This patch adds the ability to render motion blur from Alembic caches.
The motion blur data is derived from a velocity attribute whose name has
to be defined by the user through the MeshSequenceCache modifier, with a
default value of ".velocities", which is the standard name in Alembic
for the velocity property, although other software may ignore it and
write velocity with their own naming convention (e.g. "v" in Houdini).
Furthermore, a property was added to define how the velocity vectors
are interpreted with regard to time : frame or second. "Frame"
means that the velocity is already scaled by the time step and we do not
need to modify it for it to look proper. "Second" means that the unit
the velocity was measured in is in seconds and so has to be scaled by
some time step computed here as being the time between two frames (1 /
FPS, which would be typical for a simulation). This appears to be
common, and is the default behavior.
Another property was added to control the scale of the velocity to
further modify the look of the motion blur.
Reviewed By: brecht, sybren
Differential Revision: https://developer.blender.org/D2388
Caused by c7aa0f9d74.
Since above commit, BKE_image_user_frame_calc requires an image (not
just the iuser) to get the framenumber.
Cycles used to call this with NULL image (in `image_user_file_path` and
`image_user_frame_number`), now pass the image as well.
Maniphest Tasks: T79111
Differential Revision: https://developer.blender.org/D8439
Performance is not great currently due to the API not seeming to support
efficient denoising of multiple tiles at the same time. So in many cases
only one or a few threads will actually be denoising at the same time.
In renders with many samples this is not a big problem, but for faster
renders it's a signficant overhead.
We should try to optimize this still, possibly by batching denoising of
a bigger neighborhood of multiple tiles at once.
This patch adds support for the curve primitive from OptiX to Cycles. It's currently hidden
behind a debug option, since there can be some slight rendering differences still (because no
backface culling is performed and something seems off with endcaps). The curve primitive
was added with the OptiX 7.1 SDK and requires a r450 driver or newer, so this also updates
the codebase to be able to build with the new SDK.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D8223
For historical reasons, `DupliObject::persistent_id` was of size
`2*MAX_DUPLI_RECUR`. These reasons are now gone, and the persistent ID
always gets exactly one array element for every dupli-recursion.
Differential Revision: https://developer.blender.org/D8222
Reviewed by: brecht
Compared to Optix denoise, this is usually slower since there is no GPU
acceleration. Some optimizations may still be possible, in avoid copies
to the GPU and/or denoising less often.
The main thing is that this adds viewport denoising support for computers
without an NVIDIA GPU (as long as the CPU supports SSE 4.1, which is nearly
all of them).
Ref T76259
Enabling render and viewport denoising is now both done from the render
properties. View layers still can individually be enabled/disabled for
denoising and have their own denoising parameters.
Note that the denoising engine also affects how denoising data passes are
output even if no denoising happens on the render itself, to make the passes
compatible with the engine.
This includes internal refactoring for how denoising parameters are passed
along, trying to avoid code duplication and unclear naming.
Ref T76259
This replaces the cmake options `WITH_NEW_OBJECT_TYPES` and
`WITH_NEW_SIMULATION_TYPE` with two experimental userpref settings:
* `use_new_particle_system`: Enables the point cloud type and the simulation editor.
* `use_new_hair_type`: Only displays the add-operator in the add menu for now.
Note, in the current state you can't do anything productive with the new particle
system or the new hair type. Features will be added step by step in the upcoming
weeks and months.
Reviewers: brecht
Differential Revision: https://developer.blender.org/D8096
For GPU debugging purposes, it is still possible to render with the same BVH2
on the CPU using the Debug panel in the render properties.
Note that building Blender without Embree will now lead to significantly reduced
performance in CPU rendering, and a few of the Cycles regression tests will fail
due to small pixel differences.
Ref T73778
Depends on D8014
Maniphest Tasks: T73778
Differential Revision: https://developer.blender.org/D8015
Also removing the curve system manager which only stored a few curve intersection
settings. These are all changes towards making shape and subdivision settings
per-object instead of per-scene, but there is more work to do here.
Ref T73778
Depends on D8013
Maniphest Tasks: T73778
Differential Revision: https://developer.blender.org/D8014
This keeps render results compatible for combined CPU + GPU rendering.
Peformance and quality primitives is quite different than before. There
are now two options:
* Rounded Ribbon: render hair as flat ribbon with (fake) rounded normals, for
fast rendering. Hair curves are subdivided with a fixed number of user
specified subdivisions.
This gives relatively good results, especially when used with the Principled
Hair BSDF and hair viewed from a typical distance. There are artifacts when
viewed closed up, though this was also the case with all previous primitives
(but different ones).
* 3D Curve: render hair as 3D curve, for accurate results when viewing hair
close up. This automatically subdivides the curve until it is smooth.
This gives higher quality than any of the previous primitives, but does come
at a performance cost and is somewhat slower than our previous Thick curves.
The main problem here is performance. For CPU and OpenCL rendering performance
seems usually quite close or better for similar quality results.
However for CUDA and Optix, performance of 3D curve intersection is problematic,
with e.g. 1.45x longer render time in Koro (though there is no equivalent quality
and rounded ribbons seem fine for that scene). Any help or ideas to optimize this
are welcome.
Ref T73778
Depends on D8012
Maniphest Tasks: T73778
Differential Revision: https://developer.blender.org/D8013
The hair BSDFs are already designed to assume this, and disabling backface
culling would break them in some cases.
Ref T73778
Depends on D8009
Maniphest Tasks: T73778
Differential Revision: https://developer.blender.org/D8010
Triangles were very memory intensive. The only reason they were not removed yet
is that they gave more accurate results, but there will be an accurate 3D curve
primitive added for this.
Line rendering was always poor quality since the ends do not match up. To keep CPU
and GPU compatibility we just remove them entirely. They could be brought back if
an Embree compatible implementation is added, but it's not clear to me that there
is a use case for these that we'd consider important.
Ref T73778
Reviewers: #cycles
Subscribers:
This commit adds a new model to the Sky Texture node, which is based on a
method by Nishita et al. and works by basically simulating volumetric
scattering in the atmosphere.
By making some approximations (such as only considering single scattering),
we get a fairly simple and fast simulation code that takes into account
Rayleigh and Mie scattering as well as Ozone absorption.
This code is used to precompute a 512x128 texture which is then looked up
during render time, and is fast enough to allow real-time tweaking in the
viewport.
Due to the nature of the simulation, it exposes several parameters that
allow for lots of flexibility in choosing the look and matching real-world
conditions (such as Air/Dust/Ozone density and altitude).
Additionally, the same volumetric approach can be used to compute absorption
of the direct sunlight, so the model also supports adding direct sunlight.
This makes it significantly easier to set up Sun+Sky illumination where
the direction, intensity and color of the sun actually matches the sky.
In order to support properly sampling the direct sun component, the commit
also adds logic for sampling a specific area to the kernel light sampling
code. This is combined with portal and background map sampling using MIS.
This sampling logic works for the common case of having one Sky texture
going into the Background shader, but if a custom input to the Vector
node is used or if there are multiple Sky textures, it falls back to using
only background map sampling (while automatically setting the resolution to
4096x2048 if auto resolution is used).
More infos and preview can be found here:
https://docs.google.com/document/d/1gQta0ygFWXTrl5Pmvl_nZRgUw0mWg0FJeRuNKS36m08/view
Underlying model, implementation and documentation by Marco (@nacioss).
Improvements, cleanup and sun sampling by @lukasstockner.
Differential Revision: https://developer.blender.org/D7896
With this patch Cycles recognizing when a logical OptiX and CUDA device represent the same
physical GPU and attempts to eliminate unnecessary tile copies for viewport rendering if that
is the case for all active devices. In addition, denoising is now no longer performed on the first
available OptiX device only, but instead it will try to match CUDA and OptiX
rendering/denoising devices exactly to maximize utilization.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D7975
This change modifies the multi-device implementation to support memory distribution
across devices, to reduce the overall memory footprint of large scenes and allow scenes to
fit entirely into combined GPU memory that previously had to fall back to host memory.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D7426
A new user parameter can be used to shift the shadow terminator
towards the light source. With it, one can hide some of the
artifacts that appear on coarse meshes with smooth shading.
Note that this technique is not engery conserving.
This is based on the work by the Appleseed renderer team.
Differential Revision: https://developer.blender.org/D7634
The problem was that Cycles would store a pointer to an object in
`DEGObjectIterData->templ_dupli_object`. This pointer was then accessed
when the iterator was already freed.
Reviewers: brecht
Differential Revision: https://developer.blender.org/D7797
