Also minor changes in comments:
- Reference BLENDER_HISTORY_FILE instead of the literal file-name
(simplifies looking up usage).
- Use usernames in tags, as noted in code-style.
Based on "Sampling the GGX Distribution of Visible Normals" by Eric Heitz
(https://jcgt.org/published/0007/04/01/).
Also, this removes the lambdaI computation from the Beckmann sampling code and
just recomputes it below. We already need to recompute for two other cases
(GGX and clearcoat), so this makes the code more consistent.
In terms of performance, I don't expect a notable impact since the earlier
computation also was non-trivial, and while it probably was slightly more
accurate, I'd argue that being consistent between evaluation and sampling is
more important than absolute numerical accuracy anyways.
Differential Revision: https://developer.blender.org/D17100
This gives closer results to what I've seen in papers and other renderers when
using the code to precompute albedo later (to replace MultiGGX).
It's usually a tiny difference, the only case where I've seen it matter is
in the `shader/node_group_float.blend` test - but that's a (single-scatter) GGX
closure with 0.9 roughness, so it's not too surprising. In any case, the new
result looks closer to Eevee, so that's good I guess.
Differential Revision: https://developer.blender.org/D17099
Speckles and missing lights were experienced in scenes with Nishita Sky
Texture and a Sun Size smaller than 1.5°, such as in Lone Monk and Attic
scenes.
Increasing the precision of cosf fixes it.
The background evaluation samples the sky discretely, so if the sun is
too small, it can be missed in the evaluation. To solve this, the sun is
ignored during the background evaluation and its contribution is
computed separately.
The lookup table method on CPU and the numerical root finding method on
GPU give quite different results. This commit deletes the Beckmann lookup
table and uses numerical root finding on all devices. For the numerical
root finding, a combined bisection-Newton method with precision control
is used.
Differential Revision: https://developer.blender.org/D17050
This makes it possible to use `texture` and `texture3d` in custom
OSL shaders with a constant image file name as argument on the
GPU, where previously texturing was only possible through Cycles
nodes.
For constant file name arguments, OSL calls
`OSL::RendererServices::get_texture_handle()` with the file name
string to convert it into an opaque handle for use on the GPU.
That is now used to load the respective image file using the Cycles
image manager and generate a SVM handle that can be used on
the GPU. Some care is necessary as the renderer services class is
shared across multiple Cycles instances, whereas the Cycles image
manager is local to each.
Maniphest Tasks: T101222
Differential Revision: https://developer.blender.org/D17032
This patch adds markup to specify that certain kernel data constants should not be specialised. Currently it is used for `tabulated_sobol_sequence_size` and `sobol_index_mask` which change frequently based on the aa sample count, trash the shader cache, and have little bearing on performance.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D16968
wi is the viewing direction, and wo is the illumination direction. Under this notation, BSDF sampling always samples from wi and outputs wo, which is consistent with most of the papers and mitsuba. This order is reversed compared with PBRT, although PBRT also traces from the camera.
While keeping SSE2, SSE4.1 and AVX2. This does not affect hardware support, it
only slightly reduces performance for some older CPUs.
To reduce maintenance cost and improve compile times.
Differential Revision: https://developer.blender.org/D16978
When rendering in the viewport (or probably on instanced objects, but I didn't
test that), emissive objects whose scale is negative give the wrong value on the
"backfacing" input when multiple sampling is enabled.
The underlying problem was a corner case in how normal transformation is handled,
which is generally a bit messy.
From what I can tell, the pattern appears to be:
- If you first transform vertices to world space and then compute the normal from
them (as triangle light samping, MNEE and light tree do), you need to flip
whenever the transform has negative scale regardless of whether the transform
has been applied
- If you compute the normal in object space and then transform it to world space
(as the regular shader_setup_from_ray path does), you only need to flip if the
transform was already applied and was negative
- If you get the normal from a local intersection result (as bevel and SSS do),
you only need to flip if the transform was already applied and was negative
- If you get the normal from vertex normals, you don't need to do anything since
the host-side code does the flip for you (arguably it'd be more consistent to
do this in the kernel as well, but meh, not worth the potential slowdown)
So, this patch fixes the logic in the triangle emission code.
Also, turns out that the MNEE code had the same problem and was also having
problems in the viewport on negative-scale objects, this is also fixed now.
Differential Revision: https://developer.blender.org/D16952
At the first bounce, the diffuse/glossy/transmission weights are stored so that
contributions along the path can be split into the d/g/t indirect passes.
However, volume bounces always set the weight even at indirect bounces, so
even paths that had their first bounce on a purely glossy object would suddenly
start counting towards the diffuse indirect pass after a secondary volume bounce.
This breaks backwards compatibility some in that 3 sides will be mapped
differently now, but difficult to avoid and can be considered a bugfix.
Similar to rBdd8016f7081f.
Maniphest Tasks: T103615
Differential Revision: https://developer.blender.org/D16910
This functionality is related only to debugging of SYCL implementation
via single-threaded CPU execution and is disabled by default.
Host device has been deprecated in SYCL 2020 spec and we removed it
in 305b92e05f.
Since this is still very useful for debugging, we're restoring a
similar functionality here through SYCL 2020 Host Task.
The "osl_texture" intrinsic was not implemented correctly. It should handle alpha
separately from color, the number of channels input parameter only counts color
channels.
Partially addresses T72011.
The problem here is that the previous barycentric clamping did not deal well
with skinny triangles and would end up generating "sub-pixel jittering"
locations that were actually >20 pixels away.
Differential Revision: https://developer.blender.org/D16727
Expands Color Mix nodes with new Exclusion mode.
Similar to Difference but produces less contrast.
Requested by Pierre Schiller @3D_director and
@OmarSquircleArt on twitter.
Differential Revision: https://developer.blender.org/D16543
Replace ../lib/linux_centos7_x86_64 with ../lib/linux_x86_64_glibc_228,
built with Rocky8 Linux, compatible with the VFX platform CY2023,
see: T99618.
- Update build-bot configuration.
- Remove unnecessary check for Blosc, this is part of OpenVDB lib now.
- Remove WITH_CXX11_ABI, always use new C++11 ABI now
- Replace centos7 by glibc_228 everywhere
Note that existing builds with cached paths pointing to
"../lib/linux_centos7_x86_64" will need to be updated.
Includes contributions by Brecht.
This adds a new mirror image extension type for shaders and
geometry nodes (next to the existing repeat, extend and clip
options).
See D16432 for a more detailed explanation of `wrap_mirror`.
This also adds a new sampler flag `GPU_SAMPLER_MIRROR_REPEAT`.
It acts as a modifier to `GPU_SAMPLER_REPEAT`, so any `REPEAT`
flag must be set for the `MIRROR` flag to have an effect.
Differential Revision: https://developer.blender.org/D16432
This is done based on the render sample count so that it doesn't impact
sampling quality. It's similar in spirit to the adaptive table size in D16561,
but in this case for performance rather than memory usage.
Differential Revision: https://developer.blender.org/D16726
The first two dimensions of scrambled, shuffled Sobol and shuffled PMJ02 are
equivalent, so this makes no real difference for the first two dimensions.
But Sobol allows us to naturally extend to more dimensions.
Pretabulated Sobol is now always used, and the sampling pattern settings is now
only available as a debug option.
This in turn allows the following two things (also implemented):
* Use proper 3D samples for combined lens + motion blur sampling. This
notably reduces the noise on objects that are simultaneously out-of-focus
and motion blurred.
* Use proper 3D samples for combined light selection + light sampling.
Cycles was already doing something clever here with 2D samples, but using
3D samples is more straightforward and avoids overloading one of the
dimensions.
In the future this will also allow for proper sampling of e.g. volumetric
light sources and other things that may need three or four dimensions.
Differential Revision: https://developer.blender.org/D16443
The use of a struct for device strings caused the CUDA compiler to
generate byte arrays as the argument type, whereas OSL generated
primitive integer types (for the hash). Fix that by using a typedef
instead so that the CUDA compiler too will use an integer type in the
PTX it generates.
Maniphest Tasks: T101222
There has been an attempt to reorganize this part, however, it seems that didn't compile on HIP, and is reverted in
rBc2dc65dfa4ae60fa5d2c3b0cfe86f99dcb5bf16f. This is another attempt of refactoring. as I have no idea why some things don't work on HIP, it's
best to check whether this compiles on other platforms.
The main changes are creating a new struct named `MeshLight` that is shared between `KernelLightDistribution` and `KernelLightTreeEmitter`,
and a bit of renaming, so that light sampling with or without light tree could call the same function.
Also, I noticed a patch D16714 referring to HIP compilation error. Not sure if it's related, but browsing
https://builder.blender.org/admin/#/builders/30/builds/7826/steps/7/logs/stdio, it didn't work on gfx1102, not gfx9*.
Differential Revision: https://developer.blender.org/D16722
