This was added for a fairly specialezed use case and is no longer being used
as far as we know. A future replacement would be to add a USD/Hydra procedural,
for which most of the groundwork already exists.
Pull Request: https://projects.blender.org/blender/blender/pulls/146021
`world_use_portal` is not needed anymore, now that we always add world
as object (b20b4218d5).
We now check if background light is enabled only in
`test_enabled_lights()`, depending on the sample settings.
Pull Request: https://projects.blender.org/blender/blender/pulls/144710
This implement the design detailed in #135935.
A new per object property called `Shadow Terminator Normal Offset` is
introduced to shift the shadowed position along the shading normal.
The amount of shift is defined in object space on the object datablock.
This amount is modulated by the facing ratio to the light. Faces
already facing the light will get no offset. This avoids most light
leaking artifacts.
In case of multiple shading normal, the normal used for the shift
is arbitrary. Note that this is the same behavior for other biases.
The magnitude of the bias is controlled by `Shadow Terminator Normal Offset`.
The amount of faces affected by the bias is controlled using
`Shadow Terminator Geometry Offset` just like cycles.
Tweaking the `Shadow Terminator Geometry Offset` allows to avoid too much
shadow distortion on surfaces with bump mapping.
Cycles properties are copied from the Cycles object datablock to the
blender datablock. This break the python API for Cycles.
The defaults are set to no bias because:
- There is no good default. The best value depends on the geometry.
- The best value might depend on real-time displacement.
- Any bias will introduce light leaking on surfaces that do not need it.
- There is an additional cost of enabling it, which is proportional
to the amount of pixels on screen using it.
Pull Request: https://projects.blender.org/blender/blender/pulls/136935
The object was not properly tagged for update when syncing object motion
blur transforms. This caused issue with the camera in volume test after
recent scene update refactoring in 86b67a20d6, but potentially also
other ones.
Pull Request: https://projects.blender.org/blender/blender/pulls/137930
Use the mesh wrapper mechanism from GPU subdivision to get the base mesh.
This can significantly reduce memory usage and render setup time if the
level was not manually set to zero.
Pull Request: https://projects.blender.org/blender/blender/pulls/135895
This is an intermediate steps towards making lights actual geometry.
Light is now a subclass of Geometry, which simplifies some code.
The geometry is not added to the BVH yet, which would be the next
step and improve light intersection performance with many lights.
This makes object attributes work on lights.
Co-authored-by: Lukas Stockner <lukas@lukasstockner.de>
Pull Request: https://projects.blender.org/blender/blender/pulls/134846
The issue here is that motion_steps handling is a bit complex, and the
parallel synchronization of geometry does not play well with it.
The obvious result of this was a crash related to the main thread
checking attributes while the geometry sync was changing them, but
there was also another race condition that could result in ending up
with the wrong motion_steps.
Specific changes:
- Change place where `motion_steps` is set to avoid concurrent access
- Change the default `motion_steps` to zero, since they won't be
explicitly set if there's no motion now
- Don't skip `motion_steps` copy in `sync_X` since it's no longer set
in `sync_object` and we need to transfer the value in case it was set
to 3 by the velocity code since that's no longer the default
Pull Request: https://projects.blender.org/blender/blender/pulls/133669
Check was misc-const-correctness, combined with readability-isolate-declaration
as suggested by the docs.
Temporarily clang-format "QualifierAlignment: Left" was used to get consistency
with the prevailing order of keywords.
Pull Request: https://projects.blender.org/blender/blender/pulls/132361
* Use .empty() and .data()
* Use nullptr instead of 0
* No else after return
* Simple class member initialization
* Add override for virtual methods
* Include C++ instead of C headers
* Remove some unused includes
* Use default constructors
* Always use braces
* Consistent names in definition and declaration
* Change typedef to using
Pull Request: https://projects.blender.org/blender/blender/pulls/132361
In this case the object transform can use more motion steps, but the
geometry needs to have its motion steps fixed since the velocity
attribute completely overrides them.
With this change, instances of lamps and emissive meshes which do not
have their own light group assigned will use the light group of the
collection instance.
If an object does have a light group assigned, its instances will
continue to use it regardless of the collection instance's light group.
The attribute node already allows accessing attributes associated
with objects and meshes, which allows changing the behavior of the
same material between different objects or instances. The same idea
can be extended to an even more global level of layers and scenes.
Currently view layers provide an option to replace all materials
with a different one. However, since the same material will be applied
to all objects in the layer, varying the behavior between layers while
preserving distinct materials requires duplicating objects.
Providing access to properties of layers and scenes via the attribute
node enables making materials with built-in switches or settings that
can be controlled globally at the view layer level. This is probably
most useful for complex NPR shading and compositing. Like with objects,
the node can also access built-in scene properties, like render resolution
or FOV of the active camera. Lookup is also attempted in World, similar
to how the Object mode checks the Mesh datablock.
In Cycles this mode is implemented by replacing the attribute node with
the attribute value during sync, allowing constant folding to take the
values into account. This means however that materials that use this
feature have to be re-synced upon any changes to scene, world or camera.
The Eevee version uses a new uniform buffer containing a sorted array
mapping name hashes to values, with binary search lookup. The array
is limited to 512 entries, which is effectively limitless even
considering it is shared by all materials in the scene; it is also
just 16KB of memory so no point trying to optimize further.
The buffer has to be rebuilt when new attributes are detected in a
material, so the draw engine keeps a table of recently seen attribute
names to minimize the chance of extra rebuilds mid-draw.
Differential Revision: https://developer.blender.org/D15941
Currently lookup of Object and Instancer attributes is completely
duplicated between Cycles, Eevee and Eevee Next. This is bad design,
so this patch aims to deduplicate it by introducing a common API
in blenkernel.
In case of Cycles this requires certain hacks, but according to
Brecht it is planned to be rewritten later for more direct access
to internal Blender data anyway.
Differential Revision: https://developer.blender.org/D16117
With the ultimate goal of simplifying drawing and evaluation,
this patch makes the following changes and removes code:
- Use `Mesh` instead of `DispList` for evaluated basis metaballs.
- Remove all `DispList` drawing code, which is now unused.
- Simplify code that converts evaluated metaballs to meshes.
- Store the evaluated mesh in the evaluated geometry set.
This has the following indirect benefits:
- Evaluated meshes from metaball objects can be used in geometry nodes.
- Renderers can ignore evaluated metaball objects completely
- Cycles rendering no longer has to convert to mesh from `DispList`.
- We get closer to removing `DispList` completely.
- Optimizations to mesh rendering will also apply to metaball objects.
The vertex normals on the evaluated mesh are technically invalid;
the regular calculation wouldn't reproduce them. Metaball objects
don't support modifiers though, so it shouldn't be a problem.
Eventually we can support per-vertex custom normals (T93551).
Differential Revision: https://developer.blender.org/D14593
This adds support for rendering motion blur for volumes, using their
velocity field. This works for fluid simulations and imported VDB
volumes. For the latter, the name of the velocity field can be set per
volume object, with automatic detection of velocity fields that are
split into 3 scalar grids.
A new parameter is also added to scale velocity for more artistic control.
Like for Alembic and USD caches, a parameter to set the unit of time in
which the velocity vectors are expressed is also added. For Blender gas
simulations, the velocity unit should always be in seconds, so this is
only exposed for volume objects which may come from external OpenVDB
files.
These parameters are available under the `Render` panels for the fluid
domain and the volume object data properties respectively.
Credits: kernel advection code from Tangent Animation's Blackbird based
on earlier work by Geraldine Chua
Differential Revision: https://developer.blender.org/D14629
This commit furthers some of the changes that were started in
rBb9febb54a492 and subsequent commits by changing the way surface
objects are presented to render engines and other users of evaluated
objects in the same way. Instead of presenting evaluated surface objects
as an `OB_SURF` object with an evaluated mesh, `OB_SURF` objects
can now have an evaluated geometry set, which uses the same system
as other object types to deal with multi-type evaluated data.
This clarification makes it more obvious that lots of code that dealt
with the `DispList` type isn't used. It wasn't before either, now it's
just *by design*. Over 1100 lines can be removed. The legacy curve
draw cache code is much simpler now too. The idea behind the further
removal of `DispList` is that it's better to focus optimization efforts
on a single mesh data structure.
One expected functional change is that the evaluated mesh from surface
objects can now be used in geometry nodes with the object info node.
Cycles and the OBJ IO tests had to be tweaked to avoid using evaluated
surface objects instead of the newly exposed mesh objects.
Differential Revision: https://developer.blender.org/D14550
Light groups are a type of pass that only contains lighting from a subset of light sources.
They are created in the View layer, and light sources (lamps, objects with emissive materials
and/or the environment) can be assigned to a group.
Currently, each light group ends up generating its own version of the Combined pass.
In the future, additional types of passes (e.g. shadowcatcher) might be getting their own
per-lightgroup versions.
The lightgroup creation and assignment is not Cycles-specific, so Eevee or external render
engines could make use of it in the future.
Note that Lightgroups are identified by their name - therefore, the name of the Lightgroup
in the View Layer and the name that's set in an object's settings must match for it to be
included.
Currently, changing a Lightgroup's name does not update objects - this is planned for the
future, along with other features such as denoising for light groups and viewing them in
preview renders.
Original patch by Alex Fuller (@mistaed), with some polishing by Lukas Stockner (@lukasstockner97).
Differential Revision: https://developer.blender.org/D12871
This adds support for selective rendering of caustics in shadows of refractive
objects. Example uses are rendering of underwater caustics and eye caustics.
This is based on "Manifold Next Event Estimation", a method developed for
production rendering. The idea is to selectively enable shadow caustics on a
few objects in the scene where they have a big visual impact, without impacting
render performance for the rest of the scene.
The Shadow Caustic option must be manually enabled on light, caustic receiver
and caster objects. For such light paths, the Filter Glossy option will be
ignored and replaced by sharp caustics.
Currently this method has a various limitations:
* Only caustics in shadows of refractive objects work, which means no caustics
from reflection or caustics that outside shadows. Only up to 4 refractive
caustic bounces are supported.
* Caustic caster objects should have smooth normals.
* Not currently support for Metal GPU rendering.
In the future this method may be extended for more general caustics.
TECHNICAL DETAILS
This code adds manifold next event estimation through refractive surface(s) as a
new sampling technique for direct lighting, i.e. finding the point on the
refractive surface(s) along the path to a light sample, which satisfies Fermat's
principle for a given microfacet normal and the path's end points. This
technique involves walking on the "specular manifold" using a pseudo newton
solver. Such a manifold is defined by the specular constraint matrix from the
manifold exploration framework [2]. For each refractive interface, this
constraint is defined by enforcing that the generalized half-vector projection
onto the interface local tangent plane is null. The newton solver guides the
walk by linearizing the manifold locally before reprojecting the linear solution
onto the refractive surface. See paper [1] for more details about the technique
itself and [3] for the half-vector light transport formulation, from which it is
derived.
[1] Manifold Next Event Estimation
Johannes Hanika, Marc Droske, and Luca Fascione. 2015.
Comput. Graph. Forum 34, 4 (July 2015), 87–97.
https://jo.dreggn.org/home/2015_mnee.pdf
[2] Manifold exploration: a Markov Chain Monte Carlo technique for rendering
scenes with difficult specular transport Wenzel Jakob and Steve Marschner.
2012. ACM Trans. Graph. 31, 4, Article 58 (July 2012), 13 pages.
https://www.cs.cornell.edu/projects/manifolds-sg12/
[3] The Natural-Constraint Representation of the Path Space for Efficient
Light Transport Simulation. Anton S. Kaplanyan, Johannes Hanika, and Carsten
Dachsbacher. 2014. ACM Trans. Graph. 33, 4, Article 102 (July 2014), 13 pages.
https://cg.ivd.kit.edu/english/HSLT.php
The code for this samping technique was inserted at the light sampling stage
(direct lighting). If the walk is successful, it turns off path regularization
using a specialized flag in the path state (PATH_MNEE_SUCCESS). This flag tells
the integrator not to blur the brdf roughness further down the path (in a child
ray created from BSDF sampling). In addition, using a cascading mechanism of
flag values, we cull connections to caustic lights for this and children rays,
which should be resolved through MNEE.
This mechanism also cancels the MIS bsdf counter part at the casutic receiver
depth, in essence leaving MNEE as the only sampling technique from receivers
through refractive casters to caustic lights. This choice might not be optimal
when the light gets large wrt to the receiver, though this is usually not when
you want to use MNEE.
This connection culling strategy removes a fair amount of fireflies, at the cost
of introducing a slight bias. Because of the selective nature of the culling
mechanism, reflective caustics still benefit from the native path
regularization, which further removes fireflies on other surfaces (bouncing
light off casters).
Differential Revision: https://developer.blender.org/D13533
The Alembic procedural was only enabled during viewport renders
originally because it did not have any caching strategy. Now that
is does, we can allow its usage in final renders.
This also removes the `dag_eval_mode` argument passing to
`ModifierTypeInfo.dependsOnTime` which was originally added to detect if
we are doing a viewport render for enabling the procedural.
Differential Revision: https://developer.blender.org/D14520
An alpha component can be specified for an object's color. This adds an alpha
socket to the object info shader node allowing for the alpha component of the
object's color to be accessed in the shader editor.
Differential Revision: https://developer.blender.org/D14141
* Replace license text in headers with SPDX identifiers.
* Remove specific license info from outdated readme.txt, instead leave details
to the source files.
* Add list of SPDX license identifiers used, and corresponding license texts.
* Update copyright dates while we're at it.
Ref D14069, T95597
Based on discussions from T95355 and T94193, the plan is to use
the name "Curves" to describe the data-block container for multiple
curves. Eventually this will replace the existing "Curve" data-block.
However, it will be a while before the curve data-block can be replaced
so in order to distinguish the two curve types in the UI, "Hair Curves"
will be used, but eventually changed back to "Curves".
This patch renames "hair-related" files, functions, types, and variable
names to this convention. A deep rename is preferred to keep code
consistent and to avoid any "hair" terminology from leaking, since the
new data-block is meant for all curve types, not just hair use cases.
The downside of this naming is that the difference between "Curve"
and "Curves" has become important. That was considered during
design discussons and deemed acceptable, especially given the
non-permanent nature of the somewhat common conflict.
Some points of interest:
- All DNA compatibility is lost, just like rBf59767ff9729.
- I renamed `ID_HA` to `ID_CV` so there is no complete mismatch.
- `hair_curves` is used where necessary to distinguish from the
existing "curves" plural.
- I didn't rename any of the cycles/rendering code function names,
since that is also used by the old hair particle system.
Differential Revision: https://developer.blender.org/D14007
Override layers are a standard feature of Alembic, where archives can override
data from other archives, provided that the hierarchies match.
This is useful for modifying a UV map, updating an animation, or even creating
some sort of LOD system where low resolution meshes are swapped by high resolution
versions.
It is possible to add UV maps and vertex colors using this system, however, they
will only appear in the spreadsheet editor when viewing evaluated data, as the UV
map and Vertex color UI only show data present on the original mesh.
Implementation wise, this adds a `CacheFileLayer` data structure to the `CacheFile`
DNA, as well as some operators and UI to present and manage the layers. For both
the Alembic importer and the Cycles procedural, the main change is creating an
archive from a list of filepaths, instead of a single one.
After importing the base file through the regular import operator, layers can be added
to or removed from the `CacheFile` via the UI list under the `Override Layers` panel
located in the Mesh Sequence Cache modifier. Layers can also be moved around or
hidden.
See differential page for tests files and demos.
Reviewed by: brecht, sybren
Differential Revision: https://developer.blender.org/D13603
This add support for rendering of the point cloud object in Blender, as a native
geometry type in Cycles that is more memory and time efficient than instancing
sphere meshes. This can be useful for rendering sand, water splashes, particles,
motion graphics, etc.
Points are currently always rendered as spheres, with backface culling. More
shapes are likely to be added later, but this is the most important one and can
be customized with shaders.
For CPU rendering the Embree primitive is used, for GPU there is our own
intersection code. Motion blur is suppored. Volumes inside points are not
currently supported.
Implemented with help from:
* Kévin Dietrich: Alembic procedural integration
* Patrick Mourse: OptiX integration
* Josh Whelchel: update for cycles-x changes
Ref T92573
Differential Revision: https://developer.blender.org/D9887
The issue was that the `object_is_geometry` method was used in two different
contexts that expected the function to behave differently. So a recent change
that fixed `object_is_geometry` for one context, broke it for the other context.
The two contexts are:
* Check if a "real" object can contain a geometry to check if it has to be tagged
for sync after an update.
* Check if an object/instance actually is a geometry that cycles can work with.
I created a new `object_can_have_geometry` method for the first use case, instead
of trying to adapt the existing object_is_geometry method to serve both uses.
Additionally, I changed it so that a BObjectInfo is passed into `object_is_geometry`
to make it more explicit when this method is supposed to be used.
Differential Revision: https://developer.blender.org/D13135
Evaluated meshes from curves are presented to render engines as
separate instance objects now, just like evaluated meshes from other
object types like point clouds and volumes. For that reason, cycles
should not consider curve objects as geometry (previously it did,
meaning it retrieved a second mesh from the curve object as well
as the temporary evaluated mesh geometry).
Further, avoid adding a curve object's evaluated mesh as data_eval,
since that is special behavior for meshes that is arbitrary. Adding an
evaluated mesh there but not an evalauted pointcloud is arbitrary,
for example. Retrieve the evaluated mesh in from the geometry set
in BKE_object_get_evaluated_mesh now, to support that change.
This gets us closer to a place where all of an object's evaluated data
is stored in geometry_set_eval, and we just have helper functions
to access specific geometry components.
Differential Revision: https://developer.blender.org/D13118
