Float2 are now a new type for attributes in Cycles. Before, the choices
for attribute storage were float and float3, the latter padded to
float4. This meant that UV maps were inflated to twice the size
necessary.
Reviewers: brecht, sergey
Reviewed By: brecht
Subscribers: #cycles
Tags: #cycles
Differential Revision: https://developer.blender.org/D4409
There is a generic function to retrieve float and float3 attributes
`primitive_attribute_float` and primitive_attribute_float3`. Inside
these functions an prioritised if-else construction checked where
the attribute is stored and then retrieved from that location.
Actually the calling function most of the time already knows where
the data is stored. So we could simplify this by splitting these
functions and remove the check logic.
This patch splits the `primitive_attribute_float?` functions into
`primitive_surface_attribute_float?` and `primitive_volume_attribute_float?`.
What leads to less branching and more optimum kernels.
The original function is still being used by OSL and `svm_node_attr`.
This will reduce the compilation time and render time for kernels.
Especially in production scenes there is a lot of benefit.
Impact in compilation times
job | scene_name | previous | new | percentage
-------+-----------------+----------+-------+------------
t61513 | empty | 10.63 | 10.66 | 0%
t61513 | bmw | 17.91 | 17.65 | 1%
t61513 | fishycat | 19.57 | 17.68 | 10%
t61513 | barbershop | 54.10 | 24.41 | 55%
t61513 | classroom | 17.55 | 16.29 | 7%
t61513 | koro | 18.92 | 18.05 | 5%
t61513 | pavillion | 17.43 | 16.52 | 5%
t61513 | splash279 | 16.48 | 14.91 | 10%
t61513 | volume_emission | 36.22 | 21.60 | 40%
Impact in render times
job | scene_name | previous | new | percentage
-------+-----------------+----------+--------+------------
61513 | empty | 21.06 | 20.35 | 3%
61513 | bmw | 198.44 | 190.05 | 4%
61513 | fishycat | 394.20 | 401.25 | -2%
61513 | barbershop | 1188.16 | 912.39 | 23%
61513 | classroom | 341.08 | 340.38 | 0%
61513 | koro | 472.43 | 471.80 | 0%
61513 | pavillion | 905.77 | 899.80 | 1%
61513 | splash279 | 55.26 | 54.86 | 1%
61513 | volume_emission | 62.59 | 61.70 | 1%
There is also a possitive impact when using CPU and CUDA, but they are small.
I didn't split the hair logic from the surface logic due to:
* Hair and surface use same attribute types. It was not clear if it could be
splitted when looking at the code only.
* Hair and surface are quick to compile and to read. So the benefit is quite
small.
Differential Revision: https://developer.blender.org/D4375
Values outside the 0..1 range produce negative colors, so now clamp to that
range everywhere. Also fixes improper handling of hue > 2.0 in some places.
Failed as in did not allocate due to possibly weight cutoff.
Tryign to allocated Extra storage for closure in such situation
will consfuse Cycles and cause crashes later one due to obscure
values in ShaderData.
While changing the shading normal is a great way to add additional detail to a model, there are some problems with it.
One of them is that at grazing angles and/or strong changes to the normal, the reflected ray can end up pointing into the actual geometry, which results in a black spot.
This patch helps avoid this by automatically reducing the strength of the bump/normal map if the reflected direction would end up too shallow or inside the geometry.
Differential Revision: https://developer.blender.org/D2574
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
This works for Cycles, Eevee, texture nodes and compositing. It helps to
reduce the number of math nodes required in various node setups.
Differential Revision: https://developer.blender.org/D3537
This means the shader can now be used for procedural texturing. New
settings on the node are Samples, Inside, Local Only and Distance.
Original patch by Lukas with further changes by Brecht.
Differential Revision: https://developer.blender.org/D3479
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
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 Math node currently has the normal atan() function, but for
actual angles this is fairly useless without additional nodes to handle the signs.
Since the node has two inputs anyways, it only makes sense to add an arctan2 option.
Reviewers: sergey, brecht
Differential Revision: https://developer.blender.org/D3430
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.
Similar to the Principled BSDF, this should make it easier to set up volume
materials. Smoke and fire can be rendererd with just a single principled
volume node, the appropriate attributes will be used when available. The node
also works for simpler homogeneous volumes like water or mist.
Differential Revision: https://developer.blender.org/D3033
We now continue transparent paths after diffuse/glossy/transmission/volume
bounces are exceeded. This avoids unexpected boundaries in volumes with
transparent boundaries. It is also required for MIS to work correctly with
transparent surfaces, as we also continue through these in shadow rays.
The main visible changes is that volumes will now be lit by the background
even at volume bounces 0, same as surfaces.
Fixes T53914 and T54103.
It seems to be useful still in cases where the particle are distributed in
a particular order or pattern, to colorize them along with that. This isn't
really well defined, but might as well avoid breaking backwards compatibility
for now.
This is like the only way to add variety to hair which is created
using simple children. Used here for the hair.
Maybe not ideal, but the time will show.
Burley SSS uses a bit of strange thing where the albedo and closure weight are
different, which makes the subsurface color act a bit like a subsurface radius
indirectly by the way the Burley SSS profile works.
This can't work for random walk SSS though, and it's not clear to me that this
is actually a good idea since it's really the subsurface radius that is supposed
to control this. For now I'll leave Burley SSS working the same to not break
backwards compatibility.
It is basically brute force volume scattering within the mesh, but part
of the SSS code for faster performance. The main difference with actual
volume scattering is that we assume the boundaries are diffuse and that
all lighting is coming through this boundary from outside the volume.
This gives much more accurate results for thin features and low density.
Some challenges remain however:
* Significantly more noisy than BSSRDF. Adding Dwivedi sampling may help
here, but it's unclear still how much it helps in real world cases.
* Due to this being a volumetric method, geometry like eyes or mouth can
darken the skin on the outside. We may be able to reduce this effect,
or users can compensate for it by reducing the scattering radius in
such areas.
* Sharp corners are quite bright. This matches actual volume rendering
and results in some other renderers, but maybe not so much real world
objects.
Differential Revision: https://developer.blender.org/D3054
This adds midlevel and object/world space for displacement, and a
vector displacement node with tangent/object/world space, midlevel
and scale.
Note that tangent space vector displacement still is not exactly
compatible with maps created by other software, this will require
changes to the tangent computation.
Differential Revision: https://developer.blender.org/D1734
Previously we stored each color channel in a single closure, which was
convenient for sampling a closure and channel together. But this doesn't
work so well for algorithms where we want to render multiple color
channels together.
Previously only scalar displacement along the normal was supported,
now displacement can go in any direction. For backwards compatibility,
a Displacement node will be automatically inserted in existing files.
This will make it possible to support vector displacement maps in the
future. It's already possible to use them to some extent, but requires
a manual shader node setup. For tangent space maps the right tangent
may also not be available yet, depends on the map.
Differential Revision: https://developer.blender.org/D3015
This converts object space height to world space displacement, to be
linked to the new vector displacement material output.
Differential Revision: https://developer.blender.org/D3015
