Support loops at the GLSL level instead of relying on
NOD_shader_nodes_inline.
This improves compilation and runtime performance, avoids causing
recompilations on iteration count changes, and allows supporting
dynamic iteration counts.
(EEVEE-only)
Pull Request: https://projects.blender.org/blender/blender/pulls/145269
The UI property was changed 7b97bc48d8
to a negative boolean but the boolean conversion inside EEVEE was
not inverted.
This mean that since 4.2, the default behavior for Lightprobe
volume has been broken / inverted.
To make an existing scene bake the same as before, all material
needs to have their `BackFace Culling > Light Probe Volume` options
inverted. This is done automatically through the versioning code.
The only test cases broken are the ones using default materials which
do not have their property turned off.
Release Notes should contains the compatibility breakage.
Pull Request: https://projects.blender.org/blender/blender/pulls/147218
Previously, Repeat Zones with non-static iterations would be fully
disconnected.
With this patch, they behave as if they have 0 iterations.
Co-authored-by: Jacques Lucke
Pull Request: https://projects.blender.org/blender/blender/pulls/147211
This implements the Menu Switch node in shader nodes. It's the same node that is
used in Geometry Nodes and the Compositor.
The Menu Switch node is purely handled during preprocessing and thus builds on
top of #141936. Hence, it's input has to be a single value, just like the
iteration count for repeat zones. This limitation can be lifted in the future,
but currently there is no way to produce a non-single menu value in shader
nodes. This will become possible if other Switch nodes are added though.
Pull Request: https://projects.blender.org/blender/blender/pulls/146896
Applies thin film iridescence to metals in Metallic BSDF and Principled BSDF.
To get the complex IOR values for each spectral band from F82 Tint colors,
the code uses the parametrization from "Artist Friendly Metallic Fresnel",
where the g parameter is set to F82. This IOR is used to find the phase shift,
but reflectance is still calculated with the F82 Tint formula after adjusting
F0 for the film's IOR.
Co-authored-by: Lukas Stockner <lukas@lukasstockner.de>
Co-authored-by: Weizhen Huang <weizhen@blender.org>
Co-authored-by: RobertMoerland <rmoerlandrj@gmail.com>
Pull Request: https://projects.blender.org/blender/blender/pulls/141131
This PR enables strip curve drawing when performing the workbench
rendertests. On Intel/vulkan the lines are to far off. Using strip will
reduce platform differences. Downside is that (basic) line rendering is not
covered anymore by a render test.
Pull Request: https://projects.blender.org/blender/blender/pulls/146820
* Add adaptive subdivision properties natively on the subdivision surface
modifier, so that other engines may reuse them in the future. This also
resolve issues where they would not get copied properly.
* Remove "Feature Set" option in the render properties, this was the last
experimental one.
* Add space choice between "Pixel" and "Object". The latter is new and can
be used for object space dicing that works with instances. Instead of
a pixel size an object space edge length is specified.
* Add object space subdivision test.
Ref #53901
Pull Request: https://projects.blender.org/blender/blender/pulls/146723
This patch removes the XY scale inputs from the Displace node. The
inputs were redundant since they were just multiplied by the vector.
This simplifies the node and improves performance slightly.
Additionally, the Vector input was renamed to Displacement since it no
longer specifies a direction.
Pull Request: https://projects.blender.org/blender/blender/pulls/146356
On its own, the main functionality of the Radial Tiling node
is the ability to divide a 2D Cartesian coordinate system into
as many radial segments as specified by the "Segments" input.
Each segment has its own affinely transformed coordinate system,
provided through the "Segment Coordinates" output, which can be
used to tile textures in a radially symmetric manner.
Additionally, a unique index is provided for every segment through
the "Segment ID" output, the width of each segment at Y-coordinate
of the "Segment Coordinates" output without normalization = 0 is
provided through the "Segment Width" output and the rotation value
of the affine transformation of the coordinate system of each segment
is provided through the "Segment Rotation" output.
The roundness of the coordinate lines of the "Segment Coordinates"
output can be controlled through the "Roundness" inputs.
This can be used to make the coordinate systems of the segments
a mix of Cartesian and polar coordinates.
Lastly, the lines of points of the "Segment Coordinates" output with
constant Y-coordinates have the shape of polygon with rounded corners,
which can be used to procedurally create rounded polygons.
Pull Request: https://projects.blender.org/blender/blender/pulls/127711
These are causing quite a big difference in existing files, which is not
easy to address in versioning. Since the goal of removing this was to
simplify things for us and that's not the case, just revert this change.
This reverts commit ab21755aaf.
Ref #139923
Pull Request: https://projects.blender.org/blender/blender/pulls/146336
This mode is based on the same athmospheric model as the previous one, but now
also accounts for multiple scattering and reflections from the ground.
This increases the accuracy, especially at low elevations.
Also renames some options for consistency:
- The previous "Nishita" model is now "Single Scattering"
- "Dust" is now "Aerosols"
- Default altitude is now 100m.
Co-authored-by: Lukas Stockner <lukas@lukasstockner.de>
Pull Request: https://projects.blender.org/blender/blender/pulls/140480
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.
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
* 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
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
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
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.
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 |  |  | N/A |
| PR |  |  |  |
| | Strand | Strip | Cylinder |
| ---- | --- | --- | --- |
| Main |  | | N/A |
| PR | ||  |
Cyclic Curve, Mixed curve type, and proper radius support:
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
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
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
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
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
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.
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
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
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
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
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
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
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
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
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
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
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
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
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
