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/blenkernel/intern/world.c | |
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/blenkernel/intern/world.c')
-rw-r--r-- | source/blender/blenkernel/intern/world.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/source/blender/blenkernel/intern/world.c b/source/blender/blenkernel/intern/world.c index b482140e373..ea4f9bd790b 100644 --- a/source/blender/blenkernel/intern/world.c +++ b/source/blender/blenkernel/intern/world.c @@ -86,11 +86,13 @@ World *add_world(char *name) wrld->horb= 0.6f; wrld->skytype= WO_SKYBLEND; - wrld->exposure= 1.0f; wrld->stardist= 15.0f; wrld->starsize= 2.0f; wrld->gravity= 9.8f; - + + wrld->exposure= 0.0f; + wrld->range= 1.0f; + return wrld; } @@ -199,6 +201,10 @@ void init_render_world() } else { memset(&R.wrld, 0, sizeof(World)); - R.wrld.exposure= 1.0; + R.wrld.exposure= 0.0; + R.wrld.range= 1.0; } + + R.wrld.linfac= 1.0 + pow((2.0*R.wrld.exposure + 0.5), -10); + R.wrld.logfac= log( (R.wrld.linfac-1.0)/R.wrld.linfac )/R.wrld.range; } |