37 Commits

Author SHA1 Message Date
Brecht Van Lommel
689f182792 Cycles: Make adaptive subdivision a non-experimental feature
* 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
2025-09-25 16:18:50 +02:00
Brecht Van Lommel
2193096106 Cycles: Change normal map node to work with undisplaced normal and tangent
This fits better with the way normal and displacement maps are typically
combined. Previously there was a mixing of displaced normal and undisplaced
tangent, which was broken behavior.

Additionally, to undisplaced_N and undisplaced_tangent attributes must now
always be used to get undisplaced coordinates. The regular N and tangent
attributes now always include displacement.

Ref #142022

Pull Request: https://projects.blender.org/blender/blender/pulls/143109
2025-08-11 12:08:12 +02:00
Brecht Van Lommel
47f9b7a98e Fix #142022: Cycles undisplaced normal not available
Previously with adaptive subdivision this happened to work with the N
attribute, but that was not meant to be undisplaced. This adds a new
undisplaced_N attribute specifically for this purpose.

For backwards compatibility in Blender 4.5, this also keeps N undisplaced.
But that will be changed in 5.0.

Pull Request: https://projects.blender.org/blender/blender/pulls/142090
2025-07-24 18:16:25 +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
358de9e6c9 Fix #139010: Cycles USD motion blur shading artifacts
This code should not have been removed in 47e1b24c29.
2025-05-19 12:12:46 +02:00
Alex Fuller
a1b7ce1d22 Cycles: Move UV tangent computation into the core
This makes it available in Cycles standalone, and the implementation
can be shared with Blender. This also makes it possible to compute
tangents after tessellation for adaptive subdivision.

There is a difference in UV map tangents when there are no UVs. They
are now generated from object space coordinates instead of auto
texture space coordinates. This is more efficient, and a corner case
that we don't have to keep compatible.

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

Pull Request: https://projects.blender.org/blender/cycles/pulls/25
2025-03-27 22:07:50 +01:00
Brecht Van Lommel
47e1b24c29 Refactor: Cycles: Apply static transforms later in scene update
It makes more sense to do it after geometry processing, in particular
for the tangent computation that is coming.

Pull Request: https://projects.blender.org/blender/blender/pulls/136576
2025-03-27 22:07:50 +01:00
Brecht Van Lommel
c448bf16e5 Cycles: Multithread adaptive subdivision dicing
* Perform attribute interpolation as part of dicing.
* Remove temporary subd uv and face index attributes.

On a MacBook M3 with 12 P-cores and 4 E-cores, these changes overall give
a 10x-14x speedup on various scenes. Note that splitting is still single
threaded and can be expensive, and UV subdivision can be optimized more.

Pull Request: https://projects.blender.org/blender/blender/pulls/136411
2025-03-24 09:42:47 +01:00
Brecht Van Lommel
de821416c7 Cycles: Adaptive subdivision dicing and splitting improvements
* Share vertices between patches instead of using stitch map
* Switch to OpenSubdiv compatible counter-clockwise indexing
* Simplify patch edge reverse direction logic
* Add more comments to splitting and dicing

Pull Request: https://projects.blender.org/blender/blender/pulls/135681
2025-03-11 20:58:33 +01:00
Brecht Van Lommel
42846caca1 Cycles: Adaptive subdivision support for modifier options
* Use creases
* Boundary interpolation
* UV interpolation

Pull Request: https://projects.blender.org/blender/blender/pulls/135681
2025-03-11 20:58:17 +01:00
Brecht Van Lommel
82751ca10c Cycles: Adaptive subdivision motion blur support
* Smooth interpolation of vertex coordinates and normals of motion steps
* Fix issues with Blender sync and object device update

Pull Request: https://projects.blender.org/blender/blender/pulls/135681
2025-03-11 20:58:14 +01:00
Brecht Van Lommel
07b60c189b Cycles: Perform attribute subdivision on the host side
* Add SubdAttributeInterpolation class for linear attribute interpolation.
* Dicing computes ptex UV and face ID for interpolation.
* Simplify mesh storage of subd primitive counts
* Remove kernel code for subd attribute interpolation
* Remove patch table packing and upload

The old optimization adds a fair amount of complexity to the kernel, affecting
performance even when not using the feature. It's also not that useful as it
does not work for UVs that needs special interpolation. With this simpler code
it should be easier to make it feature complete.

Pull Request: https://projects.blender.org/blender/blender/pulls/135681
2025-03-11 20:58:07 +01:00
Brecht Van Lommel
6ec541ca4e Refactor: Cycles: Remove face normal attribute
It's already computed on demand in the kernel, no need to have it host side.

Pull Request: https://projects.blender.org/blender/blender/pulls/135681
2025-03-11 20:57:51 +01:00
Brecht Van Lommel
9971648783 Refactor: Cycles: Replace new/delete by unique_ptr, in simple cases
Pull Request: https://projects.blender.org/blender/blender/pulls/132361
2025-01-03 10:23:30 +01:00
Brecht Van Lommel
57ff24cb99 Refactor: Cycles: Add const keyword to more function parameters
Pull Request: https://projects.blender.org/blender/blender/pulls/132361
2025-01-03 10:23:24 +01:00
Brecht Van Lommel
dd51c8660b Refactor: Cycles: Add const keyword where possible, using clang-tidy
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
2025-01-03 10:23:20 +01:00
Brecht Van Lommel
689633d802 Refactor: Cycles: Avoid unsafe memcpy and memcmp
Pull Request: https://projects.blender.org/blender/blender/pulls/132361
2025-01-03 10:23:15 +01:00
Brecht Van Lommel
60bec183cb Refactor: Cycles: Replace foreach() by range based for loops
Pull Request: https://projects.blender.org/blender/blender/pulls/132361
2025-01-03 10:23:05 +01:00
Brecht Van Lommel
d0c2e68e5f Refactor: Cycles: Automated clang-tidy fixups in Cycles
* 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
2025-01-03 10:22:55 +01:00
Brecht Van Lommel
3c2a6fbb9c Refactor: Cycles: Use nullptr instead of NULL
Pull Request: https://projects.blender.org/blender/blender/pulls/132361
2025-01-03 10:22:43 +01:00
Campbell Barton
5b9740c913 Cleanup: use braces for sources in intern/
Omitted intern/itasc as some of these sources are from KDL:
https://www.orocos.org/kdl.html
2023-09-17 09:05:40 +10:00
Campbell Barton
c12994612b License headers: use SPDX-FileCopyrightText in intern/cycles 2023-06-14 16:53:23 +10:00
Sergey Sharybin
d32d787f5f Clang-Format: Allow empty functions to be single-line
For example

```
OIIOOutputDriver::~OIIOOutputDriver()
{
}
```

becomes

```
OIIOOutputDriver::~OIIOOutputDriver() {}
```

Saves quite some vertical space, which is especially handy for
constructors.

Pull Request: https://projects.blender.org/blender/blender/pulls/105594
2023-03-29 16:50:54 +02:00
Campbell Barton
f240a16037 Cleanup: format 2023-02-27 21:34:53 +11:00
William Leeson
6c03339e48 Cycles: reduce mesh memory usage by unflattening
To improve mesh upload speeds and reduce the size of the scene data which allows larger scenes to be rendered.

The meshes in Cycles are currently stored as flattened meshes, where each triangle is stored as a set of 3 vertices. Unflattening writes out the vertices in a list according to the index buffer. This uses a lot of memory and for current hardware does not provide a noticeable benefit. This change unflattens the mesh by directly using the meshes vertex and index buffers directly and skips the unflattening. This change allows for larger scenes and also a reduction in the sizes of the meshes. Further it results in a decrease the amount of time it takes to upload the data to a GPU. This is especially important for when multiple GPUs are used in a single machine.

Pull Request #105173
2023-02-27 10:39:19 +01:00
Andrii Symkin
c2a2f3553a Cycles: unify math functions names
This patch unifies the names of math functions for different data types and uses
overloading instead. The goal is to make it possible to swap out all the float3
variables containing RGB data with something else, with as few as possible
changes to the code. It's a requirement for future spectral rendering patches.

Differential Revision: https://developer.blender.org/D15276
2022-06-23 15:02:53 +02:00
Charles Flèche
b6eb7dae59 Fix Cycles missing nullptr check in case mesh has no shader
Did not affect Blender, but could happen with other integrations.

Differential Revision: https://developer.blender.org/D14538
2022-04-11 14:24:59 +02:00
Patrick Mours
d350976ba0 Cycles: Add Hydra render delegate
This patch adds a Hydra render delegate to Cycles, allowing Cycles to be used for rendering
in applications that provide a Hydra viewport. The implementation was written from scratch
against Cycles X, for integration into the Blender repository to make it possible to continue
developing it in step with the rest of Cycles. For this purpose it follows the style of the rest of
the Cycles code and can be built with a CMake option
(`WITH_CYCLES_HYDRA_RENDER_DELEGATE=1`) similar to the existing standalone version
of Cycles.

Since Hydra render delegates need to be built against the exact USD version and other
dependencies as the target application is using, this is intended to be built separate from
Blender (`WITH_BLENDER=0` CMake option) and with support for library versions different
from what Blender is using. As such the CMake build scripts for Windows had to be modified
slightly, so that the Cycles Hydra render delegate can e.g. be built with MSVC 2017 again
even though Blender requires MSVC 2019 now, and it's possible to specify custom paths to
the USD SDK etc. The codebase supports building against the latest USD release 22.03 and all
the way back to USD 20.08 (with some limitations).

Reviewed By: brecht, LazyDodo

Differential Revision: https://developer.blender.org/D14398
2022-03-23 16:39:05 +01:00
Campbell Barton
1829232598 Cleanup: spelling in comments & some minor clarifications 2022-03-10 16:27:18 +11:00
Brecht Van Lommel
9cfc7967dd Cycles: use SPDX license headers
* 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
2022-02-11 17:47:34 +01:00
Sergey Sharybin
04d55038ee Fix size_t -> int -> size_t round trip in Cycles
There are two things achieved by this change:

- No possible downcast of size_t to int when calculating motion steps.
- Disambiguate call to `min()` which was for some reason considered
  ambiguous on 32bit platforms `min(int, unsigned int)`.
- Do the same for the `max()` call to keep them symmetrical.

On an implementation side the `min()` is defined for a fixed width
integer type to disambiguate uint from size_t on 32bit platforms,
and yet be able to use it for 32bit operands on 64bit platforms without
upcast.

This ended up in a bit bigger change as the conditional compile-in of
functions is easiest if the functions is templated. Making the functions
templated required to remove the other source of ambiguity which is
`algorithm.h` which was pulling min/max from std.

Now it is the `math.h` which is the source of truth for min/max.
It was only one place which was relying on `algorithm.h` for these
functions, hence the choice of `math.h` as the safest and least
intrusive.

Fixes 32bit platforms (such as i386) in Debian package build system.

Differential Revision: https://developer.blender.org/D14062
2022-02-10 12:39:41 +01:00
Sergey Sharybin
c69ee218d7 Revert "Fix size_t -> int -> size_t round trip in Cycles"
This reverts commit d74bb7be19.

Need to re-iterate to have a proper support of all platforms.
2022-02-09 16:16:21 +01:00
Sergey Sharybin
d74bb7be19 Fix size_t -> int -> size_t round trip in Cycles
There are two things achieved by this change:

- No possible downcast of size_t to int when calculating motion steps.
- Disambiguate call to min() which was for some reason considered
  ambiguous on 32bit platforms `min(int, unsigned int)`.

On an implementation side the `min()` is defined for a fixed width
integer type to disambiguate uint from size_t on 32bit platforms,
and yet be able to use it for 32bit operands on 64bit platforms without
upcast.

Fixes 32bit platforms (such as i386) in Debian package build system.

Differential Revision: https://developer.blender.org/D13992
2022-02-09 14:45:39 +01:00
Kévin Dietrich
4425e0cd64 Subdivision: add support for vertex creasing
This adds vertex creasing support for OpenSubDiv for modeling, rendering,
Alembic and USD I/O.

For modeling, vertex creasing follows the edge creasing implementation with an
operator accessible through the Vertex menu in Edit Mode, and some parameter in
the properties panel. The option in the Subsurf and Multires to use edge
creasing also affects vertex creasing.

The vertex crease data is stored as a CustomData layer, unlike edge creases
which for now are stored in `MEdge`, but will in the future also be moved to
a `CustomData` layer. See comments for details on the difference in behavior
for the `CD_CREASE` layer between egdes and vertices.

For Cycles this adds sockets on the Mesh node to hold data about which vertices
are creased (one socket for the indices, one for the weigths).

Viewport rendering of vertex creasing reuses the same color scheme as for edges
and creased vertices are drawn bigger than uncreased vertices.

For Alembic and USD, vertex crease support follows the edge crease
implementation, they are always read, but only exported if a `Subsurf` modifier
is present on the Mesh.

Reviewed By: brecht, fclem, sergey, sybren, campbellbarton

Differential Revision: https://developer.blender.org/D10145
2022-01-20 12:21:34 +01:00
Brecht Van Lommel
063ad8635e Cycles: reduce triangle memory usage with packed_float3
Depends on D13243

Differential Revision: https://developer.blender.org/D13244
2021-11-17 17:29:41 +01:00
Brecht Van Lommel
fd25e883e2 Cycles: remove prefix from source code file names
Remove prefix of filenames that is the same as the folder name. This used
to help when #includes were using individual files, but now they are always
relative to the cycles root directory and so the prefixes are redundant.

For patches and branches, git merge and rebase should be able to detect the
renames and move over code to the right file.
2021-10-26 15:37:04 +02:00
Brecht Van Lommel
d7d40745fa Cycles: changes to source code folders structure
* Split render/ into scene/ and session/. The scene/ folder now contains the
  scene and its nodes. The session/ folder contains the render session and
  associated data structures like drivers and render buffers.
* Move top level kernel headers into new folders kernel/camera/, kernel/film/,
  kernel/light/, kernel/sample/, kernel/util/
* Move integrator related kernel headers into kernel/integrator/
* Move OSL shaders from kernel/shaders/ to kernel/osl/shaders/

For patches and branches, git merge and rebase should be able to detect the
renames and move over code to the right file.
2021-10-26 15:36:39 +02:00