This is also an important mathematical operation that can be folded
if it is known that one argument is a certain constant. For colors
the operation is provided as a Gamma node.
The SVM Gamma node needs a small fix to make it follow the 0 ^ 0 == 1
rule, same as the Power node, or the Gamma node itself in OSL mode.
Reviewers: #cycles
Differential Revision: https://developer.blender.org/D2263
Bump mapping was happening in world space while displacement happens in object
space, causing shading errors when displacement type was used with bump mapping.
To fix this the proper transforms are added to bump nodes. This is only done
for automatic bump mapping however, to avoid visual changes from other uses of
bump mapping. It would be nice to do this for all bump mapping to be consistent
but that will have to wait till we can break compatibility.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2191
The if branches were reordered when the original patch was
committed, which broke the implicit non-NULL guarantee on link.
To prevent re-occurrence, add a couple of unit tests.
As a result of other folding simplifications it may happen that
two type conversion nodes end up directly connected. In some
cases it may be possible to then remove both. A realistic case
might be an optimized out Mix RGB node used to blend vectors.
It seems it's safe to optimize when B is a float3 type
(color, vector), and A is float3 or float.
Reviewers: #cycles, sergey
Reviewed By: #cycles, sergey
Subscribers: sergey
Differential Revision: https://developer.blender.org/D2134
These values often either turn the node into a no-op, or even make it
evaluate to 0 no matter what the other input value is, thus allowing
deletion of a branch of the node graph that otherwise is not constant.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2085
These are complex nodes, and it's conceivable they may end up constant
in some circumstances within node groups, so folding support is useful.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2084
- Nodification of shader nodes changed default strength from 10 to 1.
If that was intentional, IMO should happen as a separate commit.
- Fixed indentation.
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
In the OSL node compilation code for the Environment Texture, is_linear was used as a socket.
However, there was no socket for it, which caused Blender to crash.
Adding a socket doesn't really make sense since it's an internal value and not a parameter
of the node, so it now just uses the variable directly.
Until now, single channel textures were packed into a float4, wasting 3 floats per pixel. Memory usage of such textures is now reduced by 3/4.
Voxel Attributes such as density, flame and heat benefit from this, but also Bumpmaps with one channel.
This commit also includes some cleanup and code deduplication for image loading.
Example Smoke render from Cosmos Laundromat: http://www.pasteall.org/pic/show.php?id=102972
Memory here went down from ~600MB to ~300MB.
Reviewers: #cycles, brecht
Differential Revision: https://developer.blender.org/D1981
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.
