Blender Git Commit Log

Git Commits -> Revision ed5dbb0

Revision ed5dbb0 by Sergey Sharybin (master)
December 5, 2015, 20:21 (GMT)
Cycles: Implement extrapolation for RGB curves

Previously RGB Curves node will clamp input to 0..1 which is rather useless
when one wants to use HDR image textures and do bit of correction on them.

Now kernel code supports extrapolation of baked LUT based on first/last two
table points and performs linear extrapolation.

The only tricky part is to guess the range to bake the LUT for. Currently
it's using simple approach -- minmax of the input curves. While this behaves
ok for the simple cases it's easy to trick the system up causing incorrect
results.

Not sure we can solve those issues in a general case and since the new code
is giving more expected results it's not that bad actually. In the worst
case artist migh always create explicit point to make sure LUT is created
for the needed HDR range.

Reviewers: brecht, juicyfruit

Subscribers: sebastian_k

Differential Revision: https://developer.blender.org/D1658

Commit Details:

Full Hash: ed5dbb0a7b2bc7bef3776d31eaf466ec8740560f
Parent Commit: 258564a
Lines Changed: +125, -19

6 Modified Paths:

/intern/cycles/blender/blender_shader.cpp (+6, -1) (Diff)
/intern/cycles/blender/blender_util.h (+47, -3) (Diff)
/intern/cycles/kernel/shaders/node_rgb_curves.osl (+22, -3) (Diff)
/intern/cycles/kernel/svm/svm_ramp.h (+38, -11) (Diff)
/intern/cycles/render/nodes.cpp (+11, -1) (Diff)
/intern/cycles/render/nodes.h (+1, -0) (Diff)
By: Miika HämäläinenLast update: Nov-07-2014 14:18MiikaHweb | 2003-2021