blender/intern/cycles
Sv. Lockal 7201f6d14c Cycles: Use curve approximation for blackbody instead of lookup table
Now we calculate color in range 800..12000 using an approximation a/x+bx+c for R and G and ((at + b)t + c)t + d) for B.
Max absolute error for RGB for non-lut function is less than 0.0001, which is enough to get the same 8 bit/channel color as for OSL with a noticeable performance difference.
However there is a slight visible difference between previous non-OSL implementation because of lookup table interpolation and offset-by-one mistake.
The previous implementation gave black color outside of soft range (t > 12000), now it gives the same color as for 12000.

Also blackbody node without input connected is being converted to value input at shader compile time.

Reviewers: dingto, sergey

Reviewed By: dingto

Subscribers: nutel, brecht, juicyfruit

Differential Revision: https://developer.blender.org/D1280
2015-05-05 06:11:54 +00:00
..
app Cycles: Fix copy / paste mistake in XML reader. 2015-05-04 14:31:20 +02:00
blender Separate scene simplification into viewport and render 2015-05-04 16:31:10 +05:00
bvh Cleanup: style & const's 2015-05-05 05:19:49 +10:00
cmake Cycles: Post-reintegration tweaks to ensure things do compile 2015-01-01 01:31:08 +05:00
device Cycles: Fix compilation error on windows after recent logging changes 2015-04-10 22:35:10 +05:00
doc Cycles: relicense GNU GPL source code to Apache version 2.0. 2013-08-18 14:16:15 +00:00
kernel Cycles: Use curve approximation for blackbody instead of lookup table 2015-05-05 06:11:54 +00:00
render Cycles: Use curve approximation for blackbody instead of lookup table 2015-05-05 06:11:54 +00:00
subd Cycles: Code cleanup, spaces around keywords 2015-03-28 00:15:15 +05:00
util Fix T44548: Cycles Tube Mapping off / not compatible with BI 2015-04-30 14:27:16 +05:00
CMakeLists.txt Optionally use c++11 stuff instead of boost in cycles where possible. We do and continue to depend on boost though 2015-03-29 22:12:40 +02:00
SConscript Optionally use c++11 stuff instead of boost in cycles where possible. We do and continue to depend on boost though 2015-03-29 22:12:40 +02:00