SIGGRAPH 2003 Course #19 HDRI and Image-Based Lighting HDRI and - PDF document

SIGGRAPH 2003 Course #19 HDRI and Image-Based Lighting HDRI and Image-Based Lighting HDRI and Image-Based Lighting SIGGRAPH 2003 Course #19 SIGGRAPH 2003 Course #19 Greg Ward Rod Bogart Greg Ward Rod Bogart Anyhere Software Anyhere Software Industrial Light and Magic Industrial Light and Magic What is Image-Based Lighting? What is Image-Based Lighting? Paul Debevec Paul Debevec Frank Vitz Frank Vitz USC ICT Independent VFX USC ICT Independent VFX Supervisor Supervisor Monday, July 28, 2003 Monday, July 28, 2003 10:30-12:15 and 6:00-8:00 10:30-12:15 and 6:00-8:00 www.debevec.org/IBL2003 www.debevec.org/IBL2003 Real-World HDR Lighting Environments Funston Eucalyptus Beach Grove Grace Uffizi Cathedral Gallery Lighting Environments from the Light Probe Image Gallery: Lighting Environments from the Light Probe Image Gallery: http://www.debevec.org/Probes/ http://www.debevec.org/Probes/ Illuminating Objects using Illuminating Objects using Measurements of Real Light Measurements of Real Light Environment Environment Light Light assigned “glow” assigned “glow” material material property in property in Greg Larson’s Greg Larson’s RADIANCE RADIANCE Object Object system. system. http://radsite.lbl.gov/radiance/ http://radsite.lbl.gov/radiance/ Paul Debevec / USC ICT / www.debevec.org/IBL2003/ Page 1

SIGGRAPH 2003 Course #19 HDRI and Image-Based Lighting Panoramic (Omnidirectional) Panoramic (Omnidirectional) Photography Photography High-Dynamic Range Photography High-Dynamic Range Photography 300,000 : 1 300,000 : 1 Visualization: Greg Ward Debevec and Malik, SIGGRAPH 97 Global Illumination Course Schedule Course Schedule Part I: Fundamentals of HDR and IBL Part I: Fundamentals of HDR and IBL 10:30 Introduction 10:30 Introduction 10:40 Ward 10:40 Ward - Global illumination overview - Global illumination overview - HDR Image Formats - HDR Image Formats - HDR Image Display - HDR Image Display 11:20 11:20 Paul Debevec Paul Debevec - Capturing real-world illumination - Capturing real-world illumination - Illuminating synthetic objects with real light - Illuminating synthetic objects with real light - Rendering synthetic objects into real scenes - Rendering synthetic objects into real scenes - Making “RNL” and “Fiat Lux” - Making “RNL” and “Fiat Lux” 12:15 Lunch 12:15 Lunch Resume at 6pm – same room Resume at 6pm – same room Arnold Rendering Part II: HDR & IBL in Production and Part II: HDR & IBL in Production and Advanced Techniques Advanced Techniques 6:05 Bogart 6:05 Bogart Global Illumination and High Global Illumination and High - HDR and IBL at Industrial Light + Magic - HDR and IBL at Industrial Light + Magic 6:35 Debevec 6:35 Debevec Dynamic Range Image File Formats Dynamic Range Image File Formats - Capturing Light Probes in the Sun - Capturing Light Probes in the Sun - HDRI and IBL at WETA (from Dan Lemmon) - HDRI and IBL at WETA (from Dan Lemmon) 6:55 Vitz 6:55 Vitz - HDRI and IBL for X-Men 2 - HDRI and IBL for X-Men 2 Greg Ward Greg Ward 7:25 Debevec 7:25 Debevec Anyhere Software Anyhere Software - Image Based Lighting Real-World Subjects - Image Based Lighting Real-World Subjects Light Stage 1, 2, and 3 Light Stage 1, 2, and 3 7:45 Q&A 7:45 Q&A - Bogart, Ward, Debevec, and Vitz - Bogart, Ward, Debevec, and Vitz 8:00 End 8:00 End Paul Debevec / USC ICT / www.debevec.org/IBL2003/ Page 2

SIGGRAPH 2003 Course #19 HDRI and Image-Based Lighting Dynamic Range in the Dynamic Range in the Real World Real World 1 Capturing Real-World The real world is Capturing Real-World high dynamic range. Illumination Illumination 1500 Paul Debevec Paul Debevec 25,000 USC ICT USC ICT 400,000 2,000,000,000 High-Dynamic Range Photography High-Dynamic Range Photography www.debevec.org/HDRShop 300,000 : 1 300,000 : 1 Visualization: Greg Ward Debevec and Malik, “Recovering High Dynamic Range Radiance Maps from Photographs”, SIGGRAPH 97 Chris Tchou et al. HDR Shop . S2001 Technical Sketch Methods for taking Methods for taking Ways to vary exposure Ways to vary exposure omnidirectional HDR images omnidirectional HDR images � Shutter Speed (*) � Shutter Speed (*) � Mirrored ball + camera � Mirrored ball + camera � Fisheye lens images � Fisheye lens images � F/stop (aperture, iris) � F/stop (aperture, iris) � Panoramic camera � Panoramic camera � Neutral Density (ND) Filters � Stitching images together � Stitching images together � Neutral Density (ND) Filters Paul Debevec / USC ICT / www.debevec.org/IBL2003/ Page 3

SIGGRAPH 2003 Course #19 HDRI and Image-Based Lighting Reflection Mapping - 1982 Reflection Mapping - 1982 Mike Chou and Lance Williams Mike Chou and Lance Williams Gene Miller and Ken Perlin Gene Miller and Ken Perlin Today: can perform in real time with graphics hardware Today: can perform in real time with graphics hardware http://www.debevec.org/ReflectionMapping/ http://www.debevec.org/ReflectionMapping/ Sources of Mirrored Balls Sources of Mirrored Balls 0.34 0.34 � 2-inch chrome balls ~ $20 ea. � 2-inch chrome balls ~ $20 ea. � McMaster-Carr Supply Company � McMaster-Carr Supply Company 59% Reflective 59% Reflective www.mcmaster.com www.mcmaster.com � 6-12 inch large gazing balls � 6-12 inch large gazing balls � Baker’s Lawn Ornaments � Baker’s Lawn Ornaments www.bakerslawnorn.com www.bakerslawnorn.com Need to Measure Need to Measure � Hollow Spheres, 2in – 4in � Hollow Spheres, 2in – 4in Mirrored Sphere Mirrored Sphere 0.58 � Dube Juggling Equipment 0.58 � Dube Juggling Equipment www.dube.com www.dube.com Reflectivity Reflectivity � FAQ on www.debevec.org/HDRShop � FAQ on www.debevec.org/HDRShop Fisheye Images Fisheye Images Fisheye Lens Radial Fisheye Lens Radial Falloff Falloff Paul Debevec / USC ICT / www.debevec.org/IBL2003/ Page 4

SIGGRAPH 2003 Course #19 HDRI and Image-Based Lighting Stitching HDRI with Realviz Stitching HDRI with Realviz Scanning Panoramic Scanning Panoramic Stitcher Stitcher Cameras Cameras http://www.gregdowning.com/HDRI/stitched/ Pros: Pros: very high res (10K x 7K+) very high res (10K x 7K+) Full sphere in one scan – no stitching Full sphere in one scan – no stitching Good dynamic range, some are HDR Good dynamic range, some are HDR Issues: Issues: More expensive More expensive Scans take a while Scans take a while Companies: Panoscan, Sphereon Companies: Panoscan, Sphereon (SIGGRAPH 2003 booth #3340) (SIGGRAPH 2003 booth #3340) See also www.kaidan.com Stitching HDRI with Realviz Stitching HDRI with Realviz Types of Omnidirectional Images Types of Omnidirectional Images Stitcher Stitcher http://www.gregdowning.com/HDRI/stitched/ Latitude/Longitude Cube Map Paul Debevec / USC ICT / www.debevec.org/IBL2003/ Page 5

SIGGRAPH 2003 Course #19 HDRI and Image-Based Lighting Types of Omnidirectional Types of Omnidirectional Images Images Illuminating Synthetic Objects Illuminating Synthetic Objects with Real Light with Real Light Mirrored Ball Angular Map IBL in Radiance IBL in Radiance Tutorial Tutorial In Jan/Feb 2002 In Jan/Feb 2002 Computer Graphics Computer Graphics and Applications and Applications and the SIGGRAPH and the SIGGRAPH 2003 IBL Course 2003 IBL Course Notes Notes and and www.debevec.org www.debevec.org under “Publications” under “Publications” Paul Debevec. A Tutorial on Image-Based Lighting. IEEE Computer Graphics and Applications, Jan/Feb 2002. Putting the probe onto the Light Probe Coordinate Mapping sphere {angmap.cal Convert from directions in the world to # Lighting Environment coordinates on the angular sphere image # specify the probe image and how it is mapped onto # geometry -z is forward (outer edge of sphere) +z is backward (center of sphere) void colorpict hdr_env +y is up (toward top of sphere)} 7 red green blue rnl_probe.hdr angmap.cal u v 0 norm = 1/sqrt(Py*Py + Px*Px + Pz*Pz); 0 DDy = Py*norm; DDx = Px*norm; # specify a "glow" material that will use this image hdr_env glow DDz = Pz*norm; env_glow 0 0 4 1 1 1 0 r = 0.159154943*acos(DDz)/sqrt(DDx*DDx + DDy*DDy); # specify a large inward-pointing box for the HDR envir. u = 0.5 + DDx * r; !genbox env_glow box 500 500 500 -i | xform -t -250 -18 -250 v = 0.5 + DDy * r; Paul Debevec / USC ICT / www.debevec.org/IBL2003/ Page 6

SIGGRAPH 2003 Course #19 HDRI and Image-Based Lighting Making Making Illuminating Objects using Illuminating Objects using Rendering with Natural Rendering with Natural Measurements of Real Light Measurements of Real Light Light Light Environment Environment Light Light assigned “glow” assigned “glow” material material property in property in Greg Larson’s Greg Larson’s RADIANCE RADIANCE Object Object system. system. http://radsite.lbl.gov/radiance/ http://radsite.lbl.gov/radiance/ SIGGRAPH 98 Electronic Theater See also: Larson and Shakespeare, “Rendering with Radiance”, 1998 See also: Larson and Shakespeare, “Rendering with Radiance”, 1998 Acquiring the Light Probe Assembling the Light Probe Acquiring the Light Probe Assembling the Light Probe RNL Environment mapped onto interior of large cube Paul Debevec / USC ICT / www.debevec.org/IBL2003/ Page 7