Offset rays from the flat surface to match where they would be for a smooth
surface as specified by the normals. In the shading panel there is now a
Shading Offset (existing option) and Geometry Offset (new).
The Geometry Offset works as follows:
* 0: disabled
* 0.001: only terminated triangles (normal points to the light, geometry
doesn't) are affected
* 0.1 (default): triangles at grazing angles are affected, and the effect
fades out
* 1: all triangles are affected
Limitations:
* The artifact is still visible in some cases, it could be that some quads
require to be treated specifically as quads.
* Inconsistent normals cause artifacts.
* If small objects cast shadows to a big low poly surface, the shadows can
appear to be in a wrong place - because the surface moved slightly above
the geometry. This can be noticed only at grazing angles to light.
* Approximated surfaces of two non-intersecting low-poly objects can overlap
that causes off-the-wall shadows.
Generally, using one or a few levels of subdivision can get rid of artifacts
faster than before.
Differential Revision: https://developer.blender.org/D11065
Adds support for building multiple BVH types in order to support using both CPU and OptiX
devices for rendering simultaneously. Primitive packing for Embree and OptiX is now
standalone, so it only needs to be run once and can be shared between the two. Additionally,
BVH building was made a device call, so that each device backend can decide how to
perform the building. The multi-device for instance creates a special multi-BVH that holds
references to several sub-BVHs, one for each sub-device.
Reviewed By: brecht, kevindietrich
Differential Revision: https://developer.blender.org/D9718
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
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
The kernel did not work correctly when these were disabled anyway. The
optimized BVH traversal for the no instances case was also only used on
the CPU, so no longer makes sense to keep.
Ref T73778
Depends on D8010
Maniphest Tasks: T73778
Differential Revision: https://developer.blender.org/D8011
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:
Embree's local intersection routine was not prepared
for local intersections without per-object BVH.
Now it should be able to handle any kind of local
intersection, such as AO, bevel and SSS.
Differential Revision: https://developer.blender.org/D6602
This never really worked as it was supposed to. The main goal of this is to
turn noise from sampling tiny hairs into multiple layers of transparency that
do not need to be sampled stochastically. However the implementation of this
worked by randomly discarding hair intersections in BVH traversal, which
defeats the purpose.
If it ever comes back, it's best implemented outside the kernel as a preprocess
that changes hair radius before BVH building. This would also make it work with
Embree, where it's not supported now. But it's not so clear anymore that with
many AA samples and GPU rendering this feature is as helpful as it once was for
CPU raytracers with few AA samples.
The benefit of removing this feature is improved hair ray tracing performance,
tested on NVIDIA Titan Xp:
bmw27: +0.37%
classroom: +0.26%
fishy_cat: -7.36%
koro: -12.98%
pabellon: -0.12%
Differential Revision: https://developer.blender.org/D4532
Was happening when looking for all intersections for transparent shadow rays
in the case the ray is degenerate.
Still quesitonable whether we should consider this a transparent or opaque
configuraiton. Ideally, we should prevent such rays from happening, but that
is another vector of debugging.
BF-admins agree to remove header information that isn't useful,
to reduce noise.
- BEGIN/END license blocks
Developers should add non license comments as separate comment blocks.
No need for separator text.
- Contributors
This is often invalid, outdated or misleading
especially when splitting files.
It's more useful to git-blame to find out who has developed the code.
See P901 for script to perform these edits.
This commit adds a sample-based profiler that runs during CPU rendering and collects statistics on time spent in different parts of the kernel (ray intersection, shader evaluation etc.) as well as time spent per material and object.
The results are currently not exposed in the user interface or per Python yet, to see the stats on the console pass the "--cycles-print-stats" argument to Cycles (e.g. "./blender -- --cycles-print-stats").
Unfortunately, there is no clear way to extend this functionality to CUDA or OpenCL, so it is CPU-only for now.
Reviewers: brecht, sergey, swerner
Reviewed By: brecht, swerner
Differential Revision: https://developer.blender.org/D3892
While we shouldn't have logic in an entry point, and since one should
not be making typos when moving lines around, there is bigger entanglement
issue with BVH host code using kernel function. This is bad violation,
but is tricky to get solved moments before the weekly.
In order to keep things in a (less) broken state than before own cleanup
reverting the changes.
This reverts commit 2bad10be96.
This reverts commit ddabb21d05
Note that this is turned off by default and must be enabled at build time with the CMake WITH_CYCLES_EMBREE flag.
Embree must be built as a static library with ray masking turned on, the `make deps` scripts have been updated accordingly.
There, Embree is off by default too and must be enabled with the WITH_EMBREE flag.
Using Embree allows for much faster rendering of deformation motion blur while reducing the memory footprint.
TODO: GPU implementation, deduplication of data, leveraging more of Embrees features (e.g. tessellation cache).
Differential Revision: https://developer.blender.org/D3682
The crash was caused by BVH traversal stack being overflowed.
That overflow was caused by lots of false-positive intersections
for rays originating on a non-finite location.
Not sure why those rays will be existing in the first place,
this is to be investigated separately.
This commit moves pre-SSE4.1 check to a higher level function
and enables it for all miroarchitectures.
This is an initial implementation of BVH8 optimization structure
and packated triangle intersection. The aim is to get faster ray
to scene intersection checks.
Scene BVH4 BVH8
barbershop_interior 10:24.94 10:10.74
bmw27 02:41.25 02:38.83
classroom 08:16.49 07:56.15
fishy_cat 04:24.56 04:17.29
koro 06:03.06 06:01.45
pavillon_barcelona 09:21.26 09:02.98
victor 23:39.65 22:53.71
As memory goes, peak usage raises by about 4.7% in a complex
scenes.
Note that BVH8 is disabled when using OSL, this is because OSL
kernel does not get per-microarchitecture optimizations and
hence always considers BVH3 is used.
Original BVH8 patch from Anton Gavrikov.
Batched triangles intersection from Victoria Zhislina.
Extra work and tests and fixes from Maxym Dmytrychenko.
This means the shader can now be used for procedural texturing. New
settings on the node are Samples, Inside, Local Only and Distance.
Original patch by Lukas with further changes by Brecht.
Differential Revision: https://developer.blender.org/D3479
Not sure why exactly it is called a cleanup, the code was much more clear
and robust against possible missing return statements which are MANDATORY.
Missing return statement will:
- Cause two different BVH traversals to be run.
Not is happening currently, but if more BVH layouts are added, it will
become a problem.
- It is already causing assert() statements to fail, since functions are
no longer returning when they are supposed to.
If there is any measurable reason to keep this change, let me know.
Otherwise just stick to reliable/tested/robust code.
This reverts commit ba65f7093b.
