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.
* Render Passes are now available for Subsurface Scattering (Direct, Indirect and Color pass).
This is part of my GSoC project, SVN merge of r58587, r58828 and r58835.
* After some feedback decided to remove this option from the Progressive integrator, it only makes sense for Non-Progressive where we have different values for the sample types.
* 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.
* Code cleanup to avoid duplicated enum code.
* Added a third type for conversion next to Point and Vector: Normal. This is basically the same result as with the Vector type, but normalizes the vector at the end.
Thanks to Brecht for code review!
* Fix some things which came up in code review. Includes some fixes for background lights and changes to variables, to avoid some castings.
Thanks to Brecht for code review! :)
* Avoid check for !LABEL_TRANSPARENT in "kernel_path_non_progressive_lighting", transparency is either handled in the outer loop or in the "kernel_path_indirect" function, but not here.
* Increase the maximum amount of closures per shader from 16 to 64, so more complex closure trees can be rendered.
I measured performance on CPU and GPU (Geforce 540M) and couldn't find a performance impact, but if someone encounters a noticeable impact on his system, please report.
* First step toward Subsurface Scattering render passes (Color, Direct and Indirect).
* Added UI, DNA and RNA for the new Passes on the Blender side.
* Basic Cycles integration.
* Only the SSS Color Pass works so far.
ToDo: Direct and Indirect Pass.
Should "subsurface" be a part of BsdfEval and "path_subsurface" of PathRadiance or is that the wrong way? Should it be integrated more like the AO render pass? Some input from Brecht or Stuart would be nice. :)
* "Auto Detect" now again uses the umber of cores, instead number of cores + 1.
This was added before we had Tile rendering and benchmarks on several systems showed that there is no gain with this now. There might be some slight difference (0.5% or so) slower/faster depending on the scene, but this is negligible.
* Add Presets for Sampling. This comes with a simple Preview and Final preset, but as this is varying a lot depending on the scene, they should just be a starting point. The user can add own presets here.
* Some UI layout changes to match the settings a bit better.
* Add a "Squared Samples" option to the UI, to use squared values for ease of use. This can make it easier from an artist point of view, to weak settings.
With this enabled, all Sample values will be squared. So 10 Samples become 100 Samples.
For the Non-Progressive integrator: 4 AA Samples * 5 Diffuse Samples would become 16 AA Samples * 25 Diffuse = 400 in total.
Patch by Matt Heimlich, with some minor edits by myself. Thanks!
* If Preview Samples are set to 0 (unlimited) it now assumes 65536 instead of INT_MAX.
This doesn't affect regular sampling, you can still enter fixed values of 100k or whatever.
* Fix the weird results with 800-804.3 Kelvin in SVM. This was an offset issue with the lookup table, made the table slightly larger now (from 954 to 956) which gives a small gap between the R/G/B components.
* Use Luminance also for values below 800 Kelvin, for consistency.
* Make it more clear for the user what affects 3D View and Final render.
* Static / Dynamic BVH only affects viewport, BVH Cache only final. (see BlenderSync::get_scene_params)
buffers option, it requires specific tile sizes and if they don't match what
OpenEXR expects file saving can get stuck.
Now I've made support for his optional, with a bl_use_save_buffers property for
RenderEngine, set to False by default.
* Added a Ray Depth output to the Light Path node, which returns the current ray bounce (0, 1, 2, 3...)
* This can be used to use different shaders for direct and indirect lighting and artificial effects.
Examples:
* http://www.pasteall.org/pic/show.php?id=55158 Here we use the output to apply a different shader to the third bounce. As in this example, you can use Math Nodes (Greater Than / Less Than) if you want to use values outside of the 0/1 range.
* http://www.pasteall.org/pic/show.php?id=55159 Here we restrict the maximum bounce on a per shader basis for the left sphere. This way it looks like we would only have 1 max bounce set in the scene "Light paths" panel.
This can be used to e.g. improve performance for objects far from the camera, which do not need full GI.
Technical notes:
* Implemented for both integrators and SVM/OSL.
* This is done by passing state.bounce to the shader_setup_from_* functions.
* Note: We don't pass state.bounce to kernel_shader_evaluate() and therefore shader_setup_from_displacement() method doesn't set the value, this is outside the path trace loop. Maybe a ToDo?
RGB color components gave non-grey results when you might no expect it.
What happens is that some of the color channels are zero in the direct light
pass because their channel is zero in the color pass. The direct light pass is
defined as lighting divided by the color pass, and we can't divide by zero. We
do a division after all samples are added together to ensure that multiplication
in the compositor gives the exact combined pass even with antialiasing, DoF, ..
Found a simple tweak here, instead of setting such channels to zero it will set
it to the average of other non-zero color channels, which makes the results look
like the expected grey.
Issue is caused by missing sse flags for Clang compilers,
this flags only was set for GNU C compilers.
Added if branch for Clang now, which contains the same
flags apart from -mfpmath=sse, This is because Clang was
claiming it's unused argument.
Probably OSX would need some further checks since it's
also using Clang. I've got no idea why it could have
worked for OSX before..
* After some more thinking, solved the remaining ToDos. :)
* Added is_object check to check if we have a valid object.
* If we operate on the world, and try to convert from/to object space, we now assume world space instead, same as OSL.
* Implementation of the node for SVM. This covers all possible transformations: World <> Object <> Camera space.
As far as I can tell, it also works fine with Motion Blur enabled.
ToDo:
* SVM differs from OSL, when the node is used on the world.
* 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.
texture coordinate that should automatically use the default normal or texture
coordinate appropriate for that node, rather than some fixed value specified by
the user.
* On nvidia Kepler GPUs (sm_30 and above), there are now 145 byte images available, instead of 95.
We could extend this to about 200 if needed.
Could not test this, as I don't have a Kepler GPU, so feedback on this would be appreciated.
Thanks to Brecht for review and some fixes. :)
* Add CUDA compiler version detection to cmake/scons/runtime
* Remove noinline in kernel_shader.h and reenable --use_fast_math if CUDA 5.x
is used, these were workarounds for CUDA 4.2 bugs
* Change max number of registers to 32 for sm 2.x (based on performance tests
from Martijn Berger and confirmed here), and also for NVidia OpenCL.
Overall it seems that with these changes and the latest CUDA 5.0 download, that
performance is as good as or better than the 2.67b release with the scenes and
graphics cards I tested.
On the BMW scene, this gives roughly a 10% speedup overall with clang/gcc, and 30%
speedup with visual studio (2008). It turns out visual studio was optimizing the
existing code quite poorly compared to pretty good autovectorization by clang/gcc,
but hand written SSE code also gives a smaller speed boost there.
This code isn't enabled when using the hair minimum width feature yet, need to
make that work with the SSE code still.
* Enable the Non-Progressive integrator on GPU (CUDA) for testing.
In order to compile the CUDA kernel with it, you need at least 6GB of system memory and CUDA Toolkit 5.0 or 5.5.
It should also work with CUDA Toolkit 4.2, but in this case you should have 12GB of RAM.
In case any problems arise, just change line 65 of kernel_types.h to disable Non-Progressive again.
-- #define __NON_PROGRESSIVE__
++ //#define __NON_PROGRESSIVE__
* Replaced the Brute Force version with a nice lookup table, this speeds it up a lot.
Patch by Philipp Oeser (lichtwerk) with some cleanup and changes by myself. Thanks!
ToDo:
* Temperature values between 800 and 804 Kelvin are wrong in SVM, check on this.
* 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.
and sm_30 cards, so hopefully it should all work now.
Also includes some warnings fixes related to nvcc compiler arguments, should make
no difference otherwise.
Apparently, it's bad idea to rely on compiler to cast NULL
which is (void*)0 to int -- and in fact if i was a compiler
would also generate an error.
Further, couldn't see why we need to pass NULL or 0 th add_node,
argument value is defautl to 0 already.
* 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.
don't have any way to deal with scripted node types yet, which could in principle by added with pynodes. The NodeCustomGroup type adds a way of scripting nodes by automating node groups which the
hardcoded system can then interpret like regular groups.
The new NodeCustomGroup type has the basic node_tree pointer property like the regular group node types and also uses the same socket interface system as regular groups. This means that input/output
sockets can be mapped to internal nodes in the same way as regular node groups in renderers and the compositor. On top of that, however, the NodeCustomGroup type can be subclassed in python scripts to flesh out
scripted node types with own draw functions, properties, updates and so on.
NB: Only cycles currently supports this node type and its derivatives, other systems may follow later.
* 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.
multiple importance sampling, so you can disable them for diffuse/glossy/transmission.
The Light Path node here is still weak and does not give this info. To make that
work we'd need to evaluate the shader multiple times which is slow and we can't
detect well enough when it is actually needed.
instead of sobol. So far one doesn't seem to be consistently better or worse than
the other for the same number of samples but more testing is needed.
The random number generator itself is slower than sobol for most number of samples,
except 16, 64, 256, .. because they can be computed faster. This can probably be
optimized, but we can do that when/if this actually turns out to be useful.
Paper this implementation is based on:
http://graphics.pixar.com/library/MultiJitteredSampling/
Also includes some refactoring of RNG code, fixing a Sobol correlation issue with
the first BSDF and < 16 samples, skipping some unneeded RNG calls and using a
simpler unit square to unit disk function.
* Revert r57203 (len() renaming)
There seems to be a problem with nVidia OpenCL after this and I haven't figured out the real cause yet.
Better to selectively enable native length() later, after figuring out what's wrong.
This fixes [#35612].
* Rename some math functions:
len -> length
len_squared -> length_squared
normalize_len -> normalize_length
* This way OpenCL uses its inbuilt length() function, rather than our own. The other two functions have been renamed for consistency.
* Tested CPU, CUDA and OpenCL compile, should be no functional changes.
* Cycles Mix closure could render strange effects, when the user entered a value out of the 0...1 range. This was already clamped for OSL, clamp for SVM as well.
the second time, as for example Intel CPU startup time is 9 seconds.
* Adds an cache for contexts and programs for each platform and device pair,
which also ensure now no two threads try to compile and write the binary cache
file at the same time.
* Change clFinish to clFlush so we don't block until the result is done, instead
it will block at the moment we copy back memory.
* Fix error in Cycles time_sleep implementation, does not affect any active code
though.
* Adds some (disabled) debugging code in the task scheduler.
Patch #35559 by Doug Gale.
Added an option to show backtrace from where
non-freed datablock was allocated from.
To enable this feature, simply enable DEBUG_BACKTRACE
in mallocn.c file and all unfreed datablocks will
be followed up by a backtrace.
Currently works on linux and osx only,
windows support is on TODO.
This feature is for sure disabled by default,
so does not affect any builds which don't
explicitly define DEBUG_BACKTRACE.
* Support using devices from all OpenCL platforms, so that you can use e.g. both
Intel and NVidia OpenCL implementations if you have them installed.
* Fix compile error due to missing fmodf after recent math node change.
* Enable advanced shading for Intel OpenCL.
* CYCLES_OPENCL_DEBUG environment variable for generating debug symbols so you
can debug with gdb. This crashes the compiler with Intel OpenCL on Linux though.
To make this work the preprocessed kernel source code is written out, as gdb
needs this.
* Show OpenCL compiler warnings even if the build succeeded.
* Some small fixes to initialize cdDevice to NULL, add missing NULL check when
creating buffer and add missing space at end of build options for Apple OpenCL.
* Fix crash with multi device + opencl, now e.g. CPU + GPU render should work.
I did a few tweaks to the code and also:
* Fix viewport render failing sometimes with Apple CPU OpenCL, was not taking
workgroup size limits into account properly.
* Add compile error when advanced shading in the Blender binary and OpenCL kernel
are not in sync.
* Some closures (Toon, Diffuse Ramp) were not assigned to a CLOSURE_IS_* define, which made them invisible on render passes.
* Westin closures had wrong type, Sheen is Diffuse, Backscatter is Glossy.
* 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.
- Removed grid-snapping for area coordinates on scaling windows.
That caused the areas to shrink or expand, and eventually corrupt screen layouts.
- Added simple but efficient life resize for OSX. I need to know why this is so much
code for Windows... I suggest Windows to just copy same method; dispatch the queue,
and just let the event system draw.
This was caused by a "hack" Daniel Genrich introduced in his moving obstacles commit in r46050. I suppose it was originally added to prevent issues with too fast moving obstacles, but now it ended up limiting maximum velocity of higher resolution simulations.
Here is an comparision of 184 resolution simulation (simulation area limited by adaptive domain):
https://www.miikah.org/blender/smoke_with_pressure_limit_hack.pnghttps://www.miikah.org/blender/smoke_without_pressure_limit_hack.png
I now reverted that hack until a better solution is found. Daniel, can you check this out? Pressure was limited to maximum of dt * dx (= dt / res) which doesn't make sense to limit pressure based on grid resolution. Maybe better to limit with a constant factor instead?
This caused high resolution smoke to always regenerate new tile when domain was reinitialized, slowing down especially adaptive domain simulations. Now noise tile is saved in Blender temp directory instead.
* 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).
* Also do pressure interpolation for brush size and spacing.
* Do smoothing of pressure when smooth stroke and sample average is enabled.
* Revert the OS X specific pressure change to pressure ^ 2.5, for low pressure
values like 0.05 it makes the pressure 100x lower, which is problematic. If
we need to adjust the pressure curve it should be done for all platforms.
Still weak:
* Pressure of first touch on tablet is difficult to control, usually it's low
which makes the stroke start out small or soft, but other times not. Finer
event capturing at ghost level would help, along with pressure changes without
mouse movement, but this may also need different paint stroke logic.
* Brush radius is rounded to integers, this gives noticeable stepping.
* Brush falloff is not antialiased, gives noticeable aliasing for small brush
sizes which was always a problem, but is more common with size pressure control.
So now, in the new "other" tex context, you can (depending on active data) have direct access to modifiers', force's or brushes' textures...
I also refactored a bit how texture contexts are handled (once again, we had some quite similar code in both space_buttons and RNA sources). This should also solve some harmless glitches like "no texture context selected in UI" sometimes when you remove data related to current texture (see e.g. after removing the material from default cube, in startup scene).
This usage of two different systems for textures, and the handling of switches between them, has been a bit tricky to get working right, but it is OK now I think. I also had to add a bool flag to buttons space, SB_TEX_USER_LIMITED (use_limited_texture_context in RNA), which indicates "new shading" texture code whether it has to ignore materials, lamps etc. (BI) or not (Cycles).
Btw, pinned textures from modifiers/force/etc. were also broken (showing nothing), now it should work too.
Thanks to Brecht for reviewing.
Another issue with the recent Ghost changes here. For some reason key up events
are not coming through when the command key is pressed. I can't figure out why,
for now just always handle them, still fixes the original bug.
interact better with system shortcuts.
This is a special shortcut for switching between views and does not get
delivered directly to our view when we pass it through the application key
event handling path. We only have a single OpenGL view, so there's no need to
pass it on to the application, instead just interpret it directly.
insert text in the text editor and do the associated operation like minimizing the
window or switching windows.
The code was always doing both without trying to ensure only one is done. Now we
integrate a bit better with the event handling and pass the event to NSApp, which
then decides to handle the event itself or pass it on to the window, from where
we then send it back to be handled.
Problem was that due to group proxy node the anisotropic node did not detect
early enough that it needs generated texture coordinate data to generate the
tangent. Now the proxy nodes are removed earlier.
for Apple OpenCL on OS X 10.8 and simple AO render.
Also environment variable CYCLES_OPENCL_TEST can now be set to CPU, GPU,
ACCELERATOR, DEFAULT or ALL values to test particuler devices.
give results that were either too weak or too strong, this makes it give more
predictable results. The downside is that it breaks backwards compatibility but
the previous behavior was almost broken.
* Code refactor of tile ordering to simplify the code and avoid some branching.
* Changed the Center method, so it really follows center -> corners, instead of the BI method, which was confusing sometimes.
the Bump node has a Normal input, so you can chain it after a Normal Map node.
Note that normal mapping always has to be done first because it is tied to the
particular mesh surface and tangents.
fullscreen option. It was possible to enable both at the same time which got
you stuck in a state where it was impossible to exit fullscreen. Now I've made
them mutually exlusive, only one can be enabled at the same time.
Note the reason we need to support both is because the new Lion fullscreen does
not work with multiple monitors, it will just give black screens on the other
monitors. This is a limitation of OS X, you can find many complaints about this
online.
after a bugfix for precision issues with low roughness. Now it renders them as
perfectly sharp which avoids the problematic calculations rather than increasing
the roughness.
Fixed by adding a "texture_user_property" member to spacebuts' context, and using it to get the prop identifier in ui script.
Thanks to Brecht for its advice!
The problem was (again) the x86 extended precision float register being used for
one float value while the other was rounded to lower precision. This caused the
strictly weak order requirement for std::sort to be broken.
a maximized Blender window in Ubuntu Unity. The window size would slightly change
as part of the unminimize effect.
Now cycles waits 0.2 seconds before restarting rendering after a viewport resize,
also a bit less flickery when changing the 3d view size in Blender itself.
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.
This is a experimental collision detection function, so the API might
change in the future.
Note: The simulation needs to be stepped before this function can be
used, otherwise the rigid body world might not be valid.
Patch [#34989] Bullet Convex sweep test API
by Vilem Novak (pildanovak), thanks!
After planar codecs support minimal FFmpeg was
bumped to 0.10 which was not so much nice because
it was only released only later last year.
Didn't find a way to make compatibility code local
in ffmpeg_compat, so there're some ifdefs in
audaspace and writeffmpeg.
Not entirely happy, but having a bit of ifdefs in
code better than lots of real PITA for platform
maintainers.
Now there is a single BVH traversal code with #ifdefs for various features.
At runtime it will then select the appropriate variation to use depending if
instancing, hair or motion blur is in use.
This makes scenes without hair render a bit faster, especially after the
minimum width feature was added. It's not the most beautiful code, but we can't
use c++ templates and there were already 4 copies, adding 4 more to handle the
hair case separately would be too much.
panel now has an option to specify how to use them. There's three options:
* Use: render layer samples override scene samples
* Bounded: bound render layer samples by scene samples
* Ignore: ignore render layer sample settings
Code is added to restrict the pixel size of strands in cycles. It works best with ribbon primitives and a preset for these is included. It uses distance dependent expansion of the strands and then stochastic strand removal to give a fading. To prevent a slowdown for triangle mesh objects in the BVH an extra visibility flag has been added. It is also only applied for camera rays.
The strand width settings are also changed, so that the particle size is not included in the width calculation. Instead there is a separate particle system parameter for width scaling.
AVCODEC_MAX_AUDIO_FRAME_SIZE was deprecated and
finally removed from current trunk.
Initial patch by Lawrence D'Oliveiro (ldo) with
own modification, Thanks!
The latest ffmpeg versions include a workaround to deal with a certain
pecularity in Canon DSLR footage: instead of decoding pictures with the
proper resolution of 1920x1080 they decode it with 1920x1088 and add a
black bar at the bottom.
Needless to say, that this screws up things in a lot of areas within blender
(proxy indices, mask animations etc.)
Since all blender versions besides Linux x86 32bit seem still to include
older ffmpeg versions which still contain this bug, this patch adds
a workaround for older versions until we have all versions on all platforms
up to date.
See also: http://git.libav.org/?p=libav.git;a=commit;h=30f515091c323da59c0f1b533703dedca2f4b95d
Custom implementation for resizing (GHOST_SizerWin32)
Some things still don't work:
* esc cancel
* max windows size
* aero (sizing) snap on win7
hbrBackground = 0 to disable clear screen.
Thanks to dfelinto for help in finding of root cause.
low roughness and same index of refraction.
Problem was bad float precision due to low roughness, which caused the pdf for
the different closures to not match properly.
* Cycles Render layers UI was broken after freestyle merge (changes were not merged). Did manual edits now with some tweaks.
* Some layout fixes for Mask Layer.
per render layer samples in addition to the progress bar.
Also fixed job progress bar not working at all on high DPI / retina, was so small
the actual progress was not visible.
Issue was caused by some mesa drivers does not support GL_RGBA16F.
Now added check around glTexImage2D to verify whether requested
internal format is actually supported. If not blender will fall
back to non-GLSL image display.
- GLSL shader wasn't aware of alpha predivide option,
always assuming alpha is straight. Gave wrong results
when displaying transparent float buffers.
- GLSL display wasn't aware of float buffers with number
of channels different from 4, crashing when trying to
display image with different number of channels.
This required a bit larger changes, namely now it's
possible to pass format (GL_RGB, GL_RGBAm GL_LUMINANCE)
to glaDrawPixelsTex, This also implied adding format to
glaDrawPixelsAuto and modifying all places where this
functions are called.
Now GLSL will handle both 3 and 4 channels buffers,
single channel images are handled by CPU.
- Replaced hack for render result displaying with a bit
different hack.
Namely CPU conversion will happen only during render,
once render is done GLSL would be used for displaying
render result on a screen.
This is so because of the way renderer updates parts
of the image -- it happens without respect to active
render layer in image user. This is harmless because
only display buffer is modifying, but this is tricky
because we don't have original buffer opened during
rendering.
One more related fix here was about when rendering
multiple layers, wrong image would be displaying when
rendering is done. Added a signal to invalidate
display buffer once rendering is done (only happens
when using multiple layers). This solves issue with
wrong buffer stuck on the display when using regular
CPU display space transform and if GLSL is available
it'll make image displayed with a GLSL shader.
- As an additional change, byte buffers now also uses
GLSL display transform.
So now only dutehr and RGB curves are stoppers for
using GLSL for all kind of display transforms.
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
Apparently C== allowed to have implementations of
OCIOImpl::setupGLSLDraw, OCIOImpl::finishGLSLDraw and
OCIOImpl::freeGLState in two different files.
STUPID!
* Unnecessary shader inputs inside the Mix Shader are now ignored, in case the factor is 0.0 / 1.0 and not connected.
This way we save some render time for complex node graphs.
Example: http://www.pasteall.org/pic/show.php?id=48226
Check the Mix Shader at the end: In this case, Cycles will now avoid the complete huge shader tree, and only calculate the Diffuse Shader.
Rendertime decreased from 1:50 min to 1:20 min on CPU. GPU rendering benefits as well from this.
This only affects SVM, OSL was already doing these optimizations.
