diff options
author | Ton Roosendaal <ton@blender.org> | 2003-12-30 21:03:37 +0300 |
---|---|---|
committer | Ton Roosendaal <ton@blender.org> | 2003-12-30 21:03:37 +0300 |
commit | d8b21b01c38bf2b7007458c221b2c1685d766cfd (patch) | |
tree | d4001fd3c914f10602ec095341307f64569a4941 /source/blender/makesdna | |
parent | 6c80064ab7e0ea1e5ec9b5a164db08497a94ccf4 (diff) |
Added improved exposure calculation
- based at 1.0-exp(-color) trick in Yafray. But to guarantee backwards
compatibility, and some more control, Stefano Selleri hacked a useful
formula for it.
- We now have 2 values to set:
- "exp": the exponential correction value (0-1)
- "range": the light range that maps on color 1.0 (0-5)
- Using exp(x) (is e^x) we can much better prevent overflows from render,
which are currently hard-clipped in Blender. Setting a small 'exp' value
wil efficiently smooth out high energy and map that back to a color for
display.
- total formula:
newcol= linfac*(1.0-exp(col*logfac))
col, newcol are colors
linfac= 1.0 + 1.0/((2.0*wrld.exp +0.5)^10)
logfac= log( (linfac-1.0)/linfac )/wrld.range
wrld.exp and wrld.range are the button values
- default setting: exp=0.0 and range=1.0 give results extremely close to
previous rendering.
- graph: http://www.selleri.org/Blender/buffer/Image1.png for 'exp' setting
ranging from 0-1, and with 'range'=2
Thanks Stefano for the help!
Diffstat (limited to 'source/blender/makesdna')
-rw-r--r-- | source/blender/makesdna/DNA_world_types.h | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/source/blender/makesdna/DNA_world_types.h b/source/blender/makesdna/DNA_world_types.h index 91e205e4038..fd367369bd5 100644 --- a/source/blender/makesdna/DNA_world_types.h +++ b/source/blender/makesdna/DNA_world_types.h @@ -56,8 +56,13 @@ typedef struct World { float ambr, ambg, ambb, ambk; unsigned int fastcol; - - float exposure; + + /** + * New exposure/range control. linfac & logfac are constants... don't belong in + * file, but allocating 8 bytes for temp mem isnt useful either. + */ + float exposure, range; + float linfac, logfac; /** * Gravitation constant for the game world @@ -87,7 +92,6 @@ typedef struct World { short dofsta, dofend, dofmin, dofmax; - int pad1; struct Ipo *ipo; struct MTex *mtex[8]; |