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
Regression in 265d97556aa0f0f2a0e4dd7584e3b8573bbddd54.
Where iterating directly on a property group failed, e.g.:
`iter(group)`, tests missed this since only `group.keys()`
was checked.
The build-bot directly referenced this file and doesn't
have publically available configuration.
Add an empty file until this can be removed by the build scripts.
Use a shorter/simpler license convention, stops the header taking so
much space.
Follow the SPDX license specification: https://spdx.org/licenses
- C/C++/objc/objc++
- Python
- Shell Scripts
- CMake, GNUmakefile
While most of the source tree has been included
- `./extern/` was left out.
- `./intern/cycles` & `./intern/atomic` are also excluded because they
use different header conventions.
doc/license/SPDX-license-identifiers.txt has been added to list SPDX all
used identifiers.
See P2788 for the script that automated these edits.
Reviewed By: brecht, mont29, sergey
Ref D14069
The case where Y rotation is mapped to Y rotation was not handled.
This is now fixed.
Also added an automated test to make sure that the symmetrize operator
functions as intended.
Reviewed By: Sybren
Differential Revision: http://developer.blender.org/D9214
This is from patch D13988. It removes the "- New" from the menu of the
new obj exporter, changes the default addon to just io_import_obj,
and does the right versioning thing.
Also disables the python tests for the old python exporter.
This is from patch D13988. It removes the "- New" from the menu of the
new obj exporter, changes the default addon to just io_import_obj,
and does the right versioning thing.
Also disables the python tests for the old python exporter.
Remove small ray offsets that were used to avoid self intersection, and leave
that to the newly added primitive object/prim comparison. These changes together
significantly reduce artifacts on small, large or far away objects.
The balance here is that overlapping primitives are not handled well and should
be avoided (though this was already an issue). The upside is that this is
something a user has control over, whereas the other artifacts had no good
manual solution in many cases.
There is a known issue where the Blender particle system generates overlapping
objects and in turn leads to render differences between CPU and GPU. This will
be addressed separately.
Differential Revision: https://developer.blender.org/D12954
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
I ran into this when adding new geometry nodes tests.
The issue was caused by 7168a4fa5c785c29483.
Differential Revision: https://developer.blender.org/D13440
The test script did not work on windows
since it had some trouble importing the
api module on the blender side of things.
turning the file path to the module into
a raw string literal sidesteps the
backslash issue in the path.
Differential Revision: https://developer.blender.org/D13163
Reviewed by: brecht
WITH_OPENCOLORIO and WITH_COMPOSITOR are required to run the tests at all,
since they affect many tests.
WITH_OPENSUBDIV WITH_FREESTYLE, WITH_OPENVDB, WITH_OPENIMAGEDENOISE and
WITH_MOD_FLUID selectively disable some tests.
