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
Add geometry file import nodes support to the for-each-path logic.
This will make `bpy.data.file_path_map()` report the input files for
OBJ, PLY, etc. import nodes (and any other node that has a string
property of subtype `PROP_FILEPATH`).
Currently this only supports static file paths, so where the file path
is set as the input socket's default value. When the path is
determined via any noodle, this is ignored and the default value is
reported anyway.
This is necessary for the new version of Blender Asset Tracer, which
in turn is needed to resolvestudio/flamenco#104423.
Pull Request: https://projects.blender.org/blender/blender/pulls/144874
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
PR https://projects.blender.org/blender/blender/pulls/144233.
Fix#142296 performance regression caused by merging UV positions
based on face area weights, replacing it with mean average weights
computation. The former method resulted in higher probability in making
subdivision cache invalid between frame updates and thus causing expensive
recreation of blender::bke::subdiv::OpenSubdiv_Evaluator object.
While this fix isn't directly answering a question why specific UV position
updates would cause this reevaluation of subdivision object, it fixes
the performance regression caused by #139595 PR.
Found while trying to import an instanced point-instancer with the
operator setting `support_scene_instancing=false`.
The point-instancer Prototype would be partially processed but not
completely since the option was disabled. This caused a discrepancy
during the final portion of import where the view layer was synced and
we attempted to query for an object that was not present.
Pull Request: https://projects.blender.org/blender/blender/pulls/144845
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
The float buffer should be tagged with the standard untonemapped colorspace,
so that when we convert to PQ/HLG the tonemapping is preserved.
With this change:
* Using AgX highlights properly go to white.
* Using the ACES configs, we can convert EXRs to a HDR video, exactly
matching colors with the HDR video on https://dpel.aswf.io/solemates/.
Pull Request: https://projects.blender.org/blender/blender/pulls/144493
This test can't easily be updated because it relies on the old socket shape
design before #144119. Parts of it could be done from scratch again, but
most of this stuff is also tested by the new structure type inferencing test
in `bl_node_structure_type_inference.py`.
Pull Request: https://projects.blender.org/blender/blender/pulls/144185
This patch redesigns the File Output node to provide better UX and UI.
This is mainly achieved by allowing the user to create inputs by
dragging into an Extend socket and adjust existing inputs using the
familiar UI list design available in Blender. Additionally, various UI
changes were done:
- The Use Node Format option was renamed to Override Node Format for
clarity.
- Socket types are now fixed and do not change as new links are made,
allowing users to specify the exact output type and employ implicit
conversion if needed.
- The distinction between images and Multi-Layer EXR was made clearer.
- Final output paths are drawn in the UI to remove guess work.
- The Base Path was split into a Directory and a File Name.
- Panels were added to group options, include a panel for the node
format, items, and item formats.
Pull Request: https://projects.blender.org/blender/blender/pulls/141091
'exr multilayer passes' had an invalid input, so its output was updated
The rest of the tests had outdated output sockets after some 'Color'
sockets were converted into 'Vector' sockets
Pull Request: https://projects.blender.org/blender/blender/pulls/144004
Many nodes operate on all the instances that are passed into them. For example,
the Subdivision Surface node subdivides the mesh at the root but also instanced
meshes. This works well for most nodes, but there are a few nodes were the old
`modify_geometry_sets` function was not very well defined and it was tricky to
use correctly.
The fundamental problem was that the behavior is not obvious when a node creates
or modifies instances and how those are integrated with the already existing
instances.
This patch solves this with the following changes:
* Remove the old `GeometrySet::modify_geometry_sets` and related
`*_during_modify` methods.
* Add a new `blender::geometry::foreach_real_geometry` function that is similar
to the old `modify_geometry_sets` but has a more well-defined interface:
* It never passes instances into the callback. So existing instances can't be
modified with it.
* The callback is allowed to create new instances. This will automatically be
merged back with potentially already existing instances. The callback does
not have to worry about accidentally invalidating existing instances like
before.
* A few existing usages used `modify_geometry_sets` to actually modify existing
instances (usually just removing attributes). Those can't use the new
`foreach_real_geometry`, so they just get a custom simple recursive
implementation instead of using a generic function.
Pull Request: https://projects.blender.org/blender/blender/pulls/143898
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
The current glare streaks threshold for highlights is too high so the
input is just a black image, and no effects are output.
The threshold was reduced from 2.0 to 0.2 to produce a visible change.
Pull Request: https://projects.blender.org/blender/blender/pulls/142320
`node_pixelate` sets the output pixel size to 1, meaning no
transformation occurs and it is essentially the same as a single value
input. This will add a new test that pixelates the image, and renames
the original test to better reflect that edge case
Coverage:
- Function: 62.50% -> 100%
- Line: 37.36% -> 100%
- Region: 45.83% -> 100%
- Branch: 20.00% -> 90.00%
Pull Request: https://projects.blender.org/blender/blender/pulls/142438
This PR adds more markers and re-tracks them correctly on the cube clip
The output should be a gradient color, which was tested with another
setup and should mask the clip if used in conjunction with the keying
node (this PR doesn't include that setup, just the keying screen fix).
Coverage remains the same.
Pull Request: https://projects.blender.org/blender/blender/pulls/142534
* Bezier (NURBS) import, supporting both Blender and external variants.
* Cleaner Bezier export, with better results importing in Rhino.
* Internal support for exporting the new Curves type.
* Tests covering a broad number of related cases.
The current NURBS exporter writes curve data directly, without accounting
for internal padding or how knots are generated from modes. This adjusts the
export behavior to omit data that does not influence the geometry of the
curve. The result is a simplified output that is easier to parse during import,
both for the importer and when importing to other platforms (Rhino).
Visual explanation to the adjustment can be found in #139174.
Importer is also adjusted to support variations in knot patterns. Extending
it to support the data generated by the exporter and by other platforms (Rhino).
This should resolve some issues in relation to #138732.
Integrated tests are added to broadly validate the common cases generated
by the exporter, including variations of different modes and NURBS order.
Regression tests are added to validate that the NURBS generated in Rhino
are imported as expected.
More details in the PR.
Pull Request: https://projects.blender.org/blender/blender/pulls/139174
This PR removes the "Last Resort" font from the stack. Instead uses a
custom "not def" glyph, defined as an SVG file. This glyph is shown
when requesting a character not found for text inputs, text editor, and
for Sequencer text strips.
Pull Request: https://projects.blender.org/blender/blender/pulls/132032
This PR adds three tests relating to the mask node, which makes a new
mask data block for `node_mask`, creates an invalid input test,
and covers the `fixed/scene` case.
Coverage:
- Function: 88.89% -> 88.89%
- Line: 91.41% -> 94.53%
- Region: 83.33% -> 88.10%
- Branch: 62.50% -> 81.25%
Pull Request: https://projects.blender.org/blender/blender/pulls/142447
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
Originally reported for ProRes codec, but it affects multiple
other codecs: any format which is read as >= 10bit had the issue.
A regression since 93be12fde0.
The cause of the issue is that movie clip and image data-blocks
did linearization on their side, which was quite hidden to find.
Now the color management is done on the movie reader level.
Additionally, added regression test to catch such issues early
on in the future.
Pull Request: https://projects.blender.org/blender/blender/pulls/143435
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
This patch improves the realism of the Fog Glow mode of the Glare node
based on the Photopic model described in:
Physically-Based Glare Effects for Digital Images" by G. Spencer, P.
Shirley, K. Zimmerman, and D. P. Greenberg.
This is a breaking change that can't be versioned, but it is worth it
for the superior realism of the new model.
Pull Request: https://projects.blender.org/blender/blender/pulls/140646
Previously code that was reading Strip data assumed that seqbasep
and channels members would stay at fixed offsets within a struct,
forever into the future. Fix this by inferring their offsets from
the file SDNA data where needed.
Actual Strip DNA layout is not changed in this commit yet.
Co-authored-by: Sergey Sharybin <sergey@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/142940
This includes a new list structure type and socket shape, a node
to create lists, a node to retrieve values from lists, and a node to
retrieve the length of lists. It also implements multi-function support
so that function nodes work on lists.
There are three nodes included in this PR.
- **List** Creates a list of elements with a given size. The values
are computed with a field that can use the index as an input.
- **Get List Item** A field node that retrieves an element from a
a list at a given index. The index input is dynamic, so if the input
is a list, the output will be a list too.
- **List Length** Just gives the length of a list.
When a function node is used with multiple list inputs, the shorter
lists are repeated to extend it to the length of the longest.
The list nodes and structure type are hidden behind an experimental
feature until we can be sure they're useful for an actual use case.
Pull Request: https://projects.blender.org/blender/blender/pulls/140679
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
HDR video files are properly read into Blender, and can be rendered out
of Blender.
HDR video reading / decoding:
- Two flavors of HDR are recognized, based on color related video
metadata: "PQ" (Rec.2100 Perceptual Quantizer, aka SMPTE 2084) and
"HLG" (Rec.2100 Hybrid-Log-Gamma, aka ARIB STD B67). Both are read
effectively into floating point images, and their color space
transformations are done through OpenColorIO.
- The OCIO config shipped in Blender has been extended to contain
Rec.2100-PQ and Rec.2100-HLG color spaces.
- Note that if you already had a HDR video in sequencer or movie clip,
it would have looked "incorrect" previously, and it will continue to
look incorrect, since it already has "wrong" color space assigned to
it. Either re-add it (which should assign the correct color space),
or manually change the color space to PQ or HLG one as needed.
HDR video writing / encoding"
- For H.265 and AV1 the video encoding options now display the HDR mode.
Similar to reading, there are PQ and HLG HDR mode options.
- Reference white is assumed to be 100 nits.
- YUV uses "full" ("PC/jpeg") color range.
- No mastering display metadata is written into the video file, since
generally that information is not known inside Blender.
More details and screenshots in the PR.
Co-authored-by: Sergey Sharybin <sergey@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/120033
Need to ensure that interpolation between neighboring quaternions
takes the shortest path. The Python FBX importer was doing this;
due to oversight was missed in the new importer.
Pull Request: https://projects.blender.org/blender/blender/pulls/142659
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
This fixes the anonymous attribute lifetime inferencing for the closure zone and
the evaluate closure node. It also adds new regression tests for cases where a
closure outputs a field.
Pull Request: https://projects.blender.org/blender/blender/pulls/141925
This fixes 4 bugs all conspiring to make the referenced SubD scenario
quite broken:
- When manually creating a MeshSequenceCache, the reading of edge and
vertex crease data was skipped. Fixed by reading crease data inside
the common `read_mesh` method.
- When importing an Alembic with animated edge or vertex crease data, a
MeshSequenceCache modifier was not being added to the object. This was
due to not checking the relevant crease properties and required adding
a specialized `has_animations` function.
- When importing animated vertex crease data, a duplicate `vertex_crease`
attribute would be created, breaking the animation. Fixed by using the
attribute API rather than custom data.
- The MeshSequenceCache scenario would call into the Alembic Mesh reader
which ended up referencing deallocated stack memory for the
ImportSettings. In release builds this would cause sporadic failures
because the value of `blender_archive_version_prior_44` would be
random. There was already a very old TODO for this and we finally
really needed to address it.
A new test was added which exports animated creases on two meshes and
re-imports them back in. It verifies that each mesh gets a
MeshSequenceCache modifier added and also ensures the values of the
creases are correct for all frames.
Pull Request: https://projects.blender.org/blender/blender/pulls/141646
These two tests cover the extended boundary option for the blur node.
One with single value input and another with variable input.
They mirror the non-extended gaussian tests.
Coverage:
- Function: 86.36% -> 90.91%
- Line: 91.95% -> 96.90%
- Region: 83.51% -> 96.63%
- Branch: 84.00% -> 95.65%
Pull Request: https://projects.blender.org/blender/blender/pulls/141528
In this report, adding the "resolution" attribute didn't clear the
evaluated positions cache. In some cases capturing an attribute on
the mesh might just add the mesh rather than using an attribute
writer.
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
