* Henyey-Greenstein scattering closure implementation.
* Rename transparent to absorption node and isotropic to scatter node.
* Volume density is folded into the closure weights.
* OSL support for volume closures and nodes.
* This commit has no user visible changes, there is no volume render code yet.
This is work by "storm", Stuart Broadfoot, Thomas Dinges and myself.
A new hair bsdf node, with two closure options, is added. These closures allow the generation of the reflective and transmission components of hair. The node allows control of the highlight colour, roughness and angular shift.
Llimitations include:
-No glint or fresnel adjustments.
-The 'offset' is un-used when triangle primitives are used.
give a result more similar to the Compatible falloff option. The scale is x2
though to keep the perceived scatter radius roughly the same while changing the
sharpness. Difference with compatible will be mainly on non-flat geometry.
* Added a new sky model by Hosek and Wilkie: "An Analytic Model for Full Spectral Sky-Dome Radiance" http://cgg.mff.cuni.cz/projects/SkylightModelling/
Example render:
http://archive.dingto.org/2013/blender/code/new_sky_model.png
Documentation:
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/Textures#Sky_Texture
Details:
* User can choose between the older Preetham and the new Hosek / Wilkie model via a dropdown. For older files, backwards compatibility is preserved. When we add a new Sky texture, it defaults to the new model though.
* For the new model, you can specify the ground albedo (see documentation for details).
* Turbidity now has a UI soft range between 1 and 10, higher values (up to 30) are still possible, but can result in weird colors or black.
* Removed the limitation of 1 sky texture per SVM stack. (Patch by Lukas Tönne, thanks!)
Thanks to Brecht for code review and some help!
This is part of my GSoC 2013 project, SVN merge of r59214, r59220, r59251 and r59601.
* OSL rendered Black with Compatible Fallof option, fixed.
Note: OSL uses compatible scattering when "Compatible" or "Bicubic" is selected. I guess compatible will be removed later? If not we need to fix this properly.
New features:
* Bump mapping now works with SSS
* Texture Blur factor for SSS, see the documentation for details:
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/Shaders#Subsurface_Scattering
Work in progress for feedback:
Initial implementation of the "BSSRDF Importance Sampling" paper, which uses
a different importance sampling method. It gives better quality results in
many ways, with the availability of both Cubic and Gaussian falloff functions,
but also tends to be more noisy when using the progressive integrator and does
not give great results with some geometry. It works quite well for the
non-progressive integrator and is often less noisy there.
This code may still change a lot, so unless you're testing it may be best to
stick to the Compatible falloff function.
Skin test render and file that takes advantage of the gaussian falloff:
http://www.pasteall.org/pic/show.php?id=57661http://www.pasteall.org/pic/show.php?id=57662http://www.pasteall.org/blend/23501
* Remove code for the unused Wave texture variations.
We have quite some unused code in the texture area, I guess it doesn't harm to clean a bit up here.
We can always get the code back from SVN if we need something.
* Added a node to convert a temperature in Kelvin to an RGB color. This can be used e.g. for lights, to easily find the right color temperature.
= Some common temperatures =
Candle light: 1500 Kelvin
Sunset/Sunrise: 1850 Kelvin
Studio lamps: 3200 Kelvin
Horizon daylight: 5000 Kelvin
Documentation: http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/More#Blackbody
Thanks to Philipp Oeser (lichtwerk), who essentially contributed to this with a patch! :)
This is part of my GSoC 2013 project. SVN merge of r57424, r57487, r57507, r57525, r58253 and r58774
* Added a Ray Depth output to the Light Path node, which gives the user access to the current bounce.
This can be used to limit the maximum ray bounce on a per shader basis. Another use case is to restrict light influence with this, to have a lamp only contribute to the direct lighting.
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/More#Light_Path
This is part of my GSoC 2013 project. SVN merge of r58091 and r58772 from soc-2013-dingto.
* Reshuffle SSE #ifdefs to try to avoid compilation errors enabling SSE on 32 bit.
* Remove CUDA kernel launch size exception on Mac, is not needed.
* Make OSL file compilation quiet like c/cpp files.
* First (brute force) implementation for SVM. This works and delivers the same result as OSL, but it's slow.
* Code inside svm_blackbody.h inspired by a patch by Philipp Oeser (#35698), thanks.
Ideas:
* Use a lookup table to perform the calculations on render/ level.
* Implement it as a RNA property only, and do the calculation like Sun/Sky precompute.
* Added a node to convert wavelength (in nanometers, from 380nm to 780nm) to RGB values. This can be useful to match real world colors easier.
* Code cleanup:
** Moved color functions (xyz and hsv) into dedicated utility files.
** Remove svm_lerp(), use interp() instead.
Documentation:
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/More#Wavelength
Example render:
http://www.pasteall.org/pic/show.php?id=53202
This is part of my GSoC 2013. (revisions 57322, 57326, 57335 and 57367 from soc-2013-dingto).
to be done in cycles itself to keep compatibility for bytecode too.
Also fix broken button to compile OSL from the text editors, this got broken after
recent change to disable editing of library linked nodes.
* Move hsv and xyz color functions into the dedicated util files (util_color.h and node_color.h).
* svm_lerp moved into util_math.h and renamed to lerp_interp, as it's used for the wavelength node now as well.
* Added a node to convert wavelength (in nanometer, from 380nm to 780nm) to RGB values. This can be useful to match real world colors easier.
Example render:
http://www.pasteall.org/pic/show.php?id=53202
ToDo:
* Move some functions into an util file, maybe a common util_color.h or so.
* Test GPU, unfortunately sm_21 doesn't work for me yet.
* Rename fresnel_dielectric() to fresnel_dielectric_cos() to match SVM, easier when searching code.
* Also remove an old code comment in bsdf_reflection.h from Cycles branch days.
* Added Westin Sheen and Westin Backscatter closures for testing, useful for Cloth like effects.
Only available via OSL, added an example OSL shader to the Templates (Text Editor).
