In forward path tracing, when we pass volume bounding meshes, we
accumulate `volume_bounds_bounce`. We should match this behaviour in NEE
instead of accumulating `transparent_bounce`.
Pull Request: https://projects.blender.org/blender/blender/pulls/137556
Reduce the register pressure and branching in the switch() by using
subclass and cast from void* to the base class.
This ensures intersection functions are not inlined multiple times,
bringing performance back.
Alternative could be to avoid functions (they are quite large) but
that only partially resolves the performance regression.
Pull Request: https://projects.blender.org/blender/blender/pulls/136823
HIP-RT functions do have access to kg, and it was used inconsistently:
some functions were passed actual kg, other were passed nullptr.
This change makes it consistent and passes kg everywhere.
Pull Request: https://projects.blender.org/blender/blender/pulls/136503
The code before this change was relying on the ShadowPayload have
the same "header" as RayPayload for some of the primitive types
(curve, motion triangle, point): intersection functions were shared
between "regular" and shadow rays (shadow in this case is shadow_all),
but extra filter function was used for shadow rays.
This is fragile if someone changes one of these structures. What is
worse is that compiler might actually decide to shuffle things in
some structs, or remove unused fields.
This change also solves confusion about ShadowPayload::prim_type
seemingly only being assigned to PRIMITIVE_NONE. With time it is
not impossible that compiler will also see this, and constant-fold
some checks, or even remove the field. If that happens then the
render result will be wrong. Maybe it is already happening as there
are some GPU and driver and optimization flag specific bugs in the
area.
It is unclear whether it was causing any actual problem: W7800
seems to render all hair correctly on Linux.
Also make some style decisions more consistent: for example,
the way how stop/continue search return value is commented.
Prefer lower vertical space for those.
Mainly readability purposes:
- Having variables called local_payload is ambiguous: does it refer to
LocalPayload type or to a variable be local in a function?
- Some of the functions are used for different ray types, so having the
type case in intersectFunc and filterFunc makes it easier to scan.
For the latter: now it is more obvious that Curve_Intersect_Shadow
expects RayPayload, but Curve_Filter_Shadow expects ShadowPayload.
It might not be a problem currently as ShadowPayload has the same
"header" RayPayload, but it might change in the future. Also, compiler
might optimize fields out from one but not from the other.
The reason for this to happen is because when spatial split is used
the same intersection could be recorded twice (via different BVH nodes).
This change introduces check for the intersection being already recoded,
similar to the check in the local BVH. The check is done during BVH
intersection which allows to properly ignore intersections even for the
maximum bounce number check. A faster approach would be to do such
filtering after sorting, but then we can not keep bounce check in the
BVH code consistent with and without spatial splits.
Intuitively it seems that it should be possible to merge the new loop
with the one that checks for which intersection to keep. But it is not
so trivial in practice: it doesn't run for all intersections, and also
it is formulated in a way that updates isect_index for the next record.
Pull Request: https://projects.blender.org/blender/blender/pulls/136251
The code which was checking whether local intersection is to be
recorded, and under which index was duplicated for triangles,
motion triangles, and HIP-RT triangle filter function.
This change moves the common logic to an utility function which
is reused from all the places mentioned above.
Pull Request: https://projects.blender.org/blender/blender/pulls/136244
This change fixes the remaining failing tests with SSS when using HIP-RT.
This includes crash when SSS is used on curves, and objects with motion
blur and SSS rendering black.
The root cause for both cases was the fact that traversal was always
assuming regular BVH (built for triangles), while curves and motion
triangles are using custom primitives, which requires specialized BVH
traversal.
This change includes:
- Early output from `scene_intersect_local()` for non-triangle and
non-motion-triangle primitives. This fixes `sss_hair.blend` test,
and also avoids unnecessary BVH traversal when the local intersection
is requested from curve object. The same early-output could be added
to other BVH traversal implementation.
- Use `hiprtGeomCustomTraversalAnyHitCustomStack` for motion triangles
primitives. This fixes motion blur on objects with SSS render black.
Fixes#135856
Co-authored-by: Sahar A. Kashi <sahar.alipourkashi@amd.com>
Co-authored-by: Sergey Sharybin <sergey@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/135943
It was always hard-coded to be 0.
It does not seem to result in any extra tests passing, but they are
probably not sophisticated enough.
Noticed while looking into details for the #135856.
Pull Request: https://projects.blender.org/blender/blender/pulls/135878
Previously point cloud rendering was disabled on the HIPRT backend due
to unexpected performance regressions introduce by it.
With the recent update to HIP SDK 6.3 and HIPRT 2.5, these performance
regressions have been resolved and so this commit re-enables
point cloud rendering on HIPRT.
Pull Request: https://projects.blender.org/blender/blender/pulls/134902
This change brings the following improvements on the user level
- Support of GPUs with gfx12 architecture
- New HIP-RT library which in addition to the gfx12 support brings
various bug-fixes.
The known limitation of gfx12 is that OpenImageDenoiser does not yet
support this GPU architecture. This means that while Cycles will use the
full advantage of the gfx12 (including hardware accelerated ray-tracing),
denoising will only be possible on CPU, or secondary gfx11 or below GPU.
This is something that requires a change in OIDN and it is to late to do
it for Blender 4.4, but it is something to look forward for Blender 4.5.
The gfx12 changes for the pre-compiled kernels is rather trivial,
so it comes together (in the same PR) as the bigger HIP-RT change.
On the development side this change brings the following improvements:
- One step compile and link (much simpler CMake rules)
- Embedding BVH binaries in hiprt dll (which makes it easier to package
and load, without relying on special path configuration)
Co-authored-by: Sahar Kashi <sahar.kashi@amd.com>
Co-authored-by: Sergey Sharybin <sergey@blender.org>
Co-authored-by: Brecht Van Lommel <brecht@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/133129
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
This change switches Cycles to an opensource HIP-RT library which
implements hardware ray-tracing. This library is now used on
both Windows and Linux. While there should be no noticeable changes
on Windows, on Linux this adds support for hardware ray-tracing on
AMD GPUs.
The majority of the change is typical platform code to add new
library to the dependency builder, and a change in the way how
ahead-of-time (AoT) kernels are compiled. There are changes in
Cycles itself, but they are rather straightforward: some APIs
changed in the opensource version of the library.
There are a couple of extra files which are needed for this to
work: hiprt02003_6.1_amd.hipfb and oro_compiled_kernels.hipfb.
There are some assumptions in the HIP-RT library about how they
are available. Currently they follow the same rule as AoT
kernels for oneAPI:
- On Windows they are next to blender.exe
- On Linux they are in the lib/ folder
Performance comparison on Ubuntu 22.04.5:
```
GPU: AMD Radeon PRO W7800
Driver: amdgpu-install_6.1.60103-1_all.deb
main hip-rt
attic 0.1414s 0.0932s
barbershop_interior 0.1563s 0.1258s
bistro 0.2134s 0.1597s
bmw27 0.0119s 0.0099s
classroom 0.1006s 0.0803s
fishy_cat 0.0248s 0.0178s
junkshop 0.0916s 0.0713s
koro 0.0589s 0.0720s
monster 0.0435s 0.0385s
pabellon 0.0543s 0.0391s
sponza 0.0223s 0.0180s
spring 0.1026s 1.5145s
victor 0.1901s 0.1239s
wdas_cloud 0.1153s 0.1125s
```
Co-authored-by: Brecht Van Lommel <brecht@blender.org>
Co-authored-by: Ray Molenkamp <github@lazydodo.com>
Co-authored-by: Sergey Sharybin <sergey@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/121050
Temporarily disable point cloud rendering in HIPRT to fix a performance
regression triggered by increased register preasure until
a better solution can be developed.
Pull Request: https://projects.blender.org/blender/blender/pulls/127738
The device code was disabled for primitives with deformation blur
and the intersection function always returned false, hence no
rendered primitive.
Other than that, there were a few bugs on both device and host codes
(e.g., the order of current and previous times and the primitive name.)
Pull Request: https://projects.blender.org/blender/blender/pulls/127163
Fixes a few issues with point clouds with HIPRT.
1. Crashing when building the BLAS due to an incorrect sized array.
2. A typo leading to all point cloud intersections being skipped.
3. A typo leading to some motion blurred point clouds rendering
as if they were stationary, or not rendering at all.
Pointclouds, with deformable motion blur, with BVH time steps set to >0
still do not render. Curves seem to have the same issue.
Ref #125086
Pull Request: https://projects.blender.org/blender/blender/pulls/125834
This PR contains optimisations and a general tidy-up of the MetalRT backend.
- Currently `scene_intersect` is used for both normal and (opaque) shadow rays, however the usage patterns are different enough to warrant specialisation. Shadow intersection tests (flagged with `PATH_RAY_SHADOW_OPAQUE`) only need a bool result, but need a larger "self" payload in order to exclude hits against target lights. By specialising we can minimise the payload size in each case (which is helps performance) and avoid some dynamic branching. This PR introduces a new `scene_intersect_shadow` function which is specialised in Metal, and currently redirects to `scene_intersect` in the other backends.
- Currently `scene_intersect_local` is implemented for worst-case payload requirements as demanded by `subsurface_disk` (where `max_hits` is 4). The random_walk case only demands 1 hit result which we can retrieve directly from the intersector object (rather than stashing it in the payload). By specialising, we significantly reduce the payload size for random_walk queries, which has a big impact on performance. Additionally, we only need to use a custom intersection function for the first ray test in a random walk (for self-primitive filtering), so this PR forces faster `opaque` intersection testing for all but the first random walk test.
- Currently `scene_intersect_volume` has a lot of redundant code to handle non-triangle primitives despite volumes only being enclosed by trimeshes. This PR removes this code.
Additionally, this PR tidies up the convoluted intersection function linking code, removes some redundant intersection handlers, and uses more consistent naming of intersection functions.
On a M3 MacBook Pro, these changes give 2-3% performance increase on typical scenes with opaque trimesh materials (e.g. barbershop, classroom junkshop), but can give over 15% performance increase for certain scenes using random walk SSS (e.g. monster).
Pull Request: https://projects.blender.org/blender/blender/pulls/121397
The first problem was triangles with motion blur were all grouped into
one category without separating the ones with and without triangle
motion steps.
The second problem was HIP RT uses the generic motion triangle
intersection function and this function checks prim_visibility buffer.
HIP RT doesn't provide the buffer per primitive but passes it to HIP RT
core per instance.
The buffer name was changed to prim_visibility from visibility to be
the same as what Cycles uses but when the motion triangle intersection
function is called from HIP RT kernels, the instance id is passed to
the function instead of primitive id.
Pull Request: https://projects.blender.org/blender/blender/pulls/114555
HIP RT enables AMD hardware ray tracing on RDNA2 and above, and falls back to a
to shader implementation for older graphics cards. It offers an average 25%
sample rendering rate improvement in Cycles benchmarks, on a W6800 card.
The ray tracing feature functions are accessed through HIP RT SDK, available on
GPUOpen. HIP RT traversal functionality is pre-compiled in bitcode format and
shipped with the SDK.
This is not yet enabled as there are issues to be resolved, but landing the
code now makes testing and further changes easier.
Known limitations:
* Not working yet with current public AMD drivers.
* Visual artifact in motion blur.
* One of the buffers allocated for traversal has a static size. Allocating it
dynamically would reduce memory usage.
* This is for Windows only currently, no Linux support.
Co-authored-by: Brecht Van Lommel <brecht@blender.org>
Ref #105538
