# Intro to Ray-Tracing & Ray-Surface Acceleration

Size: px
Start display at page:

Download "Intro to Ray-Tracing & Ray-Surface Acceleration"

Transcription

1 Lecture 12 & 13: Intro to Ray-Tracing & Ray-Surface Acceleration Computer Graphics and Imaging UC Berkeley

2 Course Roadmap Rasterization Pipeline Core Concepts Sampling Antialiasing Transforms Geometric Modeling Core Concepts Splines, Bezier Curves Topological Mesh Representations Subdivision, Geometry Processing Rasterization Transforms & Projection Texture Mapping Visibility, Shading, Overall Pipeline Intro to Geometry Curves and Surfaces Geometry Processing Today: Ray-Tracing & Acceleration Lighting & Materials Cameras & Imaging

3 Basic Ray-Tracing Algorithm

4 Light Rays Three ideas about light rays 1. Light travels in straight lines (mostly) 2. Light rays do not interfere with each other if they cross (photons do not have interactions; ignoring wave effects like interference) 3. Light rays travel from the light sources to the eye (but the physics is invariant under path reversal - reciprocity).

5 Ray Casting Appel Ray casting 1. Generate an image by casting one ray per pixel 2. Check for shadows by sending a ray to the light

6 Ray Casting - Generating Eye Rays Pinhole Camera Model eye ray (starts at eye and goes through pixel) closest scene intersection point note: more intersection points eye point image plane light source

7 Ray Casting - Shading Pixels (Local Only) Pinhole Camera Model eye ray (starts at eye and goes through pixel) eye point image plane perform shading calculation here to compute color of pixel (e.g. Blinn Phong model) light source

8 Discussion: Ray Casting vs Rasterization Remember: Rasterization: 4x4 perspective matrix, project triangles to 2D screen, rasterize pixels Ray Casting: shoot rays through pixels into scene, intersect with triangles Discussion topics: Will they make the same picture? Which algorithm is faster, when? Other pros/cons? When would you use each algorithm, and why?

9 Discussion: Ray Casting vs Rasterization Will they make the same picture? Which algorithm is faster, when? Other pros/cons? When would you use each algorithm, and why? Ray approach better shaded than the rasterization? Shadows, sense of depth? Ray casting would be inefficient with respect to occlusion What happens when light is at the eye? Probably the same image? Because the same shading models? Transparency might change equivalence between models Ray casting, for every pixel must intersect against all triangles, very slow! Might need O(log n) algorithm, n number of triangles.

10 Recursive Ray Tracing An improved Illumination model for shaded display T. Whitted, CACM 1980 Time: VAX 11/780 (1979) 74m PC (2006) 6s GPU (2012) 1/30s Spheres and Checkerboard, T. Whitted, 1979

11 Recursive Ray Tracing eye point image plane light source

12 Recursive Ray Tracing Mirror ray (specular reflection) eye point image plane light source

13 Recursive Ray Tracing Refractive rays (specular transmission) eye point image plane light source

14 Recursive Ray Tracing eye point image plane light source Shadow rays

15 Recursive Ray Tracing secondary rays primary ray eye point image plane light source shadow rays Trace secondary rays recursively until hit a non-specular surface (or max desired levels of recursion) At each hit point, trace shadow rays to test light visibility (no contribution if blocked) Final pixel color is weighted sum of contributions along rays, as shown Gives more sophisticated effects (e.g. specular reflection, refraction, shadows), but we will go much further to derive a physically-based illumination model

16 Recursive Ray Tracing

17 Ray-Surface Intersection

18 Ray Intersection With Triangle Mesh Why? Rendering: visibility, shadows, lighting Geometry: inside/outside test How to compute? Let s break this down: Simple idea: just intersect ray with each triangle Simple, but slow (accelerate next time) Note: can have 0, 1 or multiple intersections

19 Ray Equation Ray is defined by its origin and a direction vector Example: Ray equation: 0 apple t<1 point along ray time origin unit direction

20 Plane Equation Plane is defined by normal vector and a point on plane Example: p 0 ) Plane Equation: 0 p :(p p 0 ) N =0 ax + by + cz + d =0 all points on plane any point normal vector

21 Ray Intersection With Plane Ray equation: r(t) =o + t d, 0 apple t<1 0 Plane equation: p :(p p 0 ) N =0 p 0 ) Solve for intersection Set p = r(t) and solve for t (p p 0 ) N =(o + t d p 0 ) N =0 t = (p0 o) N Check: 0 apple t<1 d N

22 Ray Intersection With Triangle Triangle is in a plane Ray-plane intersection Test if hit point is inside triangle (Assignment 1!) Many ways to optimize

23 Möller Trumbore Algorithm Why care about performance?

24 Ray Intersection With Sphere Ray: r(t) =o + t d, 0 apple t<1 0 Sphere: p :(p c) 2 R 2 =0 (p R 2 c) Solve for intersection: (o + t d c) 2 R 2 =0 at 2 + bt+ c =0, where t = b ± p b 2 4ac 2a a = d d b = 2(o c) d c =(o c) (o c) R 2

25 Ray Intersection With Implicit Surface Ray: 0 r(t) =o + t d, 0 apple t<1 General implicit surface: p : f(p) =0 Substitute ray equation: f(o + t d) =0 Solve for real, positive roots

26 Accelerating Ray-Surface Intersection

27 Ray Tracing Performance Challenges Simple ray-scene intersection Exhaustively test ray-intersection with every object Problem: Exhaustive algorithm = #pixels #objects Very slow!

28 Ray Tracing Performance Challenges Jun Yan, Tracy Renderer San Miguel Scene, 10.7M triangles

29 Ray Tracing Performance Challenges Deussen et al; Pharr & Humphreys, PBRT Plant Ecosystem, 20M triangles

30 Discussion: Accelerating Ray-Scene Intersection Deussen et al; Pharr & Humphreys, PBRT Next time: Brainstorm 3-4 accelerations, small or big ideas

31 To Be Continued

32 Acknowledgments Thanks to Pat Hanrahan, Kayvon Fatahalian, Mark Pauly and Steve Marschner for lecture resources.

### Accelerating Ray-Tracing

Lecture 9: Accelerating Ray-Tracing Computer Graphics and Imaging UC Berkeley CS184/284A, Spring 2016 Course Roadmap Rasterization Pipeline Core Concepts Sampling Antialiasing Transforms Geometric Modeling

More information

### CS354 Computer Graphics Ray Tracing. Qixing Huang Januray 24th 2017

CS354 Computer Graphics Ray Tracing Qixing Huang Januray 24th 2017 Graphics Pipeline Elements of rendering Object Light Material Camera Geometric optics Modern theories of light treat it as both a wave

More information

### Ray Tracing I: Basics

Ray Tracing I: Basics Today Basic algorithms Overview of pbrt Ray-surface intersection Next lecture Techniques to accelerate ray tracing of large numbers of geometric primitives Light Rays Three ideas

More information

### Lighting. To do. Course Outline. This Lecture. Continue to work on ray programming assignment Start thinking about final project

To do Continue to work on ray programming assignment Start thinking about final project Lighting Course Outline 3D Graphics Pipeline Modeling (Creating 3D Geometry) Mesh; modeling; sampling; Interaction

More information

### COMP 4801 Final Year Project. Ray Tracing for Computer Graphics. Final Project Report FYP Runjing Liu. Advised by. Dr. L.Y.

COMP 4801 Final Year Project Ray Tracing for Computer Graphics Final Project Report FYP 15014 by Runjing Liu Advised by Dr. L.Y. Wei 1 Abstract The goal of this project was to use ray tracing in a rendering

More information

### CS348B Lecture 2 Pat Hanrahan, Spring Greeks: Do light rays proceed from the eye to the light, or from the light to the eye?

Page 1 Ray Tracing Today Basic algorithms Overview of pbrt Ray-surface intersection for single surface Next lecture Acceleration techniques for ray tracing large numbers of geometric primitives Classic

More information

### Rendering: Reality. Eye acts as pinhole camera. Photons from light hit objects

Basic Ray Tracing Rendering: Reality Eye acts as pinhole camera Photons from light hit objects Rendering: Reality Eye acts as pinhole camera Photons from light hit objects Rendering: Reality Eye acts as

More information

### Topic 12: Texture Mapping. Motivation Sources of texture Texture coordinates Bump mapping, mip-mapping & env mapping

Topic 12: Texture Mapping Motivation Sources of texture Texture coordinates Bump mapping, mip-mapping & env mapping Texture sources: Photographs Texture sources: Procedural Texture sources: Solid textures

More information

### Computer Graphics. - Ray Tracing I - Marcus Magnor Philipp Slusallek. Computer Graphics WS05/06 Ray Tracing I

Computer Graphics - Ray Tracing I - Marcus Magnor Philipp Slusallek Overview Last Lecture Introduction Today Ray tracing I Background Basic ray tracing What is possible? Recursive ray tracing algorithm

More information

### Ray Tracing. Brian Curless CSEP 557 Fall 2016

Ray Tracing Brian Curless CSEP 557 Fall 2016 1 Reading Required: Shirley, section 10.1-10.7 (online handout) Triangle intersection (online handout) Further reading: Shirley errata on syllabus page, needed

More information

### Computer Graphics. Lecture 13. Global Illumination 1: Ray Tracing and Radiosity. Taku Komura

Computer Graphics Lecture 13 Global Illumination 1: Ray Tracing and Radiosity Taku Komura 1 Rendering techniques Can be classified as Local Illumination techniques Global Illumination techniques Local

More information

### Topic 11: Texture Mapping 11/13/2017. Texture sources: Solid textures. Texture sources: Synthesized

Topic 11: Texture Mapping Motivation Sources of texture Texture coordinates Bump mapping, mip mapping & env mapping Texture sources: Photographs Texture sources: Procedural Texture sources: Solid textures

More information

### CPSC GLOBAL ILLUMINATION

CPSC 314 21 GLOBAL ILLUMINATION Textbook: 20 UGRAD.CS.UBC.CA/~CS314 Mikhail Bessmeltsev ILLUMINATION MODELS/ALGORITHMS Local illumination - Fast Ignore real physics, approximate the look Interaction of

More information

### Topic 11: Texture Mapping 10/21/2015. Photographs. Solid textures. Procedural

Topic 11: Texture Mapping Motivation Sources of texture Texture coordinates Bump mapping, mip mapping & env mapping Topic 11: Photographs Texture Mapping Motivation Sources of texture Texture coordinates

More information

### Ray tracing. Computer Graphics COMP 770 (236) Spring Instructor: Brandon Lloyd 3/19/07 1

Ray tracing Computer Graphics COMP 770 (236) Spring 2007 Instructor: Brandon Lloyd 3/19/07 1 From last time Hidden surface removal Painter s algorithm Clipping algorithms Area subdivision BSP trees Z-Buffer

More information

### Ray Tracing. CPSC 453 Fall 2018 Sonny Chan

Ray Tracing CPSC 453 Fall 2018 Sonny Chan Ray Tracing A method for synthesizing images of virtual 3D scenes. Image Capture Devices Which one shall we use? Goal: Simulate a Camera Obscura! Spheres & Checkerboard

More information

### Ray Tracing Basics I. Computer Graphics as Virtual Photography. camera (captures light) real scene. photo. Photographic print. Photography: processing

Ray Tracing Basics I Computer Graphics as Virtual Photography Photography: real scene camera (captures light) photo processing Photographic print processing Computer Graphics: 3D models camera model (focuses

More information

### Review for Ray-tracing Algorithm and Hardware

Review for Ray-tracing Algorithm and Hardware Reporter: 邱敬捷博士候選人 Lan-Da Van ( 范倫達 ), Ph. D. Department of Computer Science National Chiao Tung University Taiwan, R.O.C. Summer, 2017 1 2017/7/26 Outline

More information

### Introduction Ray tracing basics Advanced topics (shading) Advanced topics (geometry) Graphics 2010/2011, 4th quarter. Lecture 11: Ray tracing

Lecture 11 Ray tracing Introduction Projection vs. ray tracing Projection Ray tracing Rendering Projection vs. ray tracing Projection Ray tracing Basic methods for image generation Major areas of computer

More information

### Geometric optics. The University of Texas at Austin CS384G Computer Graphics Don Fussell

Ray Tracing Geometric optics Modern theories of light treat it as both a wave and a particle. We will take a combined and somewhat simpler view of light the view of geometric optics. Here are the rules

More information

### Other Rendering Techniques CSE 872 Fall Intro You have seen Scanline converter (+z-buffer) Painter s algorithm Radiosity CSE 872 Fall

Other Rendering Techniques 1 Intro You have seen Scanline converter (+z-buffer) Painter s algorithm Radiosity 2 Intro Some more Raytracing Light maps Photon-map Reyes Shadow maps Sahdow volumes PRT BSSRF

More information

### Computer Graphics. Lecture 10. Global Illumination 1: Ray Tracing and Radiosity. Taku Komura 12/03/15

Computer Graphics Lecture 10 Global Illumination 1: Ray Tracing and Radiosity Taku Komura 1 Rendering techniques Can be classified as Local Illumination techniques Global Illumination techniques Local

More information

### Sung-Eui Yoon ( 윤성의 )

CS380: Computer Graphics Ray Tracing Sung-Eui Yoon ( 윤성의 ) Course URL: http://sglab.kaist.ac.kr/~sungeui/cg/ Class Objectives Understand overall algorithm of recursive ray tracing Ray generations Intersection

More information

### Computer Graphics. Si Lu. Fall uter_graphics.htm 11/22/2017

Computer Graphics Si Lu Fall 2017 http://web.cecs.pdx.edu/~lusi/cs447/cs447_547_comp uter_graphics.htm 11/22/2017 Last time o Splines 2 Today o Raytracing o Final Exam: 14:00-15:30, Novermber 29, 2017

More information

### Reading. Ray Tracing. Eye vs. light ray tracing. Geometric optics. Required: Watt, sections , (handout) Further reading:

Reading Required: Watt, sections 1.3-1.4, 12.1-12.5.1 (handout) Further reading: Ray Tracing T. Whitted. An improved illumination model for shaded display. Communications of the ACM 23(6), 343-349, 1980.

More information

### The Rasterization Pipeline

Lecture 5: The Rasterization Pipeline Computer Graphics and Imaging UC Berkeley CS184/284A, Spring 2016 What We ve Covered So Far z x y z x y (0, 0) (w, h) Position objects and the camera in the world

More information

### COMP371 COMPUTER GRAPHICS

COMP371 COMPUTER GRAPHICS SESSION 15 RAY TRACING 1 Announcements Programming Assignment 3 out today - overview @ end of the class Ray Tracing 2 Lecture Overview Review of last class Ray Tracing 3 Local

More information

### Computer Graphics and Image Processing Ray Tracing I

Computer Graphics and Image Processing Ray Tracing I Part 1 Lecture 9 1 Today s Outline Introduction to Ray Tracing Ray Casting Intersecting Rays with Primitives Intersecting Rays with Transformed Primitives

More information

### Consider a partially transparent object that is illuminated with two lights, one visible from each side of the object. Start with a ray from the eye

Ray Tracing What was the rendering equation? Motivate & list the terms. Relate the rendering equation to forward ray tracing. Why is forward ray tracing not good for image formation? What is the difference

More information

### Pipeline Operations. CS 4620 Lecture 10

Pipeline Operations CS 4620 Lecture 10 2008 Steve Marschner 1 Hidden surface elimination Goal is to figure out which color to make the pixels based on what s in front of what. Hidden surface elimination

More information

### Photorealism: Ray Tracing

Photorealism: Ray Tracing Reading Assignment: Chapter 13 Local vs. Global Illumination Local Illumination depends on local object and light sources only Global Illumination at a point can depend on any

More information

### Computer Graphics (CS 543) Lecture 13b Ray Tracing (Part 1) Prof Emmanuel Agu. Computer Science Dept. Worcester Polytechnic Institute (WPI)

Computer Graphics (CS 543) Lecture 13b Ray Tracing (Part 1) Prof Emmanuel Agu Computer Science Dept. Worcester Polytechnic Institute (WPI) Raytracing Global illumination-based rendering method Simulates

More information

### Reading. Ray Tracing. Eye vs. light ray tracing. Geometric optics. Required:

Reading Required: Watt, sections 1.3-1.4, 12.1-12.5.1 (handout) Triangle intersection handout Further reading: Ray Tracing Watt errata on syllabus page, needed if you work from his book instead of the

More information

### Rendering. Converting a 3D scene to a 2D image. Camera. Light. Rendering. View Plane

Rendering Pipeline Rendering Converting a 3D scene to a 2D image Rendering Light Camera 3D Model View Plane Rendering Converting a 3D scene to a 2D image Basic rendering tasks: Modeling: creating the world

More information

### Motivation. Sampling and Reconstruction of Visual Appearance. Effects needed for Realism. Ray Tracing. Outline

Sampling and Reconstruction of Visual Appearance CSE 274 [Fall 2018], Special Lecture Ray Tracing Ravi Ramamoorthi http://www.cs.ucsd.edu/~ravir Motivation Ray Tracing is a core aspect of both offline

More information

### Effects needed for Realism. Computer Graphics (Fall 2008) Ray Tracing. Ray Tracing: History. Outline

Computer Graphics (Fall 2008) COMS 4160, Lecture 15: Ray Tracing http://www.cs.columbia.edu/~cs4160 Effects needed for Realism (Soft) Shadows Reflections (Mirrors and Glossy) Transparency (Water, Glass)

More information

### Ray Tracing. CSCI 420 Computer Graphics Lecture 15. Ray Casting Shadow Rays Reflection and Transmission [Ch ]

CSCI 420 Computer Graphics Lecture 15 Ray Tracing Ray Casting Shadow Rays Reflection and Transmission [Ch. 13.2-13.3] Jernej Barbic University of Southern California 1 Local Illumination Object illuminations

More information

### SUMMARY. CS380: Introduction to Computer Graphics Ray tracing Chapter 20. Min H. Kim KAIST School of Computing 18/05/29. Modeling

CS380: Introduction to Computer Graphics Ray tracing Chapter 20 Min H. Kim KAIST School of Computing Modeling SUMMARY 2 1 Types of coordinate function Explicit function: Line example: Implicit function:

More information

### Lecture 17: Recursive Ray Tracing. Where is the way where light dwelleth? Job 38:19

Lecture 17: Recursive Ray Tracing Where is the way where light dwelleth? Job 38:19 1. Raster Graphics Typical graphics terminals today are raster displays. A raster display renders a picture scan line

More information

### Pipeline Operations. CS 4620 Lecture 14

Pipeline Operations CS 4620 Lecture 14 2014 Steve Marschner 1 Pipeline you are here APPLICATION COMMAND STREAM 3D transformations; shading VERTEX PROCESSING TRANSFORMED GEOMETRY conversion of primitives

More information

### So far, we have considered only local models of illumination; they only account for incident light coming directly from the light sources.

11 11.1 Basics So far, we have considered only local models of illumination; they only account for incident light coming directly from the light sources. Global models include incident light that arrives

More information

### Ray Tracing. Outline. Ray Tracing: History

Foundations of omputer Graphics Online Lecture 9: Ray Tracing 1 History and asic Ray asting Ravi Ramamoorthi Effects needed for Realism (Soft) Shadows Reflections (Mirrors and Glossy) Transparency (Water,

More information

### Lecture 10: Ray tracing

Interactive Computer Graphics Lecture 10: Ray tracing Graphics Lecture 10: Slide 1 Some slides adopted from H. Pfister, Harvard Graphics Lecture 10: Slide 2 Direct and Global Illumination Direct illumination:

More information

### Topics and things to know about them:

Practice Final CMSC 427 Distributed Tuesday, December 11, 2007 Review Session, Monday, December 17, 5:00pm, 4424 AV Williams Final: 10:30 AM Wednesday, December 19, 2007 General Guidelines: The final will

More information

### Lecture 11: Ray tracing (cont.)

Interactive Computer Graphics Ray tracing - Summary Lecture 11: Ray tracing (cont.) Graphics Lecture 10: Slide 1 Some slides adopted from H. Pfister, Harvard Graphics Lecture 10: Slide 2 Ray tracing -

More information

### Illumination Algorithms

Global Illumination Illumination Algorithms Digital Lighting and Rendering CGT 340 The goal of global illumination is to model all possible paths of light to the camera. Global Illumination Global illumination

More information

### Ray Tracing. Foley & Van Dam, Chapters 15 and 16

Ray Tracing Foley & Van Dam, Chapters 15 and 16 Ray Tracing Visible Surface Ray Tracing (Ray Casting) Examples Efficiency Issues Computing Boolean Set Operations Recursive Ray Tracing Determine visibility

More information

### Ray Tracing Foley & Van Dam, Chapters 15 and 16

Foley & Van Dam, Chapters 15 and 16 (Ray Casting) Examples Efficiency Issues Computing Boolean Set Operations Recursive Determine visibility of a surface by tracing rays of light from the viewer s eye

More information

### INFOGR Computer Graphics. J. Bikker - April-July Lecture 10: Ground Truth. Welcome!

INFOGR Computer Graphics J. Bikker - April-July 2015 - Lecture 10: Ground Truth Welcome! Today s Agenda: Limitations of Whitted-style Ray Tracing Monte Carlo Path Tracing INFOGR Lecture 10 Ground Truth

More information

### Supplement to Lecture 16

Supplement to Lecture 16 Global Illumination: View Dependent CS 354 Computer Graphics http://www.cs.utexas.edu/~bajaj/ Notes and figures from Ed Angel: Interactive Computer Graphics, 6 th Ed., 2012 Addison

More information

### Effects needed for Realism. Ray Tracing. Ray Tracing: History. Outline. Foundations of Computer Graphics (Spring 2012)

Foundations of omputer Graphics (Spring 202) S 84, Lecture 5: Ray Tracing http://inst.eecs.berkeley.edu/~cs84 Effects needed for Realism (Soft) Shadows Reflections (Mirrors and Glossy) Transparency (Water,

More information

### Computer Graphics. - Introduction to Ray Tracing - Philipp Slusallek

Computer Graphics - Introduction to Ray Tracing - Philipp Slusallek Rendering Algorithms Rendering Definition: Given a 3D scene as input and a camera, generate a 2D image as a view from the camera of the

More information

### Last week. Machiraju/Zhang/Möller

Last week Machiraju/Zhang/Möller 1 Overview of a graphics system Output device Input devices Image formed and stored in frame buffer Machiraju/Zhang/Möller 2 Introduction to CG Torsten Möller 3 Ray tracing:

More information

### CS-184: Computer Graphics. Administrative

CS-184: Computer Graphics Lecture #10: Raytracing Prof. James O Brien University of California, Berkeley V2005-10-1.1 Administrative Prof. O Brien away this Thursday and Friday Available after class today

More information

### Recollection. Models Pixels. Model transformation Viewport transformation Clipping Rasterization Texturing + Lights & shadows

Recollection Models Pixels Model transformation Viewport transformation Clipping Rasterization Texturing + Lights & shadows Can be computed in different stages 1 So far we came to Geometry model 3 Surface

More information

### Photorealistic 3D Rendering for VW in Mobile Devices

Abstract University of Arkansas CSCE Department Advanced Virtual Worlds Spring 2013 Photorealistic 3D Rendering for VW in Mobile Devices Rafael Aroxa In the past few years, the demand for high performance

More information

### Global Illumination. Why Global Illumination. Pros/Cons and Applications. What s Global Illumination

Global Illumination Why Global Illumination Last lecture Basic rendering concepts Primitive-based rendering Today: Global illumination Ray Tracing, and Radiosity (Light-based rendering) What s Global Illumination

More information

### Texture Mapping II. Light maps Environment Maps Projective Textures Bump Maps Displacement Maps Solid Textures Mipmaps Shadows 1. 7.

Texture Mapping II Light maps Environment Maps Projective Textures Bump Maps Displacement Maps Solid Textures Mipmaps Shadows 1 Light Maps Simulates the effect of a local light source + = Can be pre-computed

More information

### Assignment 6: Ray Tracing

Assignment 6: Ray Tracing Programming Lab Due: Monday, April 20 (midnight) 1 Introduction Throughout this semester you have written code that manipulated shapes and cameras to prepare a scene for rendering.

More information

### Computer Graphics 1. Chapter 7 (June 17th, 2010, 2-4pm): Shading and rendering. LMU München Medieninformatik Andreas Butz Computergraphik 1 SS2010

Computer Graphics 1 Chapter 7 (June 17th, 2010, 2-4pm): Shading and rendering 1 The 3D rendering pipeline (our version for this class) 3D models in model coordinates 3D models in world coordinates 2D Polygons

More information

### Enhancing Traditional Rasterization Graphics with Ray Tracing. October 2015

Enhancing Traditional Rasterization Graphics with Ray Tracing October 2015 James Rumble Developer Technology Engineer, PowerVR Graphics Overview Ray Tracing Fundamentals PowerVR Ray Tracing Pipeline Using

More information

### Recursive Ray Tracing. Ron Goldman Department of Computer Science Rice University

Recursive Ray Tracing Ron Goldman Department of Computer Science Rice University Setup 1. Eye Point 2. Viewing Screen 3. Light Sources 4. Objects in Scene a. Reflectivity b. Transparency c. Index of Refraction

More information

### Lecture 11. More Ray Casting/Tracing

Lecture 11 More Ray Casting/Tracing Basic Algorithm For each pixel { } Shoot a ray from camera to pixel for all objects in scene Compute intersection with ray Find object with closest intersection Display

More information

### CS 563 Advanced Topics in Computer Graphics Lecture 2: Bare-Bones Raytracer. by Emmanuel Agu

CS 563 Advanced Topics in Computer Graphics Lecture 2: Bare-Bones Raytracer by Emmanuel Agu Ray Casting (Appel, 1968) direct illumination Recursive ray tracing (Whitted, 1980) Pseudocode for Ray Tracer

More information

### Computer Graphics. Lecture 14 Bump-mapping, Global Illumination (1)

Computer Graphics Lecture 14 Bump-mapping, Global Illumination (1) Today - Bump mapping - Displacement mapping - Global Illumination Radiosity Bump Mapping - A method to increase the realism of 3D objects

More information

### Ray-Tracing. Misha Kazhdan

Ray-Tracing Misha Kazhdan Ray-Tracing In graphics, we often represent the surface of a 3D shape by a set of triangles. Goal: Ray-Tracing Take a collection of triangles representing a 3D scene and render

More information

### Luxo Jr. (Pixar, 1986) Last Time. Real Cameras and Ray Tracing. Standard Rasterization. Lights, Cameras, Surfaces. Now Playing:

Now Playing: Luxo Jr. (Pixar, 1986) Giant Steps From Giant Steps Recorded May 4-5, 1959 John Coltrane - Tenor Sax Tommy Flanagan - Piano Paul Chambers - Bass Art Taylor - Drums Real Cameras and Ray Tracing

More information

### CSE528 Computer Graphics: Theory, Algorithms, and Applications

CSE528 Computer Graphics: Theory, Algorithms, and Applications Hong Qin State University of New York at Stony Brook (Stony Brook University) Stony Brook, New York 11794--4400 Tel: (631)632-8450; Fax: (631)632-8334

More information

### Review. Stephen J. Guy

Review Stephen J. Guy Overview Pixar short Review last class Review course Area of Graphics Image Processing Rendering Modeling Animation Misc Area of Graphics Image Processing Rendering Modeling Animation

More information

### Shading, Advanced Rendering. Week 7, Wed Feb 28

University of British Columbia CPSC 314 Computer Graphics Jan-Apr 2007 Tamara Munzner Shading, Advanced Rendering Week 7, Wed Feb 28 http://www.ugrad.cs.ubc.ca/~cs314/vjan2007 Reading for Today and Tomorrow

More information

### Ray Tracing. CS334 Fall Daniel G. Aliaga Department of Computer Science Purdue University

Ray Tracing CS334 Fall 2013 Daniel G. Aliaga Department of Computer Science Purdue University Ray Casting and Ray Tracing Ray Casting Arthur Appel, started around 1968 Ray Tracing Turner Whitted, started

More information

### The Rendering Equation & Monte Carlo Ray Tracing

Last Time? Local Illumination & Monte Carlo Ray Tracing BRDF Ideal Diffuse Reflectance Ideal Specular Reflectance The Phong Model Radiosity Equation/Matrix Calculating the Form Factors Aj Ai Reading for

More information

### Lighting and Shading

Lighting and Shading Today: Local Illumination Solving the rendering equation is too expensive First do local illumination Then hack in reflections and shadows Local Shading: Notation light intensity in,

More information

### Real-Time Shadows. Last Time? Today. Why are Shadows Important? Shadows as a Depth Cue. For Intuition about Scene Lighting

Last Time? Real-Time Shadows Today Why are Shadows Important? Shadows & Soft Shadows in Ray Tracing Planar Shadows Projective Texture Shadows Shadow Maps Shadow Volumes Why are Shadows Important? Depth

More information

### Homework #2. Hidden Surfaces, Projections, Shading and Texture, Ray Tracing, and Parametric Curves

Computer Graphics Instructor: Brian Curless CSE 457 Spring 2013 Homework #2 Hidden Surfaces, Projections, Shading and Texture, Ray Tracing, and Parametric Curves Assigned: Sunday, May 12 th Due: Thursday,

More information

### Ray Tracing. Shandong University

Ray Tracing Shandong University Introduction OpenGL is based on a pipeline model in which primitives are rendered one at time - No shadows (except by tricks or multiple renderings) - No multiple reflections

More information

### The Traditional Graphics Pipeline

Last Time? The Traditional Graphics Pipeline Reading for Today A Practical Model for Subsurface Light Transport, Jensen, Marschner, Levoy, & Hanrahan, SIGGRAPH 2001 Participating Media Measuring BRDFs

More information

### graphics pipeline computer graphics graphics pipeline 2009 fabio pellacini 1

graphics pipeline computer graphics graphics pipeline 2009 fabio pellacini 1 graphics pipeline sequence of operations to generate an image using object-order processing primitives processed one-at-a-time

More information

### The Traditional Graphics Pipeline

Last Time? The Traditional Graphics Pipeline Participating Media Measuring BRDFs 3D Digitizing & Scattering BSSRDFs Monte Carlo Simulation Dipole Approximation Today Ray Casting / Tracing Advantages? Ray

More information

### For Intuition about Scene Lighting. Today. Limitations of Planar Shadows. Cast Shadows on Planar Surfaces. Shadow/View Duality.

Last Time Modeling Transformations Illumination (Shading) Real-Time Shadows Viewing Transformation (Perspective / Orthographic) Clipping Projection (to Screen Space) Graphics Pipeline Clipping Rasterization

More information

### Programming projects. Assignment 1: Basic ray tracer. Assignment 1: Basic ray tracer. Assignment 1: Basic ray tracer. Assignment 1: Basic ray tracer

Programming projects Rendering Algorithms Spring 2010 Matthias Zwicker Universität Bern Description of assignments on class webpage Use programming language and environment of your choice We recommend

More information

### graphics pipeline computer graphics graphics pipeline 2009 fabio pellacini 1

graphics pipeline computer graphics graphics pipeline 2009 fabio pellacini 1 graphics pipeline sequence of operations to generate an image using object-order processing primitives processed one-at-a-time

More information

### Ray Casting. Outline. Similar to glulookat derivation. Foundations of Computer Graphics

Foundations of omputer Graphics Online Lecture 10: Ray Tracing 2 Nuts and olts amera Ray asting Outline amera Ray asting (choose ray directions) Ravi Ramamoorthi Outline in ode Image Raytrace (amera cam,

More information

### Last Time? Ray Casting. Administrivia: Lab & Office Hours. Notes on Assignments. Ray Casting. Overview of Today

Ray Casting Last Time? Luxo Jr. Applications of Computer Graphics Overview of the semester IFS Assignment 0 due tomorrow @ 11:59pm Questions? 1 2 Notes on Assignments Make sure you turn in a linux or windows

More information

### Viewing and Ray Tracing. CS 4620 Lecture 4

Viewing and Ray Tracing CS 4620 Lecture 4 2014 Steve Marschner 1 Projection To render an image of a 3D scene, we project it onto a plane Most common projection type is perspective projection 2014 Steve

More information

### Computer Graphics. Lecture 02 Graphics Pipeline. Edirlei Soares de Lima.

Computer Graphics Lecture 02 Graphics Pipeline Edirlei Soares de Lima What is the graphics pipeline? The Graphics Pipeline is a special software/hardware subsystem

More information

### Point Cloud Filtering using Ray Casting by Eric Jensen 2012 The Basic Methodology

Point Cloud Filtering using Ray Casting by Eric Jensen 01 The Basic Methodology Ray tracing in standard graphics study is a method of following the path of a photon from the light source to the camera,

More information

### Chapter 7 - Light, Materials, Appearance

Chapter 7 - Light, Materials, Appearance Types of light in nature and in CG Shadows Using lights in CG Illumination models Textures and maps Procedural surface descriptions Literature: E. Angel/D. Shreiner,

More information

### Today. Rendering algorithms. Rendering algorithms. Images. Images. Rendering Algorithms. Course overview Organization Introduction to ray tracing

Today Rendering Algorithms Course overview Organization Introduction to ray tracing Spring 2010 Matthias Zwicker Universität Bern Rendering algorithms Problem statement Given computer representation of

More information

### Introduction to Ray-tracing Objectives

Introduction to Ray-tracing Objectives Define ray-tracing as a means of rendering Ray-tracing for spheres Combining with shading model An algorithm framework 2 1 Light vs. Rendering 3 (Local) Ray-tracing

More information

### The Traditional Graphics Pipeline

Final Projects Proposals due Thursday 4/8 Proposed project summary At least 3 related papers (read & summarized) Description of series of test cases Timeline & initial task assignment The Traditional Graphics

More information

### CHAPTER 1 Graphics Systems and Models 3

?????? 1 CHAPTER 1 Graphics Systems and Models 3 1.1 Applications of Computer Graphics 4 1.1.1 Display of Information............. 4 1.1.2 Design.................... 5 1.1.3 Simulation and Animation...........

More information

### A Little Background. Motivation. Motivation

A Little Background Ray casting Process of shooting rays into scene to get pixel colors Nonrecursive, i.e., no interreflections Origin: Arthur Appel, 1968 (earlier work by others for nonrendering) Ray

More information

### CS580: Ray Tracing. Sung-Eui Yoon ( 윤성의 ) Course URL:

CS580: Ray Tracing Sung-Eui Yoon ( 윤성의 ) Course URL: http://sglab.kaist.ac.kr/~sungeui/gcg/ Recursive Ray Casting Gained popularity in when Turner Whitted (1980) recognized that recursive ray casting could

More information

### Questions??? Announcements Assignment 3 due today

Announcements Assignment 3 due today Questions??? Remember that you have late days (if you haven t used them yet ) Problem set 3 out at the end of the day Movie for Assignment 2 at the end of class 1 Ray

More information

### Rendering Algorithms: Real-time indirect illumination. Spring 2010 Matthias Zwicker

Rendering Algorithms: Real-time indirect illumination Spring 2010 Matthias Zwicker Today Real-time indirect illumination Ray tracing vs. Rasterization Screen space techniques Visibility & shadows Instant

More information

### Ray tracing Tutorial. Lukas Herzberger

Ray tracing Tutorial Lukas Herzberger Agenda Ray tracing algorithm (lab 4a) Intersection tests Ray tracing algorithm (lab 4b) Hints & common mistakes Agenda Ray tracing algorithm (lab 4a) Intersection

More information

### Viewing and Ray Tracing

Viewing and Ray Tracing CS 4620 Lecture 4 2018 Steve Marschner 1 Projection To render an image of a 3D scene, we project it onto a plane Most common projection type is perspective projection 2018 Steve

More information

### Global Illumination CS334. Daniel G. Aliaga Department of Computer Science Purdue University

Global Illumination CS334 Daniel G. Aliaga Department of Computer Science Purdue University Recall: Lighting and Shading Light sources Point light Models an omnidirectional light source (e.g., a bulb)

More information

### Spring 2012 Final. CS184 - Foundations of Computer Graphics. University of California at Berkeley

Spring 2012 Final CS184 - Foundations of Computer Graphics University of California at Berkeley Write your name HERE: Write your login HERE: Closed book. You may not use any notes or printed/electronic

More information