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 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
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:
OSLRenderServices contains a member which is 64 bytes aligned and this
is onlys supported by default allocators in SDK 10.14. Since we take
care of allocation ourselves ignoring the diagnostic is an acceptable
way dealign with it.
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
This code is currently only used for the Glossy Toon BSDF, but it's a generic
building block that might be used for other things in the future.
To see why the current code does not give a uniform distribution, consider that
it chooses both angles uniformly, but the smaller the angle from the center of
the cone is, the smaller the differential solid angle is (similar to how
sampling disks by choosing radius and phi uniformly does not work).
Differential Revision: https://developer.blender.org/D7948
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 input data to the OptiX denoiser was clamped to 0..10000 as required, but it could easily
exceed that range with a high number of samples (since the data contains the overall sum). To
fix that, divide by the number of samples first and multiply it back in after the denoiser ran.
There should be no user visible change from this, except that tile size
now affects performance. The goal here is to simplify bake denoising in
D3099, letting it reuse more denoising tiles and pass code.
A lot of code is now shared with regular rendering, with the two main
differences being that we read some render result passes from the bake API
when starting to render a tile, and call the bake kernel instead of the
path trace kernel.
With this kind of design where Cycles asks for tiles from the bake API,
it should eventually be easier to reduce memory usage, show tiles as
they are baked, or bake multiple passes at once, though there's still
quite some work needed for that.
Reviewers: #cycles
Subscribers: monio, wmatyjewicz, lukasstockner97, michaelknubben
Differential Revision: https://developer.blender.org/D3108
Since the sampling and evaluation functions handle both cases anyways,
there's not really a point for keeping the distinction in the kernel,
so we might as well cut down the number of CLOSURE_BSDF_MICROFACETs a bit.
Differential Revision: https://developer.blender.org/D7736
Recent changes assumed OpenCL 2.0 platform. This adds a check to see if
we are compiling on an OpenCL 2.0 platform.
Patch was tested on:
* AMD Radeon Pro WX 7100 with amdgpu-pro-19.50-1011208-ubuntu-18.04 drivers
* AMD Vega 64 with amdgpu-pro-20.10-1048554-ubuntu-18.04 drivers
* AMD RX 5700 with amdgpu-pro-20.10-1048554-ubuntu-18.04 drivers
Reviewed By: Brecht van Lommel
Differential Revision: https://developer.blender.org/D7637
This patch will add some compiler hints to break unrolling in the
nestled for loops of the voronoi node.
Reviewed by: Brecht van Lommel
Differential Revision: https://developer.blender.org/D7574
CMake: `WITH_CYCLES_DEVICE_OPTIX` did not respect `WITH_CYCLES_CUDA_BINARIES` causing the optix kernel to be always build at build time.
Code: `device_optix.cpp` did not count on the optix kernel not existing in the default location.
For this to work, one should have before starting blender
1) working nvcc environment
2) Optix SDK installed and the OPTIX_ROOT_DIR environment variable pointing to it which is not set by default
Differential Revision: https://developer.blender.org/D7400
Reviewed By: Brecht
Currently in fractal_noise functions, each subsequent octave doubles the
frequency and reduces the amplitude by half. This patch introduces Roughness
input to Noise and Wave nodes. This multiplier determines how quickly the
amplitudes of the subsequent octaves decrease.
Value of 0.5 will be the default, generating identical noise we had before.
Values above 0.5 will increase influence of each octave resulting in more
"rough" noise, most interesting pattern changes happen there. Values below
0.5 will result in more "smooth" noise.
Differential Revision: https://developer.blender.org/D7065
This patch adds an AVX implementation of Perlin noise in Cycles.
An avxi type was also added as a utility based on the respective
type in Intel Embree.
Only 3D and 4D noise were implemented, there is no benefit for
utilizing AVX in 1D and 2D noise. The SSE trilinear interpolation
function was used in the AVX implementation because there is no
benefit from using AVX in interpolating the last three dimensions.
Differential Revision: https://developer.blender.org/D6680
Random Walk subsurface scattering did look different with OptiX because transmittance is
calculated based on the hit distance, but the OptiX implementation of `scene_intersect_local`
would return the distance in world space, while the Cycles BVH version returns it in object
space. This fixes the problem by simply skipping the object->world transforms in all the
places using the result of `scene_intersect_local` with OptiX.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D7232
We appear to be hitting some limit where adding any amount of code causes a
significant performance regression, no matter what it does. To work around
that a new node level was added.
Ref T71479
