Blender Git Commit Log

Git Commits -> Revision 7201f6d

Revision 7201f6d by Sv. Lockal (master)
May 5, 2015, 06:11 (GMT)
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

Commit Details:

Full Hash: 7201f6d14c0161ad9a0d4143d1c5caf872e0d93e
Parent Commit: 22bbd1c
Lines Changed: +76, -258

By: Miika HämäläinenLast update: Nov-07-2014 14:18 MiikaHweb | 2003-2020