Commit Graph

17 Commits

Author SHA1 Message Date
Brecht Van Lommel
df00463764 Cycles: add shadow path compaction for GPU rendering
Similar to main path compaction that happens before adding work tiles, this
compacts shadow paths before launching kernels that may add shadow paths.

Only do it when more than 50% of space is wasted.

It's not a clear win in all scenes, some are up to 1.5% slower. Likely caused
by different order of scheduling kernels having an unpredictable performance
impact. Still feels like compaction is just the right thing to avoid cases
where a few shadow paths can hold up a lot of main paths.

Differential Revision: https://developer.blender.org/D12944
2021-10-21 15:38:03 +02:00
Brecht Van Lommel
0c52eed863 Cycles: more accurately count main paths for adding work tiles
Easy now thanks to the main and shadow path decoupling. Doesn't help
in an benchmark scene except Spring, where it reduces render time by
maybe 2-3%.

Ref T87836
2021-10-20 17:50:31 +02:00
Brecht Van Lommel
52c5300214 Cleanup: some renaming to better distinguish main and shadow paths 2021-10-20 17:50:31 +02:00
Brecht Van Lommel
cccfa597ba Cycles: make ambient occlusion pass take into account transparency again
Taking advantage of the new decoupled main and shadow paths. For CPU we
just store two nested structs in the integrator state, one for direct light
shadows and one for AO. For the GPU we restrict the number of shade surface
states to be executed based on available space in the shadow paths queue.

This also helps improve performance in benchmark scenes with an AO pass,
since it is no longer needed to use the shader raytracing kernel there,
which has worse performance.

Differential Revision: https://developer.blender.org/D12900
2021-10-20 17:50:31 +02:00
Brecht Van Lommel
943e73b07e Cycles: decouple shadow paths from main path on GPU
The motivation for this is twofold. It improves performance (5-10% on most
benchmark scenes), and will help  to bring back transparency support for the
ambient occlusion pass.

* Duplicate some members from the main path state in the shadow path state.
* Add shadow paths incrementally to the array similar to what we do for
  the shadow catchers.
* For the scheduling, allow running shade surface and shade volume kernels
  as long as there is enough space in the shadow paths array. If not, execute
  shadow kernels until it is empty.

* Add IntegratorShadowState and ConstIntegratorShadowState typedefs that
  can be different between CPU and GPU. For GPU both main and shadow paths
  juse have an integer for SoA access. Bt with CPU it's a different pointer
  type so we get type safety checks in code shared between CPU and GPU.
* For CPU, add a separate IntegratorShadowStateCPU struct embedded in
  IntegratorShadowState.
* Update various functions to take the shadow state, and make SVM take either
  type of state using templates.

Differential Revision: https://developer.blender.org/D12889
2021-10-19 15:09:29 +02:00
Campbell Barton
c5a13ffcb4 Cleanup: spelling in comments 2021-10-18 12:13:10 +11:00
Sergey Sharybin
aa46459543 Fix shadow catcher behind transparent object on GPU
The assumption about absent shadow path was wrong.

The rest of the changes are to ensure shadow paths are finished prior
to the split, so that they write to the proper passes.

The issue was caught by running regression tests on OptiX.

Differential Revision: https://developer.blender.org/D12857
2021-10-14 09:39:38 +02:00
Sergey Sharybin
cc04399937 Fix missing Cycles volume stack re-allocation
Need to check allocation size, as the features do not change with
volume stack depth detection.
2021-10-12 11:55:23 +02:00
Sergey Sharybin
719c319055 Fix Cycles long start on scene without volumes
The state template iteration had difficult time dealing with 0-sized
arrays, causing iteration for until integer overflows.
2021-10-07 15:54:56 +02:00
Sergey Sharybin
c6275da852 Fix T91922: Cycles artifacts with high volume nested level
Make volume stack allocated conditionally, potentially based on the
actual nested level of objects in the scene.

Currently the nested level is estimated by number of volume objects.
This is a non-expensive check which is probably enough in practice
to get almost perfect memory usage and performance.

The conditional allocation is a bit tricky.

For the CPU we declare and define maximum possible volume stack,
because there are only that many integrator states on the CPU.

On the GPU we declare outer SoA to have all volume stack elements,
but only allocate actually needed ones. The actually used volume
stack size is passed as a pre-processor, which seems to be easiest
and fastest for the GPU state copy.

There seems to be no speed regression in the demo files on RTX6000.

Note that scenes with high nested level of volume will now be slower
but correct.

Differential Revision: https://developer.blender.org/D12759
2021-10-06 15:46:32 +02:00
Sergey Sharybin
6e268a749f Fix adaptive sampling artifacts on tile boundaries
Implement an overscan support for tiles, so that adaptive sampling can
rely on the pixels neighbourhood.

Differential Revision: https://developer.blender.org/D12599
2021-10-05 16:19:14 +02:00
Sergey Sharybin
9a0850c8c2 Cycles: Fix wrong GPU state calculation
Currently was only used for logging, but better to fix the size so
that it matches reality.

The issue was caused by decoupling number of shadow intersections
and using much higher number for CPU. This caused the total state
on GPU to be logged as 10s of gigabytes instead of 100s of megabytes.

Differential Revision: https://developer.blender.org/D12755
2021-10-05 16:09:31 +02:00
Brecht Van Lommel
a754e35198 Cycles: refactor API for GPU display
* Split GPUDisplay into two classes. PathTraceDisplay to implement the Cycles side,
  and DisplayDriver to implement the host application side. The DisplayDriver is now
  a fully abstract base class, embedded in the PathTraceDisplay.
* Move copy_pixels_to_texture implementation out of the host side into the Cycles side,
  since it can be implemented in terms of the texture buffer mapping.
* Move definition of DeviceGraphicsInteropDestination into display driver header, so
  that we do not need to expose private device headers in the public API.
* Add more detailed comments about how the DisplayDriver should be implemented.

The "driver" terminology might not be obvious, but is also used in other renderers.

Differential Revision: https://developer.blender.org/D12626
2021-09-30 20:48:08 +02:00
Brecht Van Lommel
4d4113adc2 Cycles: record large number of transparent shadow intersections on CPU
So we can do fewer intersection calls, only on the GPU do we need to save
memory and do this in small steps.

Ref T87836
2021-09-29 16:37:32 +02:00
Sergey Sharybin
731325a022 Cycles: Make sure GPU transfer is finished prior display update
Noticed while looking into flickering issues in viewport.

Doesn't seem to solve the flicker issue for me, but is something
what is supposed to be happening anyway.

Differential Revision: https://developer.blender.org/D12673
2021-09-29 14:05:51 +02:00
Campbell Barton
4d66cbd140 Cleanup: spelling in comments 2021-09-22 14:54:01 +10:00
Brecht Van Lommel
0803119725 Cycles: merge of cycles-x branch, a major update to the renderer
This includes much improved GPU rendering performance, viewport interactivity,
new shadow catcher, revamped sampling settings, subsurface scattering anisotropy,
new GPU volume sampling, improved PMJ sampling pattern, and more.

Some features have also been removed or changed, breaking backwards compatibility.
Including the removal of the OpenCL backend, for which alternatives are under
development.

Release notes and code docs:
https://wiki.blender.org/wiki/Reference/Release_Notes/3.0/Cycles
https://wiki.blender.org/wiki/Source/Render/Cycles

Credits:
* Sergey Sharybin
* Brecht Van Lommel
* Patrick Mours (OptiX backend)
* Christophe Hery (subsurface scattering anisotropy)
* William Leeson (PMJ sampling pattern)
* Alaska (various fixes and tweaks)
* Thomas Dinges (various fixes)

For the full commit history, see the cycles-x branch. This squashes together
all the changes since intermediate changes would often fail building or tests.

Ref T87839, T87837, T87836
Fixes T90734, T89353, T80267, T80267, T77185, T69800
2021-09-21 14:55:54 +02:00