This is a physically-based, easy-to-use shader for rendering hair and fur,
with controls for melanin, roughness and randomization.
Based on the paper "A Practical and Controllable Hair and Fur Model for
Production Path Tracing".
Implemented by Leonardo E. Segovia and Lukas Stockner, part of Google
Summer of Code 2018.
Features to get the 2nd, 3rd, 4th closest point instead of the closest, and
various distance metrics. No viewport/Eevee support yet.
Patch by Michel Anders, Charlie Jolly and Brecht Van Lommel.
Differential Revision: https://developer.blender.org/D3503
Textures in 16 bit integer format are sometimes used for displacement, bump and normal maps and can be exported by tools like Substance Painter. Without this patch, Cycles would promote those textures to single precision floating point, causing them to take up twice as much memory as needed.
Reviewers: #cycles, brecht, sergey
Reviewed By: #cycles, brecht, sergey
Subscribers: sergey, dingto, #cycles
Tags: #cycles
Differential Revision: https://developer.blender.org/D3523
The latest clang compiler (at least the one in Xcode 9.4.1) warns about the register keyword and macro expansions using defined().
Since these warnings come from third party code, we can't address them directly in Blender. Silencing them via #pramgas will
at least keep the warnings during a build down to the ones that are relevant to Blender code.
I've limited it to just the RGB<->XYZ stuff for now, correct image handling is the next step.
Reviewers: brecht, sergey
Differential Revision: https://developer.blender.org/D3478
There is one legit place in the code where memcpy was used as an
optimization trick. Was needed for older version of GCC, but now
it should be re-evaluated and checked if it still helps to have
that trick.
In other places it's somewhat lazy programming to zero out all
object members. That is absolutely unsafe, at the moment when
less trivial class is used as a member in that object things
will break.
Other cases were using memcpy into an object which comes from
an external library. We don't control that object, and we can
not guarantee it will always be safe for such memory tricks
and debugging bugs caused by such low level access is far fun.
Ideally we need to use more proper C++, but needs to be done with
big care, including benchmarks of each change, For now do
annoying but simple cast to void*.
This patch adds support for IES files, a file format that is commonly used to store the directional intensity distribution of light sources.
The new IES node is supposed to be plugged into the Strength input of the Emission node of the lamp.
Since people generating IES files do not really seem to care about the standard, the parser is flexible enough to accept all test files I have tried.
Some common weirdnesses are distributing values over multiple lines that should go into one line, using commas instead of spaces as delimiters and adding various useless stuff at the end of the file.
The user interface of the node is similar to the script node, the user can either select an internal Text or load a file.
Internally, IES files are handled similar to Image textures: They are stored in slots by the LightManager and each unique IES is assigned to one slot.
The local coordinate system of the lamp is used, so that the direction of the light can be changed. For UI reasons, it's usually best to add an area light,
rotate it and then change its type, since especially the point light does not immediately show its local coordinate system in the viewport.
Reviewers: #cycles, dingto, sergey, brecht
Reviewed By: #cycles, dingto, brecht
Subscribers: OgDEV, crazyrobinhood, secundar, cardboard, pisuke, intrah, swerner, micah_denn, harvester, gottfried, disnel, campbellbarton, duarteframos, Lapineige, brecht, juicyfruit, dingto, marek, rickyblender, bliblubli, lockal, sergey
Differential Revision: https://developer.blender.org/D1543
The GPU kernel needs to use atomics for accumulation since all offsets are processed in
parallel, but on CPUs that's not the case, so we can disable them there for a considerable speedup.
The implementation is pretty straightforward.
In Cycles, sampling the shapes is currently done w.r.t. area instead of solid angle.
There is a paper on solid angle sampling for disks [1], but the described algorithm is based on
simply sampling the enclosing square and rejecting samples outside of the disk, which is not exactly
great for Cycles' RNG (we'd need to setup a LCG for the repeated sampling) and for GPU divergence.
Even worse, the algorithm is only defined for disks. For ellipses, the basic idea still works, but a
way to analytically calculate the solid angle is required. This is technically possible [2], but the
calculation is extremely complex and still requires a lookup table for the Heuman Lambda function.
Therefore, I've decided to not implement that for now, we could still look into it later on.
In Eevee, the code uses the existing ltc_evaluate_disk to implement the lighting calculations.
[1]: "Solid Angle Sampling of Disk and Cylinder Lights"
[2]: "Analytical solution for the solid angle subtended at any point by an ellipse via a point source radiation vector potential"
Reviewers: sergey, brecht, fclem
Differential Revision: https://developer.blender.org/D3171
Use C++11 threads when available, and native critical section on Windows.
Later on we can remove pthread code when C+11 becomes required.
Differential Revision: https://developer.blender.org/D3116
With better directory layout and more proper include
statements we can avoid several local modifications,
such as changing config.h for Windows Glog and the
ones related on pass-through statements in logging
headers in Glog.
This commit also makes unused functions not-a-warning
for external code.
This save a little memory and copying in the kernel by storing only a 4x3
matrix instead of a 4x4 matrix. We already did this in a few places, and
those don't need to be special exceptions anymore now.
This is in preparation of making Transform affine only, and also gives us
a little extra type safety so we don't accidentally treat it as a regular
4x4 matrix.
The purpose of the previous code refactoring is to make the code more readable,
but combined with this change benchmarks also render about 2-3% faster with an
NVIDIA Titan Xp.
around the volume.
We generate a tight mesh around the active voxels of the volume in order
to effectively skip empty space, and start volume ray marching as close
to interesting volume data as possible. See code comments for details on
how the mesh generation algorithm works.
This gives up to 2x speedups in some scenes.
Reviewed by: brecht, dingto
Reviewers: #cycles
Subscribers: lvxejay, jtheninja, brecht
Differential Revision: https://developer.blender.org/D3038
