This solves bugs like T42210 which are caused by compiler being
smart and using some SSE instructions to operate with closure
classes, which was failing because those classes are not allocated
by the regular allocator but allocated in memory pool in OSL.
With newer versions of OSL it is now possible to force closure
classes being aligned to a given boundary and this commit uses
this new functionality.
Unfortunately, it means we're no longer compatible with older
versions of OSL, only latest git version from upstream and our
branch at github are supported:
https://github.com/Nazg-Gul/OpenShadingLanguage/tree/blender-fixes
For OSX and Windows it's not an issue because libraries are
already updated there, Linux users would need to run install_deps
script.
Was hooked up last year for testing purposes, as we already had some code for it, but the closure itself is not really good nor really useful, so let's remove it.
It turns out that the new Beckmann sampling function doesn't work well with
Quasi Monte Carlo sampling, mainly near normal incidence where it can be worse
than the previous sampler. In the new sampler the random number pattern gets
split in two, warped and overlapped, which hurts the stratification, see the
visualization in the differential revision.
Now we use a precomputed table, which is much better behaved. GGX does not seem
to benefit from using a precomputed table.
Disadvantage is that this table adds 1MB of memory usage and 0.03s startup time
to every render (on my quad core CPU).
Differential Revision: https://developer.blender.org/D614
* Anisotropic BSDF now supports GGX and Beckmann distributions, Ward has been
removed because other distributions are superior.
* GGX is now the default distribution for all glossy and anisotropic nodes,
since it looks good, has low noise and is fast to evaluate.
* Ashikhmin-Shirley is now available in the Glossy BSDF.
* Ashikhmin-Shirley anisotropic BSDF was added as closure
* Anisotropic BSDF node now has two distributions
Reviewers: brecht, dingto
Differential Revision: https://developer.blender.org/D549
* 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.
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
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).
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
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
Also some simple OSL optimization, passing thread data pointer directly instead
of via thread local storage, and creating ustrings for attribute lookup.
transmission pass and filter glossy option.
The BSDF closure class is now more similar to the SVM closures, and includes
some flags and labels that are needed to properly categorize the BSDF's for
render passes. Phong closure is gone for the moment, needs to be adapated to
the new structure still.
* Added the Phong BRDF from the inbuilt OSL shader library.
This can be used in OSL shaders only for now:
* phong(normal N, float exponent)
* phong_ramp(normal N, float exponent, color colors[8]
