17_shadows

17_shadows - Real-Time Shadows MIT EECS 6.837, Durand and...

Info iconThis preview shows pages 1–20. Sign up to view the full content.

View Full Document Right Arrow Icon
MIT EECS 6.837, Durand and Cutler Real-Time Shadows
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
MIT EECS 6.837, Durand and Cutler Last Time? • The graphics pipeline • Visibility — the depth buffer (z-buffer)
Background image of page 2
MIT EECS 6.837, Durand and Cutler Schedule • Quiz 2: Thursday November 20 th , in class (two weeks from Thursday) • Project Presentations (to staff): December 1 st -5 th (~ 4 weeks) • Project Report due: Tuesday December 9 th (5 weeks from today)
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
MIT EECS 6.837, Durand and Cutler Questions?
Background image of page 4
MIT EECS 6.837, Durand and Cutler Today Why are Shadows Important? • Planar Shadows • Shadow Maps • Shadow Volumes
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
MIT EECS 6.837, Durand and Cutler Why are Shadows Important? • Depth cue •S c en e Lighting • Realism
Background image of page 6
MIT EECS 6.837, Durand and Cutler Shadows as a Depth Cue
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
MIT EECS 6.837, Durand and Cutler For Intuition about Scene Lighting • Position of the light (e.g. sundial) • Hard shadows vs. soft shadows • Colored lights • Directional light vs. point light
Background image of page 8
MIT EECS 6.837, Durand and Cutler Today • Why are Shadows Important? • Planar Shadows • Shadow Maps • Shadow Volumes
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
MIT EECS 6.837, Durand and Cutler Shadows • One shadow ray per intersection per point light source no shadow rays one shadow ray
Background image of page 10
MIT EECS 6.837, Durand and Cutler Soft Shadows • Caused by extended light sources • Umbra – source completely occluded • Penumbra – Source partially occluded • Fully lit Image removed due to copyright considerations.
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
MIT EECS 6.837, Durand and Cutler Soft Shadows • Multiple shadow rays to sample area light source one shadow ray lots of shadow rays
Background image of page 12
MIT EECS 6.837, Durand and Cutler Shadows in Ray Tracing • Shoot ray from visible point to light source • If blocked, discard light contribution • Optimization? – Stop after first intersection (don’t worry about tmin) – Coherence: remember the previous occluder, and test that object first
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
MIT EECS 6.837, Durand and Cutler Traditional Ray Tracing
Background image of page 14
MIT EECS 6.837, Durand and Cutler Ray Tracing + Soft Shadows
Background image of page 15

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
MIT EECS 6.837, Durand and Cutler Today • Why are Shadows Important? Planar Shadows • Shadow Maps • Shadow Volumes
Background image of page 16
MIT EECS 6.837, Durand and Cutler Cast Shadows on Planar Surfaces • Draw the object primitives a second time, projected to the ground plane
Background image of page 17

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
MIT EECS 6.837, Durand and Cutler Limitations of Planar Shadows • Does not produce self-shadows, shadows cast on other objects, shadows on curved surfaces, etc.
Background image of page 18