This probably should always have been the value used, really.
Now, instead of reporting `Qualcomm Technologies Inc`, it reports the more informative `Snapdragon(R) X Elite - X1E78100 - Qualcomm(R) Oryon(TM) CPU` on a Thinkpad T14s Gen6 device.
Pull Request: https://projects.blender.org/blender/blender/pulls/128808
- Deduplicate Fisheye projection code
- Replace spherical/cartesian conversions with shared helpers
- Replace transforms from/to local coordinate systems with shared helpers
The main type of repeated transform that's not covered here is `to/from_coords`, but with separate values for xy and z (e.g. BSDFs that already computed `dot(wi, N)` earlier, so they only need `dot(wi, X)` and `dot(wi, Y)` later). Could also be replaced, but it would feel weirdly specific for a helper function.
Pull Request: https://projects.blender.org/blender/blender/pulls/125999
Previously, Cycles only supported the Henyey-Greenstein phase function for volume scattering.
While HG is flexible and works for a wide range of effects, sometimes a more physically accurate
phase function may be needed for realism.
Therefore, this adds three new phase functions to the code:
Rayleigh: For particles with a size below the wavelength of light, mostly athmospheric scattering.
Fournier-Forand: For realistic underwater scattering.
Draine: Fairly specific on its own (mostly for interstellar dust), but useful for the next entry.
Mie: Approximates Mie scattering in water droplets using a mix of Draine and HG phase functions.
These phase functions can be combined using Mix nodes as usual.
Co-authored-by: Lukas Stockner <lukas@lukasstockner.de>
Pull Request: https://projects.blender.org/blender/blender/pulls/123532
`atan2(0, 0)` is undefined on many platforms. To ensure consistent
result across platforms, we return `0` in this case.
Note only the behavior of the shader node `Artan2` is changed here.
During shading, we might still produce `atan2(0, 0)` internally and
cause different results across platforms, but that usually happens with
single samples and is not obvious, plus checking this condition all the
time is costly. If later we find out it's indeed necessary to change all
the invocation of `atan2(0, 0)`, we could change the wrapper functions
in `metal/compat.h` and `mtl_shader_defines.msl`.
Pull Request: https://projects.blender.org/blender/blender/pulls/126951
Align Cycles SVM and EEVEE's rendering of the vector math node
in reflect mode with OSL when the normal vector is 0,0,0.
This is done by using safe_normalize rather than normalize on the
normal vector. Which also fixes a NaN in the reflect mode in this
specific configuration.
Pull Request: https://projects.blender.org/blender/blender/pulls/125688
The function direction_to_fisheye_lens_polynomial computes the inverse of
fisheye_lens_polynomial_to_direction.
Previously the function worked almost correctly if all parameters except k_0
and k_1 were zero (in that case it was correct except for flipping the x-axis).
I replaced the fixed-point iteration (?) by Newton's method and implemented a
test to make sure it works correctly with a wider range of parameter sets.
Pull Request: https://projects.blender.org/blender/blender/pulls/123737
Precompiled Cycles kernels make up a considerable fraction of the total size of
Blender builds nowadays. As we add more features and support for more
architectures, this will only continue to increase.
However, since these kernels tend to be quite compressible, we can save a lot
of storage by storing them in compressed form and decompressing the required
kernel(s) during loading.
By using Zstandard compression with a high level, we can get decent compression
ratios (~5x for the current kernels) while keeping decompression time low
(about 30ms in the worse case in my tests). And since we already require zstd
for Blender, this doesn't introduce a new dependency.
While the main improvement is to the size of the extracted Blender installation
(which is reduced by ~400-500MB currently), this also shrinks the download on
Windows, since .zip's deflate compression is less effective. It doesn't help on
Linux since we're already using .tar.xz there, but the smaller installed size
is still a good thing.
See #123522 for initial discussion.
Pull Request: https://projects.blender.org/blender/blender/pulls/123557
This patch implements a new Gabor noise node based on [1] but with the
improvements from [2] and the phasor formulation from [3].
We compare with the most popular existing implementation, that of OSL,
from the user's point of view:
- This implementation produces C1 continuous noise as opposed to the
non continuous OSL implementation, so it can be used for bump
mapping and is generally smother. This is achieved by windowing the
Gabor kernel using a Hann window.
- The Bandwidth input of OSL was hard-coded to 1 and was replaced with
a frequency input, which OSL hard codes to 2, since frequency is
more natural to control. This is even more true now that that Gabor
kernel is windowed as opposed to truncated, which means increasing
the bandwidth will just turn the Gaussian component of the Gabor
into a Hann window. While decreasing the bandwidth will eliminate
the harmonic from the Gabor kernel, which is the point of Gabor
noise.
- OSL had three discrete modes of operation for orienting the kernel.
Anisotropic, Isotropic, and a hybrid mode. While this implementation
provides a continuous Anisotropy parameter which users are already
familiar with from the Glossy BSDF node.
- This implementation provides not just the Gabor noise value, but
also its phase and intensity components. The Gabor noise value is
basically sin(phase) * intensity, but the phase is arguably more
useful since it does not suffer from the low contrast issues that
Gabor suffers from. While the intensity is useful to hide the
singularities in the phase.
- This implementation converges faster that OSL's relative to the
impulse count, so we fix the impulses count to 8 for simplicitly.
- This implementation does not implement anisotropic filtering.
Future improvements to the node includes implementing surface noise and
filtering. As well as extending the spectral control of the noise,
either by providing specialized kernels as was done in #110802, or by
providing some more procedural control over the frequencies of the
Gabor.
References:
[1]: Lagae, Ares, et al. "Procedural noise using sparse Gabor
convolution." ACM Transactions on Graphics (TOG) 28.3 (2009): 1-10.
[2]: Tavernier, Vincent, et al. "Making gabor noise fast and
normalized." Eurographics 2019-40th Annual Conference of the European
Association for Computer Graphics. 2019.
[3]: Tricard, Thibault, et al. "Procedural phasor noise." ACM
Transactions on Graphics (TOG) 38.4 (2019): 1-13.
Pull Request: https://projects.blender.org/blender/blender/pulls/121820
This fixes#69535 and #98930.
We use a equi-solid-angle sampling algorithm for rectangular area lights,
but it is not particularly robust for small area lights (either small
in general and/or small because it's being viewed from grazing angles).
The actual sampling part is fine since it just gets clamped into the
valid area anyways, and the difference isn't notable for small lights.
However, we also need to compute the solid angle to get the sampling PDF,
and that computation is quite sensitive to numerical issues for small
values.
Therefore, this commit adds a fallback path for small values, which instead
uses the classic equi-area sampling PDF term times the area-to-solid-angle
Jacobian term. This approximation assumes that all points on the light have
the same distance and angle to the sampling point, which is of course not
strictly the case, but it's close enough for small area lights and better
than failing altogether.
Pull Request: https://projects.blender.org/blender/blender/pulls/122323
This is an implementation of thin film iridescence in the Principled BSDF based on "A Practical Extension to Microfacet Theory for the Modeling of Varying Iridescence".
There are still several open topics that are left for future work:
- Currently, the thin film only affects dielectric Fresnel, not metallic. Properly specifying thin films on metals requires a proper conductive Fresnel term with complex IOR inputs, any attempt of trying to hack it into the F82 model we currently use for the Principled BSDF is fundamentally flawed. In the future, we'll add a node for proper conductive Fresnel, including thin films.
- The F0/F90 control is not very elegantly implemented right now. It fundamentally works, but enabling thin film while using a Specular Tint causes a jump in appearance since the models integrate it differently. Then again, thin film interference is a physical effect, so of course a non-physical tweak doesn't play nicely with it.
- The white point handling is currently quite crude. In short: The code computes XYZ values of the reflectance spectrum, but we'd need the XYZ values of the product of the reflectance spectrum and the neutral illuminant of the working color space. Currently, this is addressed by just dividing by the XYZ values of the illuminant, but it would be better to do a proper chromatic adaptation transform or to use the proper reference curves for the working space instead of the XYZ curves from the paper.
Pull Request: https://projects.blender.org/blender/blender/pulls/118477
The Perlin noise algorithms suffer from precision issues when a coordinate
is greater than about 250000.
To fix this the Perlin noise texture is repeated every 100000 on each axis.
This causes discontinuities every 100000, however at such scales this
usually shouldn't be noticeable.
Pull Request: https://projects.blender.org/blender/blender/pulls/119884
By restricting the sample range along the ray to the valid segment.
Supports
**Mesh Light**
- [x] restrict the ray segment to the side with MIS
**Area Light**
- [x] when the spread is zero, find the intersection of the ray and the bounding box/cylinder of the rectangle/ellipse area light beam
- [x] when the spread is non-zero, find the intersection of the ray and the minimal enclosing cone of the area light beam
*note the result is also unbiased when we just consider the cone from the sampled point in volume segment. Far away from the light source it's less noisy than the current solution, but near the light source it's much noisier. We have to restrict the sample region on the area light to the part that lits the ray then, I haven't tried yet to see if it would be less noisy.*
**Point Light**
- [x] the complete ray segment should be valid.
**Spot Light**
- [x] intersect the ray with the spot light cone
- [x] support non-zero radius
Pull Request: https://projects.blender.org/blender/blender/pulls/119438
This commit updates all defines, compiler flags and cleans up some code for unused CPU capabilities.
There should be no functional change, unless it's run on a CPU that supports sse41 but not sse42. It will fallback to the SSE2 kernel in this case.
In preparation for the new SSE4.2 minimum in Blender 4.2.
Pull Request: https://projects.blender.org/blender/blender/pulls/118043
Seems to be a fairly niche type, but some people (apparently mostly in the automotive space) use it.
Also improves the handling of IES files in general and lets Cycles accept IES files that are technically violating the spec - which seems to be most of them...
Pull Request: https://projects.blender.org/blender/blender/pulls/114689
The IES parser in Cycles would lead to heap buffer overflow error
when non-supported or invalid data is provided to it.
The error was caused by the way how stirng is copied to vector
skipping the last null-terminator. Later C-style string utilities
are used for parsing, and they expect the data to be null-terminated.
It is unclear why data needs to be stored as vector: storing it as
string simplifies initialization.
Easiest to reproduce the issue is to use Blender build with address
sanitizer enabled.
Pull Request: https://projects.blender.org/blender/blender/pulls/116752
Along with the 4.1 libraries upgrade, we are bumping the clang-format
version from 8-12 to 17. This affects quite a few files.
If not already the case, you may consider pointing your IDE to the
clang-format binary bundled with the Blender precompiled libraries.
Fix issues related to NaN normals in some situations by trying
to detect when these cases might occur and just reverting back
to default normals.
As a side effect of these changes, OSL now behaves correctly
when given a non-normalized normal.
Pull Request: https://projects.blender.org/blender/blender/pulls/114960
The NanoVDB headers are not compatible with Metal due to missing address
space qualifiers. We currently have a big patch for NanoVDB header
files, which is difficult to update for OpenVDB 11. Instead extract a
few hundred lines of code from NanoVDB to do just what we need.
Pull Request: https://projects.blender.org/blender/blender/pulls/115992
by doing the subtraction first and then take the dot product. This
offers higher precision than taking the dot product first and then
subtract the result, especially in the cases where the ray origin is
very far away from the sphere center.
Use the common BVH utilities header for this.
Added a special type qualifier ccl_ray_data which is defined to ccl_private
for all platforms but Metal. On Metal it is defined to ray_data.
The tricky part is that the BVH utilities are wrapped into the Metal context
class. In some of the BVH functions the context has been already constructed,
but it wasn't done in all the callbacks.
From a quick render tests of the Junkshop benchmark scene there is no render
time difference,
No functional changes are expected.
Pull Request: https://projects.blender.org/blender/blender/pulls/111967
The Metal backend combines all kernel sources into a single string
and passes it to the compiler. Doing so natively has a disadvantage
of making it hard to find sources of mistakes in code when working
on the kernel source as the source file name and line number info
is lost. For example, the error would look like:
```
program_source:187004:3: error: use of undeclared identifier 'metalrt_intersection_point_shadow_force_error'
metalrt_intersection_point_shadow_force_error(launch_params_metal,
^
```
This patch makes it so the #line pragmas are inserted into the
combined source source code, so that the compiler errors are easier
to find immediately. For example the error from above becomes
```
source/kernel/device/metal/kernel.metal:809:3: error: use of undeclared identifier 'metalrt_intersection_point_shadow_force_error'
metalrt_intersection_point_shadow_force_error(launch_params_metal,
^
```
The code is a slightly modified functionality from the source
processing used for OpenCL in Blender 2.80.
Pull Request: https://projects.blender.org/blender/blender/pulls/111959
based on concentric disk mapping.
Concentric disk mapping was already present, but not used everywhere.
Now `sample_cos_hemisphere()`, `sample_uniform_hemisphere()`, and
`sample_uniform_cone()` use concentric disk mapping.
This changes the noise in many test images.
Pull Request: https://projects.blender.org/blender/blender/pulls/109774
