Lighting: Dynamic Range
- the real world has much, much higher dynamic range than computers currently
allow
- it would be great to model the actual light values of each objects, in realistic
units, then dynamically map a clipped range of values onto the actually 0-255
range of the output display.
- this would allow for day/night rendering of emissive sources (sun, moon,
stars, streetlights etc.) in as realistic a fashion as possible
- this is still a new area of research
-
the
abbreviation is usually "HDR" or "HDRI" for High Dynamic Range Images
- Johan Hammes's
Dynamic Eye Modeling
- visual examples of his approach to the "glare" effect of the human eye's
reaction to light
- Gregory Ward Larson has done
tons of work in this field
- Paul Debevec has done lots
of work in this area
- many, many academic papers on HDR imaging
- HDR Shop is a program
for manipulating HDR images
- Jack Tumblin says "Computer
graphics rendering should mimic human vision, not film cameras; it should include
more of the light-dependent changes in the way we see."
-
HDRI & Luminance space is a overview and explanation in layman's terms
- consider that TV/Video material on CRTs has the same brightness range as
a computer screen, yet people find that level of realism convincing: with the
right combination of level balancing and tricks like lens flare, it is therefore
logically possible to reproduce the effect of that extra brightness without
actually emitting more photons.
-
OpenGL
1.2 added some interesting sounding imaging extensions which may provide some
hardware assistance for histogram functions
- Exposure
by Hugo Elias
- discusses the dynamic range problem by analogy to photography
- input from Deanan: "I've done some
10/12 bit stuff on the onyx which was really nice. It might be possible
to do some realtime histogram stuff but I've not timed how fast the OpenGL histogram
extensions are."
