This code can't actually be enabled for building and is incomplete, but it's
here because we know we want to support this at some point and there's not much
reason to have it in a separate branch if a simple #ifdef can disable it.
* Remove the compatible falloff SSS implementation. We shouldn't support two implementations in the long term, and 2.7x is a good release number do break some compatibility as well.
* Version patch added, so Files with Compatible falloff will automatically use Cubic now.
It was already mentioned in the manual, that Compatible is deprecated.
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/Shaders#BSSRDF
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.
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
for texture system in advance. Patch by Martijn Berger, with some tweaks.
There was about a 10% performance improvement on OS X in my tests with the
images.blend test file. This may be less on other platforms because OS X has
particularly slow mutex locks.
* 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.
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.
* 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).
and preview running at the same time.
It seems there's something in OSL/LLVM that's not thread safe, but I couldn't
figure out what exactly. Now all renders share the same OSL ShadingSystem which
should avoid the problem.
well as I would like, but it works, just add a subsurface scattering node and
you can use it like any other BSDF.
It is using fully raytraced sampling compatible with progressive rendering
and other more advanced rendering algorithms we might used in the future, and
it uses no extra memory so it's suitable for complex scenes.
Disadvantage is that it can be quite noisy and slow. Two limitations that will
be solved are that it does not work with bump mapping yet, and that the falloff
function used is a simple cubic function, it's not using the real BSSRDF
falloff function yet.
The node has a color input, along with a scattering radius for each RGB color
channel along with an overall scale factor for the radii.
There is also no GPU support yet, will test if I can get that working later.
Node Documentation:
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/Shaders#BSSRDF
Implementation notes:
http://wiki.blender.org/index.php/Dev:2.6/Source/Render/Cycles/Subsurface_Scattering
big lamps and sharp glossy reflections. This was already supported for mesh
lights and the background, so lamps should do it too.
This is not for free and it's a bit slower than I hoped even though there is
no extra BVH ray intersection. I'll try to optimize it more later.
* Area lights look a bit different now, they had the wrong shape before.
* Also fixes a sampling issue in the non-progressive integrator.
* Only enabled for the CPU, will test on the GPU later.
* An option to disable this will be added for situations where it does not help.
Same time comparison before/after:
http://www.pasteall.org/pic/show.php?id=43313http://www.pasteall.org/pic/show.php?id=43314
should be no functional changes yet. UV, tangent and intercept are now stored
as attributes, with the intention to add more like multiple uv's, vertex
colors, generated coordinates and motion vectors later.
Things got a bit messy due to having both triangle and curve data in the same
mesh data structure, which also gives us two sets of attributes. This will get
cleaned up when we split the mesh class.
a size parameter between 0.0 and 1.0 that gives a angle of reflection between
0° and 90°, and a smooth parameter that gives and angle over which a smooth
transition from full to no reflection happens.
These work with global illumination and do importance sampling of the area within
the angle. Note that unlike most other BSDF's these are not energy conserving in
general, in particular if their weight is 1.0 and size > 2/3 (or 60°) they will
add more energy in each bounce.
Diffuse: http://www.pasteall.org/pic/show.php?id=42119
Specular: http://www.pasteall.org/pic/show.php?id=42120
not properly optimized out in some cases.
For reference, setting this will give detailed information about OSL shaders:
export OSL_OPTIONS="statistics:level=1,debug=1,llvm_debug=1"
OSL noise() function is generating NaN's in certain cases, fix for that goes to our
OSL branch.
Also add missing minimum weight and max closure checks to OSL, forgot to add these
when fixing another bug.
Also some simple OSL optimization, passing thread data pointer directly instead
of via thread local storage, and creating ustrings for attribute lookup.
