This commit adds a new distribution to the Glossy, Anisotropic and Glass BSDFs that implements the
multiple-scattering microfacet model described in the paper "Multiple-Scattering Microfacet BSDFs with the Smith Model".
Essentially, the improvement is that unlike classical GGX, which only models single scattering and assumes
the contribution of multiple bounces to be zero, this new model performs a random walk on the microsurface until
the ray leaves it again, which ensures perfect energy conservation.
In practise, this means that the "darkening problem" - GGX materials becoming darker with increasing
roughness - is solved in a physically correct and efficient way.
The downside of this model is that it has no (known) analytic expression for evalation. However, it can be
evaluated stochastically, and although the correct PDF isn't known either, the properties of MIS and the
balance heuristic guarantee an unbiased result at the cost of slightly higher noise.
Reviewers: dingto, #cycles, brecht
Reviewed By: dingto, #cycles, brecht
Subscribers: bliblubli, ace_dragon, gregzaal, brecht, harvester, dingto, marcog, swerner, jtheninja, Blendify, nutel
Differential Revision: https://developer.blender.org/D2002
The improved Hosek / Wilkie model was added during my GSoC 2013 and the default since then.
The older model was kinda kept for compatibility, but after more than 2 years it's time to remove it.
The Hosek / Wilkie model is more realistic anyway, and people who really want a day / night transition can mix the Sky Shader with another one (e.g. color) and fade between the two.
This commit changes the way how we pass bounce information to the Light
Path node. Instead of manualy copying the bounces into ShaderData, we now
directly pass PathState. This reduces the arguments that we need to pass
around and also makes it easier to extend the feature.
This commit also exposes the Transmission Bounce Depth to the Light Path
node. It works similar to the Transparent Depth Output: Replace a
Transmission lightpath after X bounces with another shader, e.g a Diffuse
one. This can be used to avoid black surfaces, due to low amount of max
bounces.
Reviewed by Sergey and Brecht, thanks for some hlp with this.
I tested compilation and usage on CPU (SVM and OSL), CUDA, OpenCL Split
and Mega kernel. Hopefully this covers all devices. :)
While SCons building system was serving us really good for ages it's no longer
having much attention by the developers and started to become quite a difficult
task to maintain.
What's even worse -- there started to be quite serious divergence between SCons
and CMake which was only accumulating over the releases now. The fact that none
of the active developers are really using SCons and that our main studio is also
using CMake spotting bugs in the SCons builds became quite a difficult task and
we aren't always spotting them in time.
Meanwhile CMake became really mature building system which is available on every
platform we support and arguably it's also easier and more robust to use.
This commit includes:
- Removal of actual SCons building system
- Removal of SCons git submodule
- Removal of documentation which is stored in the sources and covers SCons
- Tweaks to the buildbot master to stop using SCons submodule
(this change requires deploying to the server)
- Tweaks to the install dependencies script to skip installing or mentioning
SCons building system
- Tweaks to various helper scripts to avoid mention of SCons folders/files
as well
Reviewers: mont29, dingto, dfelinto, lukastoenne, lukasstockner97, brecht, Severin, merwin, aligorith, psy-fi, campbellbarton, juicyfruit
Reviewed By: campbellbarton, juicyfruit
Differential Revision: https://developer.blender.org/D1680
This commit adds "Bands Saw" and "Rings Saw" to the options for the Wave texture node in Cycles, behaving similar to the Saw option in BI textures.
Requested by @cekuhnen on BA.
Reviewers: dingto, sergey
Subscribers: cekuhnen
Differential Revision: https://developer.blender.org/D1699
Vector mapping node was doing some weird mapping of both original and mapped
coordinates. Mapping of original coordinates was caused by the clamping nature
of the LUT generated from the node. Mapping of the mapped value again was quite
totally obscure -- one needed to constantly keep in mind that actual value will
be scaled up and moved down.
This commit makes it so values in the vector curve mapping are always absolute.
In fact, it is now behaving quite the same as RGB curve mapping node and the
code could be de-duplicated. Keeping the code duplicated for a bit so it's more
clear what exact parts of the node changed.
Reviewers: brecht
Subscribers: bassamk
Differential Revision: https://developer.blender.org/D1672
Previously RGB Curves node will clamp input to 0..1 which is rather useless
when one wants to use HDR image textures and do bit of correction on them.
Now kernel code supports extrapolation of baked LUT based on first/last two
table points and performs linear extrapolation.
The only tricky part is to guess the range to bake the LUT for. Currently
it's using simple approach -- minmax of the input curves. While this behaves
ok for the simple cases it's easy to trick the system up causing incorrect
results.
Not sure we can solve those issues in a general case and since the new code
is giving more expected results it's not that bad actually. In the worst
case artist migh always create explicit point to make sure LUT is created
for the needed HDR range.
Reviewers: brecht, juicyfruit
Subscribers: sebastian_k
Differential Revision: https://developer.blender.org/D1658
This must have happened months ago, but as I did not `make clean` any build folder since then,
so only noted that today.
Issue is same as dirty patch we have to apply to ODL sources before building it in install_deps.sh - for
some mysterious reason, it has become impossible to compoile .osl files into .oso ones without
giving explicit output file name (otherwise it just produces `.oso` file - utterly stupid and useless).
We could probably fix that in own OSL source, but think being explicit here does not hurt anyway, so...
Let's go the easy way.
This commit exposes the interpolation parameter for environment textures (requested by DolpheenDream on IRC), just as it already is for image textures.
Reviewers: sergey
Differential Revision: https://developer.blender.org/D1544
Added some extra seed to the hash, so it's now less likely to give repetitive
patters at values around zero.
This will change distribution of bricks for existing files. but it's something
inevitable.
Currently only two mappings are supported by API, which is Repeat (old behavior)
and new Clip behavior. Internally this extension is being converted to periodic
flag which was already supported but wasn't exposed.
There's no support for OpenCL yet because of the way how we pack images into a
single texture.
Those settings are not exposed to UI or anywhere else and there should be no
functional changes so far.
The idea of this node is to sampling of 3D voxels at a given coordinate
supporting different mapping strategies (world space mapping, object
local space etc).
Currently not in use, it's a preparation step for supporting point density
textures.
Older OSX has major issues with sincos() function, it's likely a big in OSL
or LLVM. For until we've updated to new versions of this libraries we'll use
a workaround to prevent possible crashes on all the platforms.
Shouldn't be that bad because it's mainly used for anisotropic shader where
angle is usually constant.
This fix is safe for inclusion into final Blender 2.75 release.
Same as last commit, code is unused and this one actually would have required some fixes,
as these variants output values outside the 0-1 value range, which doesn't fit Cycles shader design.
Let's finally delete this code, after 4 years of being unused,
there really is no excuse anymore.
If we decide to extend the procedural textures in SVM, we can do this anytime in the future.
This attribute missed derivatives calculation.
Not totally sure what's the proper approach for algebraic derivative
calculation, so calculating them by definition. This isn't fastest
way to do it in this case and could be replaced with some smarter magic
in the wireframe calculation loop.
At least currently implemented approach is better than nothing.
This attribute means how "pointy" the geometry surface is, which allows to do
effects like dirt maps and wear-off effects on render geometry. This means the
attribute is calculated for the final mesh which means no baking (which implies
UV unwrap) is needed. Apart from this the behavior is quite close to how vertex
dirty colors works.
The new attribute is available as an output socket of Geometry node.
There's no penalty for the render time, only some delay on scene preparation
(the delay is linear of the mesh complexity).
Reviewers: brecht, juicyfruit
Subscribers: eyecandy, venomgfx
Differential Revision: https://developer.blender.org/D1086
This is the same as blender internal's texture mapping from another object,
so this way it's possible to control texture space of one object by another.
Quite straightforward change apart from the workaround for the stupidness of
the dependency graph. Now shader has flag telling that it depends on object
transform. This is the simplest way to know which shaders needs to be tagged
for update when object changes. This might give some false-positive tags now
but reducing them should not be priority for Cycles and rather be a priority
to bring new dependency graph.
Also GLSL preview does not support using other object for mapping.
This is actually correct for BI shading as well and to be addressed as
a part of general GLSL viewport improvements since it's not really clear
how to support this in GLSL.
Reviewers: brecht, juicyfruit
Subscribers: eyecandy, venomgfx
Differential Revision: https://developer.blender.org/D1021
This way Cycles finally becomes feature-full on image projections
compared to Blender Internal and Gooseberry Project Team could
finally finish the movie.
This reverts commit 1549fea9995c348bc14a9105df5e460644e2b33a.
After some further discussion with other developers in the team it becomes
clear there's no correct solution here. It is just more matter of what's
more convenient in particular case.
We're just going back to old code to avoid possible frustration with the
older files in newer blenders. This also means all HSV/HSL is considered
to be "linear" in the shading nodes.
Would be ported to 2.73 final.
These nodes were assuming sRGB input/output which is for sure wrong for the
shader pipeline which works in the linear space.
So now conversion to/from linear space happens in these nodes which makes them
making sence in the shader context but which might change look and feel of
existing scenes.
This mainly happens when over-saturating already saturated color.
After some discussion with Campbell and loads of tests we decided
to clamp the result RGB color. As an alternative we might want to
clamp corrected HSV values instead, but that would lead to some
larger changes in the render results.
TODO: The same is to be done for compositor nodes.
This is basically just a wrapper class, which maps the generic call from the OSL spec to our closures.
Example usage:
shader microfacet_osl(
color Color = color(0.8),
int Distribution = 0,
normal Normal = N,
vector Tangent = normalize(dPdu),
float RoughnessU = 0.0,
float RoughnessV = 0.0,
float IOR = 1.4,
int Refract = 0,
output closure color BSDF = 0)
{
if (Distribution == 0)
BSDF = Color * microfacet("ggx", Normal, Tangent, RoughnessU, RoughnessV, IOR, Refract);
else
BSDF = Color * microfacet("beckmann", Normal, Tangent, RoughnessU, RoughnessV, IOR, Refract);
}
After discussion with cambo here we decided it's better to choose arbitrary side of the box
(in this case it's X-axis) and use image from it. That's better than doing a blackness.
P.S. This is literally a corner case anyway.
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.
This adds a fresnel conductive OSL preset to the Text Editor. Based on a patch by Lukas Stockner.
Differential revision: https://developer.blender.org/D145
See the differential for details.
