Basically we can not use sharp closure as a substitude when filter glossy is
used. This is because we can not blur sharp reflection/refraction.
This is quite quick and not really clean implementation. Not really happy
with manual handling of original settings, but this is as good as we can do
in the quick patch. It's a good acknowledgment and we now can re-consider
some aspects of graph simplification to make such cases more natively
supported.
P.S. This failure would have been shown by our regression tests, so please,
bother a bit to run Cycles's test sweep before doing such optimizations.
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
operator< had wrong brackets, changed it now to be more clear.
Fix#33404: crash GPU rendering with OSL option still enabled. There was a check
to disable OSL in this case, but it shouldn't have modified scene->params because
this is used for comparison in scene->modified().
Also some simple OSL optimization, passing thread data pointer directly instead
of via thread local storage, and creating ustrings for attribute lookup.
Documentation here:
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/OSLhttp://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.65/Cycles
These changes require an OSL build from this repository:
https://github.com/DingTo/OpenShadingLanguage
The lib/ OSL has not been updated yet, so you might want to keep OSL disabled
until that is done.
Still todo:
* Auto update for external .osl files not working currently, press update manually
* Node could indicate better when a refresh is needed
* Attributes like UV or generated coordinates may be missing when requested from
an OSL shader, need a way to request them to be loaded by cycles
* Expose string, enum and other non-socket parameters
* Scons build support
Thanks to Thomas, Lukas and Dalai for the implementation.
The sampled color ramp data is passed to OSL as a color array. This has to be done as actual float[3] array though, since the Cycles float3 type actually contains 4 floats, leading to shifting color components in the array.
Additional parameter set functions for arrays have been added to the Cycles OSL interface for this purpose.
