Brightness/Contrast Node for Cycles

Contrast helps to adjust IBL (HDR images used for background lighting).

A question, should we call it Bright (as we are doing in composite) or Brightness in the UI? So far this patch is calling Bright.

committed on rev. 43666

[zanqdo_gmail.com, 2012-01-23 02:32:43]

Perfect! thanks for this

straight HDRi
http://www.pasteall.org/pic/show.php?id=24932

slightly contrasted HDRi
http://www.pasteall.org/pic/show.php?id=24933

Daniel Salazar
patazstudio.com



On Sun, Jan 22, 2012 at 8:21 PM,  <dfelinto@gmail.com> wrote:
> Reviewers: bf-codereview_blender.org, brechtvl,
>
> Description:
> Contrast helps to adjust IBL (HDR images used for background lighting).
>
> A question, should we call it Bright (as we are doing in composite) or
> Brightness in the UI? So far this patch is calling Bright.
>
> Please review this at http://codereview.appspot.com/5564044/
>
> Affected files:
>   intern/cycles/app/cycles_xml.cpp
>   intern/cycles/blender/blender_shader.cpp
>   intern/cycles/kernel/CMakeLists.txt
>   intern/cycles/kernel/osl/nodes/CMakeLists.txt
>   intern/cycles/kernel/osl/nodes/node_brightness.osl
>   intern/cycles/kernel/svm/svm.h
>   intern/cycles/kernel/svm/svm_brightness.h
>   intern/cycles/kernel/svm/svm_types.h
>   intern/cycles/render/nodes.cpp
>   intern/cycles/render/nodes.h
>   source/blender/blenkernel/BKE_node.h
>   source/blender/blenkernel/intern/node.c
>   source/blender/makesrna/intern/rna_nodetree_types.h
>   source/blender/nodes/CMakeLists.txt
>   source/blender/nodes/NOD_shader.h
>   source/blender/nodes/shader/nodes/node_shader_brightness.c
>   source/blender/nodes/shader/nodes/node_shader_gamma.c
>
>
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> Bf-codereview mailing list
> Bf-codereview@blender.org
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[brechtvl, 2012-01-23 16:24:25]

http://codereview.appspot.com/5564044/diff/1/intern/cycles/kernel/svm/svm_bri...
File intern/cycles/kernel/svm/svm_brightness.h (right):

http://codereview.appspot.com/5564044/diff/1/intern/cycles/kernel/svm/svm_bri...
intern/cycles/kernel/svm/svm_brightness.h:30: brightness /= 100.0;
Add f postfix so we're not doing doubles math. Also *= 1.0f/100.0f; here and the
line below is a bit quicker.

http://codereview.appspot.com/5564044/diff/1/intern/cycles/kernel/svm/svm_bri...
intern/cycles/kernel/svm/svm_brightness.h:41: a = 1.0 / a;
Setting contrast to 100 will give division by zero here, needs check.

[dfelinto, 2012-01-23 18:12:27]

I added float postfix in all the code. comments coming next

[dfelinto, 2012-01-23 18:14:41]

Brecht, I added the float postfix everywhere (OSL included).

I have a feeling we may be able to get another bright contrast algorithm later.
This one came from Blender which came from opencv. It works fine but I wonder
what gimp is doing for example.

[brechtvl, 2012-01-24 12:27:49]

OSL should not have f postfix, but otherwise LGTM.