Commit Graph

55 Commits

Author SHA1 Message Date
Clément Foucault
c302b7de7b Refactor: EEVEE: Simplify Gbuffer packing
Implementation of #145417

For more information see pull request.

Pull Request: https://projects.blender.org/blender/blender/pulls/145520
2025-09-10 12:17:21 +02:00
Jacques Lucke
32c301e3cf Shader Nodes: support repeat zones, closures and bundles
This adds a function that can turn an existing `bNodeTree` into an inlined one.
The new node tree has all node groups, repeat zones, closures and bundles
inlined. So it's just a flat tree that ideally can be consumed easily by render
engines. As part of the process, it also does constant folding.

The goal is to support more advanced features from geometry nodes (repeat zones,
etc.) in shader nodes which the evaluator is more limited because it has to be
able to run on the GPU. Creating an inlined `bNodeTree` is likely the most
direct way to get but may also be limiting in the future. Since this is a fairly
local change, it's likely still worth it to support these features in all render
engines without having to make their evaluators significantly more complex.

Some limitations apply here that do not apply in Geometry Nodes. For example,
the iterations count in a repeat zone has to be a constant after constant
folding.

There is also a `Test Inlining Shader Nodes` operator that creates the inlined
tree and creates a group node for it. This is just for testing purposes.

#145811 will make this functionality available to the Python API as well so that
external renderers can use it too.
2025-09-09 16:15:43 +02:00
Jesse Yurkovich
3e3ee35e9d Fix #145711: Packed images may fail to export with USD
Certain packed images, like those loaded directly into memory with
`BKE_image_packfiles_from_mem`, would cause USD to process the images as
"in memory" rather than as "packed" because the API was not removing the
IMG_GEN_TILE flag.

Additionally, be sure to use the packed filepath whenever possible
rather than the name given to the Image datablock as this ensures the
correct file names are used inside the USD file and for the resulting
file on disk after export.

This also fixes 2 render tests which now match when compared to the
native renders.

Pull Request: https://projects.blender.org/blender/blender/pulls/145749
2025-09-05 19:41:20 +02:00
Brecht Van Lommel
6a083a5464 Color Management: Add working color space for blend files
* Store scene linear to XYZ conversion matrix in each blend file, along
  with the colorspace name. The matrix is the source of truth. The name
  is currently only used for error logging about unknown color spaces.
* Add Working Space option in color management panel, to change the
  working space for the entire blend file. Changing this will pop up
  a dialog, with a default enabled option to convert all colors in
  the blend file to the new working space. Note this is necessarily only
  an approximation.
* Link and append automatically converts to the color space of the main
  open blend file.
* There is builtin support for Rec.709, Rec.2020 and ACEScg working spaces,
  in addition to the working space of custom OpenColorIO configs.
* Undo of working space for linked datablocks isn't quite correct when going
  to a smaller gamut working space. This can be fixed by reloading the file
  so the linked datablocks are reloaded.

Compatibility with blend files saved with a custom OpenColorIO config
is tricky, as we can not detect this.

* We assume that if the blend file has no information about the scene
  linear color space, it is the default one from the active OCIO config.
  And the same for any blend files linked or appended. This is effectively
  the same behavior as before.
* Now that there is a warning when color spaces are missing, it is more
  likely that a user will notice something is wrong and only save the
  blend file with the correct config active.
* As no automatic working space conversion happens on file load, there is
  an opportunity to correct things by changing the working space with
  "Convert Colors" disabled. This can also be scripted for all blend files
  in a project.

Ref #144911

Pull Request: https://projects.blender.org/blender/blender/pulls/145476
2025-09-05 19:04:47 +02:00
Amogh Shivaram
11d98c14b7 Fix #144258: Cycles: Subsurface scattering doesn't work with shadow linking
When shadow linking is enabled, `intersect_dedicated_light` is scheduled even
if the `PATH_RAY_SUBSURFACE` flag is set. This checks the flag and schedules
`intersect_subsurface` instead.

Pull Request: https://projects.blender.org/blender/blender/pulls/145621
2025-09-05 15:31:50 +02:00
Brecht Van Lommel
62eac6da17 Tests: Update bake tests for new selection requirements
Ref #137389

Pull Request: https://projects.blender.org/blender/blender/pulls/145502
2025-09-01 12:40:49 +02:00
Miguel Pozo
ddb4aa2595 Fix: Draw: Update overlapping octrees reference image
Changed in #138449.
Missing in 8036f5e19d.

Pull Request: https://projects.blender.org/blender/blender/pulls/145255
2025-08-27 20:12:31 +02:00
Clément Foucault
8036f5e19d Tests: Update EEVEE and Workbench OpenVDB test after recent change
Changed in #138449.
2025-08-27 10:53:37 +02:00
Alaska
a31d022e69 Tests: Add Cycles test for scene with many unique materials
In recent history there have been two issues leading to corrupt
rendering or crashes on the GPU in scenes with 300 or more unique
materials. #144713 and #141171.

To help detect these issues earlier on, this commit adds a new Cycles
render test that uses 400 unique materials.

Pull Request: https://projects.blender.org/blender/blender/pulls/145187
2025-08-27 10:36:47 +02:00
Clément Foucault
ba4589e894 DRW: New Curve Drawing
Implementation of the design task #142969.

This adds the following:
- Exact GPU interpolation of curves of all types.
- Radius attribute support.
- Cyclic curve support.
- Resolution attribute support.
- New Cylinder hair shape type.
![image.png](/attachments/a8e7aea0-b0e5-4694-b660-89fb3df1ddcd)

What changed:
- EEVEE doesn't compute random normals for strand hairs anymore. These are considered legacy now.
- EEVEE now have an internal shadow bias to avoid self shadowing on hair.
- Workbench Curves Strip display option is no longer flat and has better shading.
- Legacy Hair particle system evaluates radius at control points before applying additional subdivision. This now matches Cycles.
- Color Attribute Node without a name do not fetch the active color attribute anymore. This now matches Cycles.

Notes:
- This is not 100% matching the CPU implementation for interpolation (see the epsilons in the tests).
- Legacy Hair Particle points is now stored in local space after interpolation.

The new cylinder shape allows for more correct hair shading in workbench and better intersection in EEVEE.

|      | Strand | Strip | Cylinder |
| ---- | --- | --- | --- |
| Main | ![main_strand.png](/attachments/67d3b792-962c-4272-a92c-1c0c7c6cf8de) | ![main_strip.png](/attachments/f2aa3575-368e-4fbb-b888-74df845918f1) | N/A |
| PR   | ![pr_strand.png](/attachments/cc012483-25f0-491f-a06e-ad3029981d47) | ![pr_strip.png](/attachments/73fa2f5c-5252-4b30-a334-e935ed0fb938) | ![pr_cylinder.png](/attachments/3133b2d4-a6f2-41ee-8e2d-f6fd00db0c8d) |

|      | Strand | Strip | Cylinder |
| ---- | --- | --- | --- |
| Main | ![main_strand_closeup.png](/attachments/730bd79c-6762-446d-819b-3ea47961ff9f) |![main_strip_closeup.png](/attachments/d9ace578-cfeb-4895-9896-3625b6ad7a02) | N/A |
| PR   | ![pr_strand_closeup.png](/attachments/ac8f3b0c-6ef6-4d54-b714-6322f9865036)|![pr_strip_closeup.png](/attachments/8504711a-955b-4ab2-aa3d-c2d114baf9d4)| ![pr_cylinder_closeup.png](/attachments/1e2899a8-0a5c-431f-ac6c-5184d87e9598) |

Cyclic Curve, Mixed curve type, and proper radius support:
![image.png](/attachments/7f0bf05e-62ee-4ae9-aef9-a5599249b8d7)

Test file for attribute lookup: [test_attribute_lookup.blend](/attachments/1d54dd06-379b-4480-a1c5-96adc1953f77)

Follow Up Tasks:
- Correct full tube segments orientation based on tangent and normal attributes
- Correct V resolution property per object
- More attribute type support (currently only color)

TODO:
- [x] Attribute Loading Changes
  - [x] Generic Attributes
  - [x] Length Attribute
  - [x] Intercept Attribute
  - [x] Original Coordinate Attribute
- [x] Cyclic Curves
- [x] Legacy Hair Particle conversion
  - [x] Attribute Loading
  - [x] Additional Subdivision
- [x] Move some function to generic headers (VertBuf, OffsetIndices)
- [x] Fix default UV/Color attribute assignment

Pull Request: https://projects.blender.org/blender/blender/pulls/143180
2025-08-27 09:49:43 +02:00
Lukas Tönne
12f0bc7736 Fix #138388: Use grid voxel corners as value locations like OpenVDB
Blender grid rendering interprets voxel transforms in such a way that the voxel
values are located at the center of a voxel. This is inconsistent with OpenVDB
where the values are located at the lower corners for the purpose or sampling
and related algorithms.

While it is possible to offset grids when communicating with the OpenVDB
library, this is also error-prone and does not add any major advantage.
Every time a grid is passed to OpenVDB we currently have to take care to
transform by half a voxel to ensure correct sampling weights are used that match
the density displayed by the viewport rendering.

This patch changes volume grid generation, conversion, and rendering code so
that grid transforms match the corner-located values in OpenVDB.

- The volume primitive cube node aligns the grid transform with the location of
  the first value, which is now also the same as min/max bounds input of the
  node.
- Mesh<->Grid conversion does no longer require offsetting grid transform and
  mesh vertices respectively by 0.5 voxels.
- Texture space for viewport rendering is offset by half a voxel, so that it
  covers the same area as before and voxel centers remain at the same texture
  space locations.

Co-authored-by: Brecht Van Lommel <brecht@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/138449
2025-08-26 12:27:20 +02:00
Sergey Sharybin
a020907844 Multires Bake: Implement vector displacement baking
Supports baking to object and tangent space.

Compatible with Cycles Vector Displacement node which has the
(tangent, normal, bitangent) convention.

The viewport situation is a bit confusing: seems that Eevee
does not handle vector displacement properly and rips all faces
apart. Cycles renders the displaced object correctly.

Not entirely happy with the UI, as displacement space does not
really belong to the Output, but so doesn't Low Resolution Mesh.
Perhaps the best would be to have a separate pass to revisit the
settings, and also make it more clear what the Low Resolution Mesh
actually does.

Pull Request: https://projects.blender.org/blender/blender/pulls/145014
2025-08-25 14:23:35 +02:00
Sergey Sharybin
628f53a28c Refactor: Consolidate baking settings into BakeData
Almost all settings were duplicated between BakeData and RenderData.
The only missing field was the bake type, which is stored as a custom
property in Cycles.

This change:
- Removes unused bake_samples and bake_biasdist.
- Migrates settings like bake_margin to BakeData.
- Switches multires baker to use bake_margin.
- Introduces bake type in the BakeData, the same way how it was
  defined in RenderData::bake_mode.

Pull Request: https://projects.blender.org/blender/blender/pulls/144984
2025-08-22 19:18:03 +02:00
Sergey Sharybin
8348438cae Multires bake: Rework baking high-res displacement
This change makes it so baking displacement to the high-resolution mesh
(Use Low Resolution Mesh option is OFF, displacement is calculated
between top multi-resolution level and subdivided viewport level mesh)
uses texture UVs and tangent space from the high-res mesh.

This matches intended use-case when object baked with such configuration
have subdivision surface applied to them bringing overall resolution to
the same level as the highest multi-resolution level.

The issue was simple to see when baking high-res displacement for an
object which uses "Keep Corners, Junctions" UV smoothing.

The unfortunate aspect is increased memory usage due to calculation of
the grid index and grid UV mapping, but it is not too bad (12 bytes per
loop, so is like 48Mb per million face). Feels like there is a way to
optimize it by utilizing knowledge that high-res mesh faces are created
in a specific order, but also feels it is not that important at this
moment.

Pull Request: https://projects.blender.org/blender/blender/pulls/144935
2025-08-22 18:24:57 +02:00
Sergey Sharybin
e0154de320 Rework Bake from Multires
The main idea is to switch Bake from Multires from legacy DerivedMesh
to Subdiv. On the development side of things this change removes a lot
of code, also making it easier easier to rework CustomData and related
topics, without being pulled down by the DerivedMesh.

On the user level switch to Subdiv means:

- Much more closer handling of the multi-resolution data: the derived
  mesh code was close, but not exactly the same when it comes to the
  final look of mesh.

  Other than less obvious cases (like old DerivedMesh approach doing
  recursive subdivision instead of pushing subdivided vertices on the
  limit surface) there are more obvious ones like difference in edge
  creases, and non-supported vertex creases by the DerivedMesh.

- UV interpolation is done correctly now when baking to non-base level
  (baking to multi-resolution level >= 1).

  Previously in this case the old derived mesh interpolation was used
  to interpolate face-varying data, which gives different results from
  the OpenSubdiv interpolation.

- Ngon faces are properly supported now.

A possible remaining issue is the fact that getting normal from CCG
always uses smooth interpolation. Based on the code it always has been
the case, so while it is something to look into it might be considered
a separate topic to dig into.
2025-08-22 17:59:27 +02:00
Weizhen Huang
3dc73a3fda Tests: update GPU volume tests
New files are added since 5646d9a5ca

Pull Request: https://projects.blender.org/blender/blender/pulls/144622
2025-08-15 18:15:34 +02:00
Weizhen Huang
df496eb894 Cycles: use one-tap stochastic interpolation for volume
It has ~1.2x speed-up on CPU and ~1.5x speed-up on GPU (tested on Metal
M2 Ultra).

Individual samples are noisier, but equal time renders are mostly
better.

Note that volume emission renders differently than before.

Pull Request: https://projects.blender.org/blender/blender/pulls/144451
2025-08-14 15:22:44 +02:00
Weizhen Huang
5646d9a5ca Cycles: Add and update volume test files 2025-08-13 10:28:50 +02:00
Brecht Van Lommel
402080f938 Tests: Remove broken image path in tests
This causes EEVEE tests to fail now that these are logged as errors and
`--debug-exit-on-error` is used when running tests.

Pull Request: https://projects.blender.org/blender/blender/pulls/144376
2025-08-11 21:18:38 +02:00
Dawid Kurek
9afa991316 Hydra: Handle dome light rotation
This refactors the code for world to dome light to be shared between USD and
Hydra, and makes rotations work for Hydra the same way they do in USD.

One small behavior change is that missing image files now render black,
matching Cycles and EEVEE more closely.

Co-authored-by: Brecht Van Lommel <brecht@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/143035
2025-08-04 15:58:37 +02:00
Amogh Shivaram
ff4d840cf8 Cycles: Add polarized Fresnel function for conductors
This PR adds a new `fresnel_conductor_polarized` function, which calculates reflectance and phase shift (if requested) for both parallel and perpendicular polarized light. This is needed for applying thin film iridescence to conductors (see !141131).

For consistency, this PR also makes `fresnel_conductor` call `fresnel_conductor_polarized` instead of using a fast approximation of the Fresnel equations that is inaccurate at lower n and k values. This will change the output of some Metallic BSDF renders using Physical Conductor and prevent discrepancies when enabling thin film iridescence.

I didn't do any rigorous performance testing, but from timing the functions outside of Blender, `fresnel_conductor_polarized` is significantly slower than the approximation, between 1.5-3x depending on the compiler. This makes sense because it has three square roots and the approximation has none. In some informal tests with metallic_multiggx_physical.blend modified to have more spheres, the new renders took around 1-2% longer on both CPU and GPU.

There are some avoidable inefficiencies in this approach of just calling `fresnel_conductor_polarized`:

- one of the three square roots could be saved since `fresnel_conductor` never needs the phase shift and there are simplifications possible when only calculating the reflectance
- there are several unnecessary multiplications by 1.0 since `fresnel_conductor` uses relative IOR and `fresnel_conductor_polarized` doesn't, though those could get optimized out if inlined

Pull Request: https://projects.blender.org/blender/blender/pulls/143903
2025-08-04 15:36:36 +02:00
Brecht Van Lommel
24a7c42766 Cleanup: Remove unused and outdated render test files
Pull Request: https://projects.blender.org/blender/blender/pulls/143438
2025-08-01 16:02:48 +02:00
Patrick Mours
6487395fa5 Cycles: Add linear curve shape
Add new "Linear 3D Curves" option in the Curves panel in the render
properties. This renders curves as linear segments rather than smooth
curves, for faster render time at the cost of accuracy.

On NVIDIA Blackwell GPUs, this can give a 6x speedup compared to smooth
curves, due to hardware acceleration. On NVIDIA Ada there is still
a 3x speedup, and CPU and other GPU backends will also render this
faster.

A difference with smooth curves is that these have end caps, as this
was simpler to implement and they are usually helpful anyway.

In the future this functionality will also be used to properly support
the CURVE_TYPE_POLY on the new curves object.

Pull Request: https://projects.blender.org/blender/blender/pulls/139735
2025-07-29 17:05:01 +02:00
Sergey Sharybin
dcae48d1d3 Cycles: Add Portal Depth light pass information
It allows to implement tricks based on a knowledge whether the path
ever cam through a portal or not, and even something more advanced
based on the number of portals.

The main current objective is for strokes shading: stroke shader
uses Ray Portal BSDF to place ray to the center of the stroke and
point it in the direction of the surface it is generated for. This
gives stroke a single color which matches shading of the original
object. For this usecase to work the ray bounced from the original
surface should ignore the strokes, which is now possible by using
Portal Depth input and mixing with the Transparent BSDF. It also
helps to make shading look better when there are multiple stroke
layers.

A solution of using portal depth is chosen over a single flag due
to various factors:
- Last time we've looked into it it was a bit tricky to implement
	as a flag due to us running out of bits.
- It feels to be more flexible solution, even though it is a bit
	hard to come up with 100% compelling setup for it.
- It needs to be slightly different from the current "Is Foo"
	flags, and be more "Is Portal Descendant" or something.

An extra uint16 is added to the state to count the portal depth,
but it is only allocated for scenes that use Ray Portal BSDF.

Portal BSDF still increments Transparent bounce, as it is required
to have some "limiting" factor so that ray does not get infinitely
move to different place of the scene.

Ref #125213

Pull Request: https://projects.blender.org/blender/blender/pulls/143107
2025-07-25 18:09:38 +02:00
Brecht Van Lommel
678ccd4a61 Cycles: Change default material to match Blender and EEVEE
Use Principled BSDF instead of Diffuse BSDF. This is a breaking change but
likely does not affect many scenes significantly. It adds some specularity
when an object does not have a a material assigned.

Fix #142538

Pull Request: https://projects.blender.org/blender/blender/pulls/142703
2025-07-22 15:54:30 +02:00
Alaska
736559f320 Fix #139718: Always treat OSL cameras as inside a volume
Cycles automatically tries to decide if the camera ray should be a
surface or a volume + surface camera ray by checking to see if the
scene contains a volumetric material, and if it does, is it near
where the camera rays are expected to spawn. This step is done
during scene intialization.

With the OSL camera, it is impratical to predict where the
camera rays will spawn during scene intialization, which makes it
impratical to predict if the OSL camera ray will spawn near a
volumetric object. So this commit marks all OSL cameras as
"inside a volume", leading to the spawning of volume + surface camera
rays for OSL cameras while the scene contains a volumetric material.

This leads to increased render times ranging between 1% - 5% in scenes
that use a OSL camera, has a volumetric object in it, and the
volumetric object is far away from the camera. Every other scene should
see no performance impact.

Testing was done on a AMD Ryzen 9 5950X and a NVIDIA GeForce RTX 4090.

Pull Request: https://projects.blender.org/blender/blender/pulls/142036
2025-07-16 16:25:38 +02:00
Lukas Stockner
eaa5f63ba2 Cycles: Replace thin-film basis function approximation with accurate LUTs
Previously, we used precomputed Gaussian fits to the XYZ CMFs, performed
the spectral integration in that space, and then converted the result
to the RGB working space.

That worked because we're only supporting dielectric base layers for
the thin film code, so the inputs to the spectral integration
(reflectivity and phase) are both constant w.r.t. wavelength.

However, this will no longer work for conductive base layers.
We could handle reflectivity by converting to XYZ, but that won't work
for phase since its effect on the output is nonlinear.

Therefore, it's time to do this properly by performing the spectral
integration directly in the RGB primaries. To do this, we need to:
- Compute the RGB CMFs from the XYZ CMFs and XYZ-to-RGB matrix
- Resample the RGB CMFs to be parametrized by frequency instead of wavelength
- Compute the FFT of the CMFs
- Store it as a LUT to be used by the kernel code

However, there's two optimizations we can make:
- Both the resampling and the FFT are linear operations, as is the
  XYZ-to-RGB conversion. Therefore, we can resample and Fourier-transform
  the XYZ CMFs once, store the result in a precomputed table, and then just
  multiply the entries by the XYZ-to-RGB matrix at runtime.
  - I've included the Python script used to compute the table under
    `intern/cycles/doc/precompute`.
- The reference implementation by the paper authors [1] simply stores the
  real and imaginary parts in the LUT, and then computes
  `cos(shift)*real + sin(shift)*imag`. However, the real and imaginary parts
  are oscillating, so the LUT with linear interpolation is not particularly
  good at representing them. Instead, we can convert the table to
  Magnitude/Phase representation, which is much smoother, and do
  `mag * cos(phase - shift)` in the kernel.
  - Phase needs to be unwrapped to handle the interpolation decently,
    but that's easy.
  - This requires an extra trig operation in the kernel in the dielectric case,
    but for the conductive case we'll actually save three.

Rendered output is mostly the same, just slightly different because we're
no longer using the Gaussian approximation.

[1] "A Practical Extension to Microfacet Theory for the Modeling of
    Varying Iridescence" by Laurent Belcour and Pascal Barla,
    https://belcour.github.io/blog/research/publication/2017/05/01/brdf-thin-film.html

Pull Request: https://projects.blender.org/blender/blender/pulls/140944
2025-07-09 22:10:28 +02:00
Brecht Van Lommel
13ab5067ce Cycles: Detect volume attribute nodes that can use stochastic sampling
Detect which volume attributes nodes have a linear mapping to their usage
as density / color / temperature in volume shader nodes, and use stochastic
sampling for them.

Pull Request: https://projects.blender.org/blender/blender/pulls/132908
2025-07-09 21:04:38 +02:00
Brecht Van Lommel
646dc7fe4d Cycles: Use stochastic sampling to speed up tricubic volume filter
Stochastically turn a tricubic filter into a trilinear one. This
reduces the number of taps from 64 to 8. It combines ideas from
the "Stochastic Texture Filtering" paper and our previous GPU
sampling of 3D textures.

This is currently only used in a few places where we know stochastic
interpolation is valid or close enough in practice.
* Principled volume density, color and temperature
* Motion blur velocity

On an Macbook Pro M3 with the openvdb_smoke.blend regression test
and cubic sampling, this gives a ~2x speedup for CPU and ~4x speedup
for GPU. However it also increases noise, usually only a little. Equal
time renders for this scene show a clear reduction in noise for both
CPU and GPU.

Note we can probably get a bigger speedup with acceptable noise trade-off
using full stochastic sampling, but will investigate that separately.

Pull Request: https://projects.blender.org/blender/blender/pulls/132908
2025-07-09 21:04:38 +02:00
Brecht Van Lommel
ba5bdbcf28 Merge branch 'blender-v4.5-release' 2025-07-07 19:30:07 +02:00
Alaska
b3cc9ed21b Tests: Add intial tests for the OSL camera
This commit adds 4 tests covering the majority of the new features
added with the OSL camera feature.

Pull Request: https://projects.blender.org/blender/blender/pulls/139426
2025-07-07 19:08:44 +02:00
Alaska
7771c36270 Tests: Add tests for AOV passes on objects with transparent materials
This commit adds a test for the situation in which a AOV pass is used
on a object with a fully or semi-transparent material, either using the
transparent BSDF directly, or mixing it with some other material.

Pull Request: https://projects.blender.org/blender/blender/pulls/141068
2025-07-04 14:29:11 +02:00
Clément Foucault
b4ca7b5022 Fix: Workbench: Broken render tests after AA fix
Broken since c49e9e1773
2025-07-02 16:31:12 +02:00
Alaska
b7f1aa4a41 Tests: Add Cycles test for normal map light leaking
In a recent commit (1), light leaking was accidentally introduced on
some objects making use of normal maps (#139870)

This commit adds a test inspired by the file in that report to avoid
issues like this reoccuring in the future.

(1) a6015e1411

Pull Request: https://projects.blender.org/blender/blender/pulls/141065
2025-06-30 18:24:48 +02:00
Brecht Van Lommel
17bda2cf3f Cycles: Enable multi-bounce random walk subsurface scattering
Multi-bounce was mainly disabled for disk sampling where the probability of
hitting something is relatively low even with high albedo, but this is not so
much an issue with random walk.

This reduces darkening artifacts at the cost of some extra render time. The
difference is mainly visible when using a high radius.

Pull Request: https://projects.blender.org/blender/blender/pulls/140665
2025-06-19 20:04:49 +02:00
Lukas Stockner
49ae867de4 Fix #139870: Cycles: Some objects with normal maps leak light
This was broken by !138632, the refactor of the microfacet code to no longer
check the "geometric normal", which in reality was the smoothed normal.

Since the logic is now the same for all closure types, it seemed weird that
the light leak only affects Microfacet closures, not Diffuse.

Turns out that for diffuse closures, the relevant paths were rejected by
the initial hemisphere check in the smooth bump terminator code, which also
incorporates the smoothed but non-bump/normal-mapped normal sd->N.

So, we can detect and prevent the new light leaks by extending this check to
all closure types for the eval case. Sampling already has stricter checks,
so this doesn't apply there.

With this change, we can revert the two test cases back to their pre-refactor
version. In hindsight it was a mistake to just shrug off these changes as okay,
I should have looked closer into the difference.

Pull Request: https://projects.blender.org/blender/blender/pulls/140415
2025-06-19 19:20:06 +02:00
marcopavanello
ab21755aaf Shaders: Remove old Preetham and Hosek sky texture models
Remove old Preetham and Hosek-Wilkie sky models, which are less accurate.
The Nishita improved model has been available for long enough.

Pull Request: https://projects.blender.org/blender/blender/pulls/139923
2025-06-16 14:36:18 +02:00
Brecht Van Lommel
b920f6f1a7 Shaders: Remove point density texture node
This is replaced by geometry nodes, where volumes can now be generated from
point clouds and meshes with more control, and more efficient rendering as a
sparse volume.

No backwareds compatibility is provided, as this would be complicated, and
probably this feature was not used much in the past few years.

This node was supported in Cycles only, not by EEVEE.

Pull Request: https://projects.blender.org/blender/blender/pulls/140292
2025-06-16 12:06:02 +02:00
Clément Foucault
4fe75da973 EEVEE: Remove all remaining reference of EEVEE next
This changes the engine identifier back to `BLENDER_EEVEE`.

We keep the `BLENDER_EEVEE_NEXT` identifier around for
versioning reasons (have to detect when it is the active
engine of a older file).

This also rename a bunch of pannels that were using `next`
in their name.

This is a breaking change for Addons compatibility.

Pull Request: https://projects.blender.org/blender/blender/pulls/140282
2025-06-13 12:36:14 +02:00
Aras Pranckevicius
68111db969 Nodes: Speedup Voronoi by changing the hash function
The 2D->2D, 3D->3D, 4D->4D hash functions used in Voronoi node were
using quite an expensive hash function. Switch these to dedicated
2D/3D/4D hash functions (pcg2d, pcg3d, pcg4d) -- these are still very
good quality, but the hash function itself is 3x-4x faster.
Which makes Voronoi node calculation overall be around 2x faster. In
some cases when using OSL, the speedup is even larger.

This visibly changes output of the Voronoi noise however. The actual
noise "behaves" the same, just if someone was depending on the noise
pattern being exactly like it was before, this will change the pattern.

Images, more performance results and details wrt OSL are in the PR.

Pull Request: https://projects.blender.org/blender/blender/pulls/139520
2025-06-12 20:07:52 +02:00
Brecht Van Lommel
7f380e0644 Revert "Fix: Cycles: Do not count volume bounds bounce as transparent"
This reverts commit 23c762e388 in the
blender-v4.5-release branch to work around HIP compiler issues. It will
remain in the main branch.

Ref blender/blender#139836
2025-06-11 15:47:07 +02:00
Brecht Van Lommel
45b11a6619 Revert "Fix: Cycles: Inconsistency in transparent bounces for NEE and forward path"
This reverts commit 64dc9cc98c in the
blender-v4.5-release branch to work around HIP compiler issues. It will
remain in the main branch.

Ref blender/blender#139836
2025-06-11 15:47:07 +02:00
Brecht Van Lommel
34838a9531 Revert "Cycles: Fix inconsistency in Ng handling between Microfacets and other closures"
This reverts commit a6015e1411 in the
blender-v4.5-release branch to work around HIP compiler issues. It will
remain in the main branch.

Ref blender/blender#139836
2025-06-11 15:47:07 +02:00
Falk David
f7a0003452 Grease Pencil: Motion Blur support
This adds motion blur support for Grease Pencil.

We follow the same principle form EEVEE and use the existing
`antialiasing_accumulate` (SSAA) function to accumulate the
frames in range of the motion blur over time.

There is a new `motion_blur_steps` setting in the Grease
Pencil render settings to control the accuracy of the motion
blur. This will increase the render time.

Limitations:
* When Grease Pencil is composited into the scene, we only do
  it for one the current frame and don't take the motion blur into
  account. This will lead to hard edges currently.
* There is no viewport motion blur. This would need an entirely
  new technique that can be computed in real-time.

Pull Request: https://projects.blender.org/blender/blender/pulls/139840
2025-06-09 15:44:53 +02:00
Weizhen Huang
ee578cc738 Fix #139753: Discontinuity in mesh tangent without UV map
when there is no uv, we call the function `map_to_sphere()` to create
temporary uv for computing the tangent. It could happen that a triangle
has vertices with the u coordinates going across the line where u wraps
from 1 to 0. In this case, just computing the difference of the u
coordinates results in the wrong triangle area.

To fix this problem, we compute distance in toroidal (wrap around)
space.

This is safe for coordinates generated by `map_to_sphere()` function,
because it is not supposed to map the positions of a triangle to u
coordinates that span larger than 0.5.

Pull Request: https://projects.blender.org/blender/blender/pulls/139880
2025-06-09 13:52:00 +02:00
Brecht Van Lommel
ee619713f9 Tests: Add test files for new light features
Ref #136958, #134303
2025-05-22 16:32:44 +02:00
Eqkoss / T1NT1N
bb9d5cdaad Lights: Add normalize property
When enabled, this normalize the strength by the light area, to keep
the total output the same regardless of shape or size. This is the
existing behavior.

This is supported in Cycles, EEVEE, Hydra, USD, COLLADA.

For add-ons, an API function to compute the area is added for conversion,
in case there is no native support for normalization.

area = light.area(matrix_world=ob.matrix_world)

Co-authored-by: Brecht Van Lommel <brecht@blender.org>

Pull Request: https://projects.blender.org/blender/blender/pulls/136958
2025-05-22 16:32:44 +02:00
Brecht Van Lommel
59b4842117 Cycles: Adaptive subdivision triangular patches
There is a corner case where one side of a quad needs splitting and the other
side has only one segment. Previously this would produce either gaps or after
recent changes to stitch together geometry, uninitialized memory.

Now solve this by splitting into triangular patches, as suggested in the
DiagSplit paper. These triangular patches can be further subdivided themselves.
Dicing has special cases for 1 or 2 segments on edges. For more segments it
works the same as: quad dicing: A regular inner triangle grid stitched to the
outer edges.

Fix #136973: Inconsistent results with adaptive subdivision

Pull Request: https://projects.blender.org/blender/blender/pulls/139062
2025-05-19 12:04:11 +02:00
Lukas Stockner
a6015e1411 Cycles: Fix inconsistency in Ng handling between Microfacets and other closures
In Cycles, the convention is that reflection vs. refraction are classified
based on the hemisphere defined by the *shading* normal (N).

In general, most closure code uses the shading normal for most operations,
as is expected since using the geometric normal (Ng) would break normal maps
and smooth shading.

However, there are two places that use Ng: On the one hand, BSDF sampling
functions generally reject reflections that fall below the Ng hemisphere, since
they'd intersect the geometry when tracing the bounce. This is required, and
we can't do much about it.
On the other hand, the Microfacet evaluation code also checked that the ray
is in the same hemisphere w.r.t. both shading and geometric normal.

Theoretically, this is the right thing to do, since sampling and evaluation code
are supposed to be consistent. However, doing so breaks smooth shading, since
now direct light evaluation near the terminator will sometimes be rejected.

This didn't cause problems in practice because of another inconsistency: While
the parameter of the eval functions was named Ng, the caller actually provided
N (unclear whether by mistake or as a hacky workaround to the terminator).
When this was fixed in 063a9e89, users quickly reported issues with the shadow
terminator, so it was reverted to the hacky inconsistency in 1c50dd8b.

So, let's clean this mess up properly. If we don't want to do the Ng hemisphere
check in _eval, then instead of passing in a misleading value that ends up
making it a no-op, just remove the check. After all, the other closures don't
perform it either.

This way, we avoid the mislabeled Ng, we get rid of the special case for
microfacets, and the shadow terminator continues to be fine.

Technically, we still have the _sample vs. _eval mismatch. However, this is just
unavoidable, and is irrelevant in practice: For a strongly directional light
that makes the shadow terminator noticeable, the MIS weights will be massively
in favor of eval, to the point that it doesn't really matter what sample does.

To support this argument: You can actually reproduce a broken shadow terminator
in pretty much every Cycles version going back to 2011 by just setting up a
small intense mesh emitter, turning off MIS on it to disable _eval, and then
rendering a diffuse smooth-shaded sphere with >100000 samples so that the
fireflies resolve into somewhat consistent lighting.
If nobody has complained about this affecting all closures for 11 years,
I guess it's fine.

Pull Request: https://projects.blender.org/blender/blender/pulls/138632
2025-05-18 17:20:32 +02:00
Jesse Yurkovich
3b2bbad609 USD: Add support for Text objects during export
Similar to the existing meta-ball export, and the other exporters,
convert Text objects to meshes for export.

Ref #138883

Pull Request: https://projects.blender.org/blender/blender/pulls/138903
2025-05-16 22:12:48 +02:00