This is the minimal change required to start using modern CMake in the
blender build system. This change is designed to allow small
incremental changes to the build system rather than doing it in one
big bang which would be unmaintainable (for me)
The biggest functional change is, previously all libraries in the
`LIB` section of a `blender_add_lib` call had the `INTERFACE` scope,
which is rarely, if ever the correct scope. This diff changes this to
`PRIVATE`
Concrete implications of this diff :
The `LIB`, `INC` and `INC_SYS` sections of an `blender_add_lib` call
now allow scoping keywords (`PUBLIC`, `PRIVATE,` `INTERFACE`) to
declare the scope of the dependency.
Right now the only library using any modern cmake is
`bf_intern_atomic` which is an header only interface library that will
just advertise its include directories.
This allows us to clean up any `CMakeLists.txt` that adds
`../../../intern/atomic` to its `INC` section to remove it in `INC` by
adding a `PRIVATE bf_intern_atomic` to the `LIB` section.
Pull Request: https://projects.blender.org/blender/blender/pulls/107858
- "Front"/"Back": 'put something at the front/back' or 'the front/back
face of something'. (e. g. the Empty Image options, Depth and Side
option, both use the same strings as enum, which should be avoided
in some languages).
- "Flip": invert, as in normals, or mirror, as in an image.
- "Path": a path to a resource, in general a file but sometimes a
datablock, as opposed to a trajectory in space.
- "Join": disambiguate for the Grease Pencil operator, which may use a
different word as that for meshes.
- "Wave": an ondulating motion, as opposed to a fluid dynamics motion.
- "Step": can mean the distance between two things, or a number of
times to do something. In this case it is better to use the plural.
- "Edge": generally the edges of a mesh, but can also mean edge
detection. Additionally, it was used for the option to enable
Freestyle. This was changed to "Use Freestyle".
- "Boundary": the limit of a grease pencil drawing for filling
purposes, as opposed to the external limit of a (non-manifold) mesh.
- "Rotations": can be translated to something like "Turns", in the
context of a spiral.
Pull Request: https://projects.blender.org/blender/blender/pulls/108213
For repeat / extend / mirror mode, both wrap and read_clip functions did
the bounds check. Removing it improves performance between 0.5% and 1.5%
in the classroom scene in one test. Clip mode is unchanged.
Pull Request: https://projects.blender.org/blender/blender/pulls/109304
The Voronoi Smooth F1 mode breaks when the Smoothness is 0 for OSL. This is
due to a zero division in the shader.
To fix this, standard F1 is used when Smoothness is 0.
Pull Request: https://projects.blender.org/blender/blender/pulls/109255
During recent testing, the oldest 101.4032 (windows) and <25812 (linux)
drivers led to crashes during JIT compilation, so we bump the
requirement to newer 101.4313 and 25812.14 drivers that do incorporate
the required fixes.
Pull Request: https://projects.blender.org/blender/blender/pulls/109281
for energy preservation and better compatibility with other renderes. Ref: #108505
Point light now behaves the same as a spherical mesh light with the same overall energy (scaling from emission strength to power is \(4\pi^2R^2\)).
# Cycles
## Comparison
| Mesh Light | This patch | Previous behavior |
| -------- | -------- | -------- |
|  |  |  |
The behavior stays the same when `radius = 0`.
| This patch | Previous behavior |
| -------- | -------- |
|  |  |
No obvious performance change observed.
## Sampling
When shading point lies outside the sphere, sample the spanned solid angle uniformly.
When shading point lies inside the sphere, sample spherical direction uniformly when inside volume or the surface is transmissive, otherwise sample cosine-weighted upper hemisphere.
## Light Tree
When shading point lies outside the sphere, treat as a disk light spanning the same solid angle.
When shading point lies inside the sphere, it behaves like a background light, with estimated outgoing radiance
\[L_o=\int f_aL_i\cos\theta_i\mathrm{d}\omega_i=\int f_a\frac{E}{\pi r^2}\cos\theta_i\mathrm{d}\omega_i\approx f_a \frac{E}{r^2}\],
with \(f_a\) being the BSDF and \(E\) `measure.energy` in `light_tree.cpp`.
The importance calculation for `LIGHT_POINT` is
\[L_o=f_a E\cos\theta_i\frac{\cos\theta}{d^2}\].
Consider `min_importance = 0` because maximal incidence angle is \(\pi\), we could substitute \(d^2\) with \(\frac{r^2}{2}\) so the averaged outgoing radiance is \(f_a \frac{E}{r^2}\).
This only holds for non-transmissive surface, but should be fine to use in volume.
# EEVEE
When shading point lies outside the sphere, the sphere light is equivalent to a disk light spanning the same solid angle. The sine of the new half-angle is the tangent of the previous half-angle.
When shading point lies inside the sphere, integrating over the cosine-weighted hemisphere gives 1.0.
## Comparison with Cycles
The plane is diffuse, the blue sphere has specular component.
| Before | |After ||
|---|--|--|--|
|Cycles|EEVEE|Cycles|EEVEE|
|||||
Pull Request: https://projects.blender.org/blender/blender/pulls/108506
When baking only indirect lighting, light sampling is skipped at the
first bounce. However, light evaluation is still done, so depending
on how the MIS weights end up more or less of the direct lighting
still ends up in the bake.
This is most noticeable with background lighting, but can also be
reproduced with e.g. point lights with a large radius.
Pull Request: https://projects.blender.org/blender/blender/pulls/108955
Better to disable than crashing, as we are not expecting a quick fix. The cause
is likely similar to issues with the light tree, which was already disabled.
Ref #104013
Somehow the implementation for the main function to load point clouds
data was missing although everything else to support point clouds was
there. Compilers were more than happy to convert the IPointsSchema to
another schema type for the compilation to succeed, and the crash
occurs because the points schema does not contain the same data as the
compiler's chosen schema (in this case an ICurvesSchema).
Another crash was found due to the radius array not being properly
initialized and left with a size of 0, when Cycles expects a full array.
Happens with systems which do not provide GOLD linker: the linking state
would failing with some missing symbols and print about missing libsycl.so.6.
Seems that BFD linker expects to resolve all symbols, even the indirectly
used ones. This is somewhat counter-intuitive and is not how LLD, GOLD,
or MOLD worls.
The current state of the CMakeLists.txt does request the cycles_bvh to be
linked against SYCL_LIBRARIES. However, the SYCL was only requested to be found
if WITH_CYCLES_DEVICE_ONEAP is true.
Arguably the SYCL_LIBRARIES should only be linked-in into cycles_bvh if
EMBREE_STATIC_LIB, but that does not solve the issue with BFD.
This change makes it so the SYCL is requested to be found if the oneAPI
device is enabled, or if the Embree is detected to require/use SYCL
support.
Pull Request: https://projects.blender.org/blender/blender/pulls/108965
When baking e.g. the Diffuse pass, use the existing filter logic to
disable glossy and transmission closures.
This reduces baking time and noise when baking individual components
of complex materials.
The problem here was that when direct light contibutions to baking were
disabled, the kernel just skipped all direct lighting evaluation.
However, at secondary bounces, "direct light" would actually end up
being indirect (since there's an extra bounce along the way), but
we're still skipping it.
Therefore, only apply direct lighting skipping at the first bounce.
Store subdivision surface creases in two new named float attributes:
- `crease_vert`
- `crease_edge`
This is similar to 2a56403cb0dbcbc1dfb19a9bf7e6434517cbdca9.
The attributes are naming conventions, so their data type and domain
aren't enforced, and may be interpolated when necessary. Editing tools
and the subdivision surface modifier use the hard-coded name. It might
be best if these were edited as generic attributes in the future, but
in the meantime using generic attributes helps.
The attributes are visible in the list, which is how they're now meant
to be removed. They are now interchangeable with any tool that works
with the generic attribute system-- even tools like vertex paint can
affect creases now.
This is a breaking change. Forward compatibility isn't preserved for
versions before 3.6, and the `crease` property in RNA is removed in
favor of making a smaller API surface area with just the attribute API.
`Mesh.vertex_creases` and `Mesh.edge_creases` now just return the
matching attribute if possible, and are now implemented in Python.
New functions `*ensure` and `*remove` also replace the operators to
add and remove the layers for Python.
A few extrude node test files have to be updated because of different
(now generic) attribute interpolation behavior.
Pull Request: https://projects.blender.org/blender/blender/pulls/108089
This fixes an issue where the light tree sampling algorithm would
discard light samples from groups of distance lights with an angle
greater than 0 when it shouldn't.
Pull Request: https://projects.blender.org/blender/blender/pulls/108832
Fractal noise is the idea of evaluating the same noise function multiple times with
different input parameters on each layer and then mixing the results. The individual
layers are usually called octaves.
The number of layers is controlled with a "Detail" slider.
The "Lacunarity" input controls a factor by which each successive layer gets scaled.
The existing Noise node already supports fractal noise. Now the Voronoi Noise node
supports it as well. The node also has a new "Normalize" property that ensures that
the output values stay in a [0.0, 1.0] range. That is except for the F2 feature where
in rare cases the output may be outside that range even with "Normalize" turned on.
How the individual octaves are mixed depends on the feature and output socket:
- F1/Smooth F1/F2:
- Distance/Color output:
The individual Distance/Color octaves are first multiplied by a factor of
`Roughness ^ (#layers - 1.0)` then added together to create the final output.
- Position output:
Each Position octave gets linearly interpolated with the combined output of the
previous octaves. The Roughness input serves as an interpolation factor with
0.0 resutling in only using the combined output of the previous octaves and
1.0 resulting in only using the current highest octave.
- Distance to Edge:
- Distance output:
The Distance octaves are mixed exactly like the Position octaves for F1/Smooth F1/F2.
It should be noted that Voronoi Noise is a relatively slow noise function, especially
at higher dimensions. Increasing the "Detail" makes it even slower. Therefore, when
optimizing a scene one should consider trying to use simpler noise functions instead
of Voronoi if the final result is close enough.
Pull Request: https://projects.blender.org/blender/blender/pulls/106827
