace(transmitted ray) 19 return color 20 } 21 boolean inShadow(shadowRay) { 22 for each object 23 if object intersects shadowRay return true 24 return false 25 } 1 1.1 Complexity w = width of image h = height of image n = number of objects l = number of lights d = levels of recursion for reflection/refraction Assuming no recursion or shadows O(w ∗ h ∗ (n + l ∗ n)). How does this change if shadows and recursion are added? What about anti-aliasing? 2 Computing the Ray In general, points P on a ray can be expressed parametrically as P = P0 + t dir where P0 is the starting point, dir is a unit vector pointing in the ray's direction, and t ≥ 0 is the parameter. When t = 0, P corresponds to P0 and as t increases, P moves along the ray. In line 2 of the code, we calculate a ray which starts at the camera P0 and points from P0 to the given pixel located at P1 on a virtual screen (view plane), as shown in Figure 2. -
Texture Mapping Modeling an Orange
Texture Mapping Modeling an Orange q Problem: Model an orange (the fruit) q Start with an orange-colored sphere – Too smooth q Replace sphere with a more complex shape – Takes too many polygons to model all the dimples q Soluon: retain the simple model, but add detail as a part of the rendering process. 1 Modeling an orange q Surface texture: we want to model the surface features of the object not just the overall shape q Soluon: take an image of a real orange’s surface, scan it, and “paste” onto a simple geometric model q The texture image is used to alter the color of each point on the surface q This creates the ILLUSION of a more complex shape q This is efficient since it does not involve increasing the geometric complexity of our model Recall: Graphics Rendering Pipeline Application Geometry Rasterizer 3D 2D input CPU GPU output scene image 2 Rendering Pipeline – Rasterizer Application Geometry Rasterizer Image CPU GPU output q The rasterizer stage does per-pixel operaons: – Turn geometry into visible pixels on screen – Add textures – Resolve visibility (Z-buffer) From Geometry to Display 3 Types of Texture Mapping q Texture Mapping – Uses images to fill inside of polygons q Bump Mapping – Alter surface normals q Environment Mapping – Use the environment as texture Texture Mapping - Fundamentals q A texture is simply an image with coordinates (s,t) q Each part of the surface maps to some part of the texture q The texture value may be used to set or modify the pixel value t (1,1) (199.68, 171.52) Interpolated (0.78,0.67) s (0,0) 256x256 4 2D Texture Mapping q How to map surface coordinates to texture coordinates? 1. -
Ahenvironmentlight Version 3.0 for DAZ Studio Version 3.0.1.139 and Above
ahEnvironmentLight V3 for DAZ Studio 3.0 by Pendragon - Manual Page 1 of 32 © 2009 by Arthur Heinz - All Rights Reserved. ahEnvironmentLight Version 3.0 for DAZ Studio Version 3.0.1.139 and above Arthur Heinz aka “Pendragon” <[email protected]> ahEnvironmentLight V3 for DAZ Studio 3.0 by Pendragon - Manual Page 2 of 32 © 2009 by Arthur Heinz - All Rights Reserved. Table of Contents Featured Highlights of Version 3.0 ...................................................................................................................4 Quick Start........................................................................................................................................................5 Where to find the various parts....................................................................................................................5 Loading and rendering a scene with the IBL light........................................................................................6 New features concerning setup...................................................................................................................8 Preview Light..........................................................................................................................................8 Internal IBL Image Rotation Parameters...............................................................................................10 Overall Illumination Settings.................................................................................................................10 -
A Snake Approach for High Quality Image-Based 3D Object Modeling
A Snake Approach for High Quality Image-based 3D Object Modeling Carlos Hernandez´ Esteban and Francis Schmitt Ecole Nationale Superieure´ des Tel´ ecommunications,´ France e-mail: carlos.hernandez, francis.schmitt @enst.fr f g Abstract faces. They mainly work for 2.5D surfaces and are very de- pendent on the light conditions. A third class of methods In this paper we present a new approach to high quality 3D use the color information of the scene. The color informa- object reconstruction by using well known computer vision tion can be used in different ways, depending on the type of techniques. Starting from a calibrated sequence of color im- scene we try to reconstruct. A first way is to measure color ages, we are able to recover both the 3D geometry and the consistency to carve a voxel volume [28, 18]. But they only texture of the real object. The core of the method is based on provide an output model composed of a set of voxels which a classical deformable model, which defines the framework makes difficult to obtain a good 3D mesh representation. Be- where texture and silhouette information are used as exter- sides, color consistency algorithms compare absolute color nal energies to recover the 3D geometry. A new formulation values, which makes them sensitive to light condition varia- of the silhouette constraint is derived, and a multi-resolution tions. A different way of exploiting color is to compare local gradient vector flow diffusion approach is proposed for the variations of the texture such as in cross-correlation methods stereo-based energy term. -
IBL in GUI for Mobile Devices Andreas Nilsson
LiU-ITN-TEK-A--11/025--SE IBL in GUI for mobile devices Andreas Nilsson 2011-05-11 Department of Science and Technology Institutionen för teknik och naturvetenskap Linköping University Linköpings universitet SE-601 74 Norrköping, Sweden 601 74 Norrköping LiU-ITN-TEK-A--11/025--SE IBL in GUI for mobile devices Examensarbete utfört i medieteknik vid Tekniska högskolan vid Linköpings universitet Andreas Nilsson Examinator Ivan Rankin Norrköping 2011-05-11 Upphovsrätt Detta dokument hålls tillgängligt på Internet – eller dess framtida ersättare – under en längre tid från publiceringsdatum under förutsättning att inga extra- ordinära omständigheter uppstår. Tillgång till dokumentet innebär tillstånd för var och en att läsa, ladda ner, skriva ut enstaka kopior för enskilt bruk och att använda det oförändrat för ickekommersiell forskning och för undervisning. Överföring av upphovsrätten vid en senare tidpunkt kan inte upphäva detta tillstånd. All annan användning av dokumentet kräver upphovsmannens medgivande. För att garantera äktheten, säkerheten och tillgängligheten finns det lösningar av teknisk och administrativ art. Upphovsmannens ideella rätt innefattar rätt att bli nämnd som upphovsman i den omfattning som god sed kräver vid användning av dokumentet på ovan beskrivna sätt samt skydd mot att dokumentet ändras eller presenteras i sådan form eller i sådant sammanhang som är kränkande för upphovsmannens litterära eller konstnärliga anseende eller egenart. För ytterligare information om Linköping University Electronic Press se förlagets hemsida http://www.ep.liu.se/ Copyright The publishers will keep this document online on the Internet - or its possible replacement - for a considerable time from the date of publication barring exceptional circumstances. The online availability of the document implies a permanent permission for anyone to read, to download, to print out single copies for your own use and to use it unchanged for any non-commercial research and educational purpose. -
UNWRELLA Step by Step Unwrapping and Texture Baking Tutorial
Introduction Content Defining Seams in 3DSMax Applying Unwrella Texture Baking Final result UNWRELLA Unwrella FAQ, users manual Step by step unwrapping and texture baking tutorial Unwrella UV mapping tutorial. Copyright 3d-io GmbH, 2009. All rights reserved. Please visit http://www.unwrella.com for more details. Unwrella Step by Step automatic unwrapping and texture baking tutorial Introduction 3. Introduction Content 4. Content Defining Seams in 3DSMax 10. Defining Seams in Max Applying Unwrella Texture Baking 16. Applying Unwrella Final result 20. Texture Baking Unwrella FAQ, users manual 29. Final Result 30. Unwrella FAQ, user manual Unwrella UV mapping tutorial. Copyright 3d-io GmbH, 2009. All rights reserved. Please visit http://www.unwrella.com for more details. Introduction In this comprehensive tutorial we will guide you through the process of creating optimal UV texture maps. Introduction Despite the fact that Unwrella is single click solution, we have created this tutorial with a lot of material explaining basic Autodesk 3DSMax work and the philosophy behind the „Render to Texture“ workflow. Content Defining Seams in This method, known in game development as texture baking, together with deployment of the Unwrella plug-in achieves the 3DSMax following quality benchmarks efficiently: Applying Unwrella - Textures with reduced texture mapping seams Texture Baking - Minimizes the surface stretching Final result - Creates automatically the largest possible UV chunks with maximal use of available space Unwrella FAQ, users manual - Preserves user created UV Seams - Reduces the production time from 30 minutes to 3 Minutes! Please follow these steps and learn how to utilize this great tool in order to achieve the best results in minimum time during your everyday productions.