Commit Graph

38 Commits

Author SHA1 Message Date
Alaska
9b3699db67 Fix: Cycles invalid normals in various situations
Fix issues related to NaN normals in some situations by trying
to detect when these cases might occur and just reverting back
to default normals.

As a side effect of these changes, OSL now behaves correctly
when given a non-normalized normal.

Pull Request: https://projects.blender.org/blender/blender/pulls/114960
2024-01-02 16:24:04 +01:00
Brecht Van Lommel
8845dba79d Fix Cycles rare assert in ensure_valid_specular_reflection
When the incoming direction is exactly orthogonal to the normal

Ref #115071
2023-11-21 18:39:56 +01:00
Lukas Stockner
173ba71b6b Merge branch 'blender-v4.0-release' 2023-10-19 13:26:22 +02:00
Lukas Stockner
c71e18054c Fix: Cycles: Non-physical layering weights can lead to negative closures 2023-10-19 13:13:48 +02:00
Sergey Sharybin
36e603c430 Cycles: Add option to control smoothing when using bump map
Cycles implements the "Taming the Shadow Terminator" paper by Matt Jen-Yuan
Chiang to solve shadow terminator issues when a bump map is applied, as well
as similar approach for the glossy reflection to ensure ray does not get
reflected to inside of the object.

This correction term is applied unconditionally, which makes it harder to have
full control over shading via normals for stylistic reasons.

This change exposes this corrective term as an option called "Bump Map
Correction" which is available in the shader settings next to the
"Transparent Shadows".

The reason to make it per-shader rather than per-object is to allow flexibility
of a control: it is possible that an object has multiple shaders attached to it,
and only some of them used for bump mapping. Another, and possibly stronger
reason to have it per-shader is ease of assets control: shader brings settings
which are needed for its proper behavior. So if material at some point
decides to take over normals, artists would not need to update settings on
every asset which uses that material.

The option is enabled by default, so there is no changes for existing setups.

Pull Request: https://projects.blender.org/blender/blender/pulls/113480
2023-10-11 15:07:21 +02:00
Weizhen Huang
f96b9db610 Cleanup: remove redundant fresnel_dielectric()
We already have two other functions doing very much the same thing.
`bsdf_microfacet_sample()` seems to be the only place where this
function was used; there we always sample visible normals, so the extra
`inside` check is not needed.
2023-09-08 16:53:12 +02:00
Weizhen Huang
6f8011edf7 Cycles: new Principled Hair BSDF variant with elliptical cross-section support
Implements the paper [A Microfacet-based Hair Scattering
Model](https://onlinelibrary.wiley.com/doi/full/10.1111/cgf.14588) by
Weizhen Huang, Matthias B. Hullin and Johannes Hanika.

### Features:
- This is a far-field model, as opposed to the previous near-field
Principled Hair BSDF model. The hair is expected to be less noisy, but
lower roughness values takes longer to render due to numerical
integration along the hair width. The hair also appears to be flat when
viewed up-close.
- The longitudinal width of the scattering lobe differs along the
azimuth, providing a higher contrast compared to the evenly spread
scattering in the near-field Principled Hair BSDF model. For a more
detailed comparison, please refer to the original paper.
- Supports elliptical cross-sections, adding more realism as human hairs
are usually elliptical. The orientation of the cross-section is aligned
with the curve normal, which can be adjusted using geometry nodes.
Default is minimal twist. During sampling, light rays that hit outside
the hair width will continue propogating as if the material is
transparent.
- There is non-physical modulation factors for the first three
lobes (Reflection, Transmission, Secondary Reflection).

### Missing:
- A good default for cross-section orientation. There was an
attempt (9039f76928) to default the orientation to align with the curve
normal in the mathematical sense, but the stability (when animated) is
unclear and it would be a hassle to generalise to all curve types. After
the model is in main, we could experiment with the geometry nodes team
to see what works the best as a default.

Co-authored-by: Lukas Stockner <lukas.stockner@freenet.de>
Pull Request: https://projects.blender.org/blender/blender/pulls/105600
2023-08-18 12:46:13 +02:00
Campbell Barton
c12994612b License headers: use SPDX-FileCopyrightText in intern/cycles 2023-06-14 16:53:23 +10:00
Lukas Stockner
888bdc1419 Cycles: Remove MultiGGX code, replace with albedo scaling
While the multiscattering GGX code is cool and solves the darkening problem at higher roughnesses, it's also currently buggy, hard to maintain and often impractical to use due to the higher noise and render time.

In practice, though, having the exact correct directional distribution is not that important as long as the overall albedo is correct and we a) don't get the darkening effect and b) do get the saturation effect at higher roughnesses.

This can simply be achieved by adding a second lobe (https://blog.selfshadow.com/publications/s2017-shading-course/imageworks/s2017_pbs_imageworks_slides_v2.pdf) or scaling the single-scattering GGX lobe (https://blog.selfshadow.com/publications/turquin/ms_comp_final.pdf). Both approaches require the same precomputation and produce outputs of comparable quality, so I went for the simple albedo scaling since it's easier to implement and more efficient.

Overall, the results are pretty good: All scenarios that I tested (Glossy BSDF, Glass BSDF, Principled BSDF with metallic or transmissive = 1) pass the white furnace test (a material with pure-white color in front of a pure-white background should be indistinguishable from the background if it preserves energy), and the overall albedo for non-white materials matches that produced by the real multi-scattering code (with the expected saturation increase as the roughness increases).

In order to produce the precomputed tables, the PR also includes a utility that computes them. This is not built by default, since there's no reason for a user to run it (it only makes sense for documentation/reproducibility purposes and when making changes to the microfacet models).

Pull Request: https://projects.blender.org/blender/blender/pulls/107958
2023-06-05 02:20:57 +02:00
Brecht Van Lommel
36e5157693 Cleanup: remove redundant lerp function, mix already does the same 2023-05-12 21:00:52 +02:00
Weizhen Huang
7484a1504d Cleanup: rename function
The name #ensure_valid_reflection seems to indicate that the resulted
reflection must be valid, whereas in the reality it only ensure validity
for specular reflections. The new name matches the behavior better.
2023-03-20 14:35:02 +01:00
Weizhen Huang
dfe7b839bc Cycles: only apply function #ensure_valid_reflection to glossy materials
This function checks if the shading normal would result in an invalid reflection into the lower hemisphere; if it is the case, the function raises the shading normal just enough so that the specular reflection lies above the surface. This is a trick to prevent dark regions at grazing angles caused by normal/bump maps. However, the specular direction is not a good representation for a diffuse material, applying this function sometimes brightens the result too much and causes unexpected results. This patch applies the function to only glossy materials instead.

Pull Request: #105776
2023-03-20 14:35:02 +01:00
Weizhen Huang
70f3382c45 Refactor: simplify computations in function #ensure_valid_reflection
Actually both potential roots lie in the interval [0, 1], so the
function ended up checking both roots all the time.
The new implementation explains why only one of the roots is valid; it
saves two square roots and a bunch of other computations.
2023-03-20 14:35:02 +01:00
Lukas Stockner
9139983f94 Cycles: Implement MaterialX OSL microfacet closures
This commit implements three OSL microfacet closures that are needed to support
MaterialX: dielectric_bsdf, conductor_bsdf and generalized_schlick_bsdf.

Internally these map to existing microfacet closures, only the Fresnel term is
different.
2023-03-05 19:52:07 +01:00
Lukas Stockner
5f9b518a8b Cycles: Use per-microfacet Fresnel term for Glass closures
This commit replaces the current Glass approach, where Glass is a virtual closure
that gets replaced with a Glossy and a Refractive closure, with a combined
closure that handles Fresnel after sampling the microfacet. That way, the Fresnel
term is more accurate since it accounts for the microfacet normal, not the
shading normal.

Also updates the BSDF sampling to use a 3D sampler now, since we need two
dimensions to pick the microfacet normal and then a third dimension to pick
reflection/refraction. This can also be used to get rid of the LCG in the
Principled Hair BSDF, which means we can remove it altogether once MultiGGX is
gone.

Also, "sharp" is now supported as a microfacet distribution in OSL, and 2
is supported as the "refract" argument to microfacet() in order to get glass.
2023-03-05 19:52:07 +01:00
Campbell Barton
731c3efd97 Cleanup: format 2023-02-06 12:32:45 +11:00
Lukas Stockner
73000c792d Cycles: Reorganize Fresnel handling in Microfacet closures
This is both a cleanup and a preparation for the Principled v2 changes.
Notable changes:
- Clearcoat weight is now folded into the closure weight, there's no reason
  to track this separately.
- There's a general-purpose helper for computing a Closure's albedo, which is
  currently used by the denoising albedo and diffuse/gloss/transmission color
  passes.
- The d/g/t color passes didn't account for closure albedo before, this means
  that e.g. metallic shaders with Principled v2 now have their color texture
  included in the glossy color pass. Also fixes T104041 (sheen albedo).
- Instead of precomputing and storing the albedo during shader setup, compute
  it when needed. This is technically redundant since we still need to compute
  it on shader setup to adjust the sample weight, but the operation is cheap
  enough that freeing up the storage seems worth it.
- Future changes (Principled v2) are easier to integrate since the Fresnel
  handling isn't all over the place anymore.
- Fresnel handling in the Multiscattering GGX code is still ugly, but since
  removing that entirely is the next step, putting effort into cleaning it up
  doesn't seem worth it.
- Apart from the d/g/t color passes, no changes to render results are expected.

Differential Revision: https://developer.blender.org/D17101
2023-02-03 21:03:48 +01:00
Brecht Van Lommel
e949d6da5b Cycles: simplify handling of ray differentials
* Store compact ray differentials in ShaderData and compute full differentials
  on demand. This reduces register pressure on the GPU.
* Remove BSDF differential code that was effectively doing nothing as the
  differential orientation was discarded when making it compact.

This gives a 1-5% speedup with RTX A6000 + OptiX in our benchmarks, with the
bigger speedups in simpler scenes.

Renders appear to be identical except for the Both displacement option that
does both displacement and bump.

Differential Revision: https://developer.blender.org/D15677
2022-08-15 13:48:02 +02:00
Andrii Symkin
d832d993c5 Cycles: add new Spectrum and PackedSpectrum types
These replace float3 and packed_float3 in various places in the kernel where a
spectral color representation will be used in the future. That representation
will require more than 3 channels and conversion to from/RGB. The kernel code
was refactored to remove the assumption that Spectrum and RGB colors are the
same thing.

There are no functional changes, Spectrum is still a float3 and the conversion
functions are no-ops.

Differential Revision: https://developer.blender.org/D15535
2022-08-09 16:49:34 +02:00
Brecht Van Lommel
9cfc7967dd Cycles: use SPDX license headers
* Replace license text in headers with SPDX identifiers.
* Remove specific license info from outdated readme.txt, instead leave details
  to the source files.
* Add list of SPDX license identifiers used, and corresponding license texts.
* Update copyright dates while we're at it.

Ref D14069, T95597
2022-02-11 17:47:34 +01:00
Brecht Van Lommel
d7d40745fa Cycles: changes to source code folders structure
* Split render/ into scene/ and session/. The scene/ folder now contains the
  scene and its nodes. The session/ folder contains the render session and
  associated data structures like drivers and render buffers.
* Move top level kernel headers into new folders kernel/camera/, kernel/film/,
  kernel/light/, kernel/sample/, kernel/util/
* Move integrator related kernel headers into kernel/integrator/
* Move OSL shaders from kernel/shaders/ to kernel/osl/shaders/

For patches and branches, git merge and rebase should be able to detect the
renames and move over code to the right file.
2021-10-26 15:36:39 +02:00
Michael Jones
a0f269f682 Cycles: Kernel address space changes for MSL
This is the first of a sequence of changes to support compiling Cycles kernels as MSL (Metal Shading Language) in preparation for a Metal GPU device implementation.

MSL requires that all pointer types be declared with explicit address space attributes (device, thread, etc...). There is already precedent for this with Cycles' address space macros (ccl_global, ccl_private, etc...), therefore the first step of MSL-enablement is to apply these consistently. Line-for-line this represents the largest change required to enable MSL. Applying this change first will simplify future patches as well as offering the emergent benefit of enhanced descriptiveness.

The vast majority of deltas in this patch fall into one of two cases:

- Ensuring ccl_private is specified for thread-local pointer types
- Ensuring ccl_global is specified for device-wide pointer types

Additionally, the ccl_addr_space qualifier can be removed. Prior to Cycles X, ccl_addr_space was used as a context-dependent address space qualifier, but now it is either redundant (e.g. in struct typedefs), or can be replaced by ccl_global in the case of pointer types. Associated function variants (e.g. lcg_step_float_addrspace) are also redundant.

In cases where address space qualifiers are chained with "const", this patch places the address space qualifier first. The rationale for this is that the choice of address space is likely to have the greater impact on runtime performance and overall architecture.

The final part of this patch is the addition of a metal/compat.h header. This is partially complete and will be extended in future patches, paving the way for the full Metal implementation.

Ref T92212

Reviewed By: brecht

Maniphest Tasks: T92212

Differential Revision: https://developer.blender.org/D12864
2021-10-14 16:14:43 +01:00
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
OmarSquircleArt
613b37bc2c Shading: Add More Features To The Voronoi Node.
This patch allows the Voronoi node to operate in 1D, 2D, and 4D space.
It also adds a Randomness input to control the randomness of the texture.
Additionally, it adds three new modes of operation:

- Smooth F1: A smooth version of F1 Voronoi with no discontinuities.
- Distance To Edge: Returns the distance to the edges of the cells.
- N-Sphere Radius: Returns the radius of the n-sphere inscribed in
the cells. In other words, it is half the distance between the
closest feature point and the feature point closest to it.

And it removes the following three modes of operation:

- F3.
- F4.
- Cracks.

The Distance metric is now called Euclidean, and it computes the actual
euclidean distance as opposed to the old method of computing the squared
euclidean distance.

This breaks backward compatibility in many ways, including the base case.

Reviewers: brecht, JacquesLucke

Differential Revision: https://developer.blender.org/D5743
2019-09-12 13:09:31 +02:00
Campbell Barton
c47d669f24 Cleanup: comments (long lines) in cycles 2019-05-01 21:41:07 +10:00
Campbell Barton
e12c08e8d1 ClangFormat: apply to source, most of intern
Apply clang format as proposed in T53211.

For details on usage and instructions for migrating branches
without conflicts, see:

https://wiki.blender.org/wiki/Tools/ClangFormat
2019-04-17 06:21:24 +02:00
Sergey Sharybin
cb4b5e12ab Cycles: Cleanup, spacing after preprocessor
It is supposed to be two spaces before comment stating which if
else/endif statements corresponds to. Was mainly violated in the
header guards.
2018-11-09 11:34:54 +01:00
Campbell Barton
1daa20ad9f Cleanup: strip trailing space for cycles 2018-07-06 10:17:58 +02:00
Pascal Schoen
8825a8e951 Squashed commit of the following:
commit 90778901c9ea1e16d5907981e91bceba25ff207d
Merge: 76eebd9 3bf0026
Author: Schoen <schoepas@deher1m1598.emea.adsint.biz>
Date:   Mon Apr 3 07:52:05 2017 +0200

    Merge branch 'master' into cycles_disney_brdf

commit 76eebd9379a5dad519ff01cf215fbe3db6de931e
Author: Schoen <schoepas@deher1m1598.emea.adsint.biz>
Date:   Thu Mar 30 15:34:20 2017 +0200

    Updated copyright for the new files.

commit 013f4a152a3898946ba5c616141c6e44d928ccfd
Author: Schoen <schoepas@deher1m1598.emea.adsint.biz>
Date:   Thu Mar 30 15:32:55 2017 +0200

    Switched from multiplication of base and subsurface color to blending
    between them using the subsurface parameter.

commit 482ec5d1f20ceabc9cbda4838d4ae37d1d673458
Author: Schoen <schoepas@deher1m1598.emea.adsint.biz>
Date:   Mon Mar 13 15:47:12 2017 +0100

    Fixed a bug that caused an additional white diffuse closure call when using
    path tracing.

commit 26e906d162a6a8d67f2ebc8880993fcbab69559e
Merge: 0593b8c 223aff9
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Feb 6 11:32:31 2017 +0100

    Merge branch 'master' into cycles_disney_brdf

commit 0593b8c51bf7db0ed5ca92ed6f68d0d984dad0dd
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Feb 6 11:30:36 2017 +0100

    Fixed the broken GLSL shader and implemented the Disney BRDF in the
    real-time view port.

commit 8c7e11423be640dc44b1807912058480710e51f4
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Fri Feb 3 14:24:05 2017 +0100

    Fix to comply strict compiler flags and some code cleanup

commit 17724e9d2dbffb1aaa61401224ecbf2349c1dac3
Merge: 379ba34 520afa2
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Jan 24 09:59:58 2017 +0100

    Merge branch 'master' into cycles_disney_brdf

commit 379ba346b0acd1ea779365b940fcd01f5ba1165f
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Jan 24 09:28:56 2017 +0100

    Renamed the Disney BSDF to Principled BSDF.

commit f80dcb4f34f1dc41841ced5965787fc26ace22a2
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Fri Dec 2 13:55:12 2016 +0100

    Removed reflection call when roughness is low because of artifacts.

commit 732db8a57f6d4e5d6f44bbad176c15fd55377f0a
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Wed Nov 16 09:22:25 2016 +0100

    Indication if to use fresnel is now handled via the type of the BSDF.

commit 0103659f5e705b314cde98b0e4a01c14c55acd5e
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Fri Nov 11 13:04:11 2016 +0100

    Fixed an error in the clearcoat where it appeared too bright for default
    light sources (like directional lights)

commit 0aa68f533529c9fd197a3ab0427f9e41a15456b9
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Nov 7 12:04:38 2016 +0100

    Resolved inconsistencies in using tabs and spaces

commit f5897a9494e352de274b99e7bee971336c0dc386
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Nov 7 08:13:41 2016 +0100

    Improved the clearcoat part by using GTR1 instead of GTR2

commit 3dfc240e61b3d4d0e7c476989792e4ada869ce91
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Oct 31 11:31:36 2016 +0100

    Use reflection BSDF for glossy reflections when roughness is 0.0 to
    reduce computational expense and some code cleanup

    Code cleanup includes:
    - Code style cleanup and removed unused code
    - Consolidated code in the bsdf_microfacet_multi_impl.h to reduce
      some computational expense

commit a2dd0c5fafdabe1573299170fb3be98a3e46d17a
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Wed Oct 26 08:51:10 2016 +0200

    Fixed glossy reflections and refractions for low roughness values and
    cleaned up the code.

    For low roughness values, the reflections had some strange behavior.

commit 981737591231a1a5a1c85950950580b65d029505
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Oct 25 12:37:40 2016 +0200

    Removed default values in setup functions and added extra functions for
    GGX with fresnel.

commit bbc5d9d4527346a74155cf17be21fb02ee3e0779
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Oct 25 11:09:36 2016 +0200

    Switched from uniform to cosine hemisphere sampling for the diffuse and
    the sheen part.

commit d52d8f2813d64363713f11160a6c725d4cafbcfa
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Oct 24 16:17:13 2016 +0200

    Removed the color parameters from the diffuse and sheen shader and use
    them as closure weights instead.

commit 8f3d92738532ad867a0a3543c00393626ab8f6ec
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Oct 24 09:57:06 2016 +0200

    Fixed the issue with artifacts when using anisotropy without linking the
    tangent input to a tangent node.

commit d93f680db9acaaade0354b34857a3ccaf348557f
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Oct 24 09:14:51 2016 +0200

    Added subsurface radius parameter to control the per color channel
    effection radius of the subsurface scattering.

commit c708c3e53b323773fc852bdc239bc51e157dcaef
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Oct 24 08:14:10 2016 +0200

    Rearranged the inputs of the shader.

commit dfbfff9c389074d3e5c1f49dd38a95e9b317eb1f
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Fri Oct 21 09:27:05 2016 +0200

    Put spaces in the parameter names of the shader node

commit e5a748ced17c8f59e5e73309096adeea3ba95e04
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Fri Oct 21 08:51:20 2016 +0200

    Removed code that isn't in use anymore

commit 75992bebc128c8b44cab4f0d8855603787f57260
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Fri Oct 21 08:50:07 2016 +0200

    Code style cleanup

commit 4dfcf455f7769752044e051b399fb6a5dfcd0e22
Merge: 243a0e3 2cd6a89
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Thu Oct 20 10:41:50 2016 +0200

    Merge branch 'master' into cycles_disney_brdf

commit 243a0e3eb80ef82704d5ea2657384c3a4b9fb497
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Thu Oct 20 10:01:45 2016 +0200

    Switching between OSL and SVM is more consistant now when using Disney
    BSDF.

    There were some minor differences in the OSL implementation, e.g. the
    refraction roughness was missing.

commit 2a5ac509223c838285a00c4c12775567666e7154
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Sep 27 09:17:57 2016 +0200

    Fixed a bug that caused transparency to be always white when using OSL and
    selecting GGX as distribution of the Disney BSDF

commit e1fa8623915407cea942a07fd0a106b04e113c09
Merge: d0530a8 7f76f6f
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Sep 27 08:59:32 2016 +0200

    Merge branch 'master' into cycles_disney_brdf

commit d0530a8af0e076c0aca4c9a61b0a64cada45ac4d
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Sep 27 08:53:18 2016 +0200

    Cleanup the Disney BSDF implementation and removing unneeded files.

commit 3f4fc826bd9c1f47c694c0f6b2947daf5b524b1a
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Sep 27 08:36:07 2016 +0200

    Unified the OSL implementation of the Disney clearcoat as a simple
    microfacet shader like it was previously done in SVM

commit 4d3a0032ecea99031979f342bfd5f66ea5a8625a
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Sep 26 12:35:36 2016 +0200

    Enhanced performance for Disney materials without subsurface scattering

commit 3cd5eb56cf5c9006837f111c8866e4c6e1c2a6fd
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Fri Sep 16 08:47:56 2016 +0200

    Fixed a bug in the Disney BSDF that caused specular reflections to be too
    bright and diffuse is now reacting to the roughness again

    - A normalization for the fresnel was missing which caused the specular
      reflections to become too bright for the single-scatter GGX
    - The roughness value for the diffuse BSSRDF part has always been
      overwritten and thus always 0
    - Also the performance for refractive materials with roughness=0.0 has
      been improved

commit 7cb37d711938e5626651db21f20da50edd96abaf
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Thu Sep 8 12:24:43 2016 +0200

    Added selection field to the Disney BSDF node for switching between
    "Multiscatter GGX" and "GGX"

    In the "GGX" mode there is an additional parameter for changing the
    refraction roughness for materials with smooth surfaces and rough interns
    (e.g. honey). With the "Multiscatter GGX" this effect can't be produced at
    the moment and so here will be no separation of the two roughness values.

commit cdd29d06bb86672ed0779eefb8eee95796b8f939
Merge: 02c315a b40d1c1
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Sep 6 15:59:05 2016 +0200

    Merge branch 'master' into cycles_disney_brdf

commit 02c315aeb0f0d7bb429d4396912e03dbb8a77340
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Sep 6 15:16:09 2016 +0200

    Implemented the OSL part of the Disney shader

commit 5f880293aeeacf269032824248b46d613691a36c
Merge: 630b80e b399a6d
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Fri Sep 2 10:53:36 2016 +0200

    Merge branch 'master' into cycles_disney_brdf

commit 630b80e08b6acf83834bc95264af4ccdbbc5f82c
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Fri Sep 2 10:52:13 2016 +0200

    Fresnel in the microfacet multiscatter implementation improved

commit 0d9f4d7acb2de65d1c98d425cea4bf364795c155
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Fri Aug 26 11:11:05 2016 +0200

    Fixed refraction roughness problem (refractions were always 100% rough)
    and set IOR of clearcoat to 1.5

commit 9eed34c7d980e1b998df457c4f76021162c80f78
Merge: ef29aae ae475e3
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Aug 16 15:22:32 2016 +0200

    Merge branch 'master' into cycles_disney_brdf

commit ef29aaee1af8074e0228c480d962700e97ea5b36
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Aug 16 15:17:12 2016 +0200

    Implemented the fresnel in the multi-scatter GGX for the Disney BSDF

    - The specular/metallic part uses the multi-scatter GGX
    - The fresnel of the metallic part is controlled by the specular value
    - The color of the reflection part when using transparency can be
      controlled by the specularTint value

commit 88567af085ac94119b98c95246b6d6f63161bc01
Merge: cc267e5 285e082
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Wed Aug 3 15:05:09 2016 +0200

    Merge branch 'master' into cycles_disney_brdf

commit cc267e52f20d036a66aeeff127ee1c856f7c651b
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Wed Aug 3 15:00:25 2016 +0200

    Implemented the Disney clearcoat as a variation of the microfacet bsdf,
    removed the transparency roughness again and added an input for
    anisotropic rotations

commit 81f6c06b1f53180bf32a5c11ac1fa64e2b6abf52
Merge: ece5a08 7065022
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Wed Aug 3 11:42:02 2016 +0200

    Merge branch 'master' into cycles_disney_brdf

commit ece5a08e0d6e51a83c223ea87346134216e5b34e
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Jul 26 16:29:21 2016 +0200

    Base color now applied again to the refraction of transparent Disney
    materials

commit e3aff6849e06853c56da7bd610210dcab70e6070
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Jul 26 16:05:19 2016 +0200

    Added subsurface color parameter to the Disney shader

commit b3ca6d8a2f4f866b323fc2df0a3beff577218c27
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Jul 26 12:30:25 2016 +0200

    Improvement of the SSS in the Disney shader

     * Now the bump normal is correctly used for the SSS.
     * SSS in Disney uses the Disney diffuse shader

commit d68729300ee557e90a8e7e4be6eb8ef98db80fe2
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Jul 26 12:23:13 2016 +0200

    Better calculation of the Disney diffuse part

    Now the values for NdotL und NdotV are clamped to 0.0f for a better look
    when using normal maps

commit cb6e500b12e7bce884d3db19ee138c975c215f2d
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Jul 25 16:26:42 2016 +0200

    Now one can disable specular reflactions again by setting specular and
    metallic to 0 (cracked this in the previous commit)

commit bfb9cb11b548103369de2a46ce18b4ddf661362c
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Jul 25 16:11:07 2016 +0200

    fixed the Disney SSS and cleaned the initialization of the Disney shaders

commit 642c0fdad12548c1a2ccbf595bae3a995d3022f7
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Jul 25 16:09:55 2016 +0200

    fixed an error that was caused by the missing LABEL_REFLECT in the Disney
    diffuse shader

commit c10b484dcad3412c34455736e9656cd38716bcb0
Author: Jens Verwiebe <info@jensverwiebe.de>
Date:   Fri Jul 22 01:15:21 2016 +0200

    Rollback attempt to fix sss crashing, it prevented crash by disabling sss completely, thus useless

commit 462bba3f97fcc41834e0e20cc806a7958e5106f5
Author: Jens Verwiebe <info@jensverwiebe.de>
Date:   Thu Jul 21 23:11:59 2016 +0200

    Add an undef for sc_next for safety

commit 32d348577d69be251aa04110c5f6156cd2645f48
Author: Jens Verwiebe <info@jensverwiebe.de>
Date:   Thu Jul 21 00:15:48 2016 +0200

    Attempt to fix Disney SSS

commit dbad91ca6d46f5a4a6f2ba7ed4c811ffa723942f
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Wed Jul 20 11:13:00 2016 +0200

    Added a roughness parameter for refractions (for scattering of the rays
    within an object)

    With this, one can create a translucent material with a smooth surface and
    with a milky look.

    The final refraction roughness has to be calculated using the surface
    roughness and the refraction roughness because those two are correlated
    for refractions. If a ray hits a rough surface of a translucent material,
    it is scattered while entering the surface. Then it is scattered further
    within the object. The calculation I'm using is the following:

    RefrRoughnessFinal = 1.0 - (1.0 - Roughness) * (1.0 - RefrRoughness)

commit 50ea5e3e34394a727e3cceb6203adb48834a9ab7
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue Jun 7 10:24:50 2016 +0200

    Disney BSDF is now supporting CUDA

commit 10974cc826a4bfa8fb3ef59177abf0b0dc441065
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue May 31 11:18:07 2016 +0200

    Added parameters IOR and Transparency for refractions

    With this, the Disney BRDF/BSSRDF is extended by the BTDF part.

commit 218202c0905a4ec93ee19850360d1a39966d2c25
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon May 30 15:08:18 2016 +0200

    Added an additional normal for the clearcoat

    With this normal one can simulate a thin layer of clearcoat by applying a
    smoother normal map than the original to this input

commit dd139ead7e04aa87a894ccf3732cfce711258ff1
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon May 30 12:40:56 2016 +0200

    Switched to the improved subsurface scattering from Christensen and
    Burley

commit 11160fa4e1c32230119d4506e7e9fd3da2ab37f2
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon May 30 10:16:30 2016 +0200

    Added Disney Sheen shader as a preparation to get to a BSSRDF

commit cee4fe0cc94515ee60d4afa4d4e10c41003f1579
Merge: 4f955d0 6b5bab6
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon May 30 09:08:09 2016 +0200

    Merge branch 'cycles_disney_brdf' of git.blender.org:blender into cycles_disney_brdf

    Conflicts:
    	intern/cycles/kernel/closure/bsdf_disney_clearcoat.h
    	intern/cycles/kernel/closure/bsdf_disney_diffuse.h
    	intern/cycles/kernel/closure/bsdf_disney_specular.h
    	intern/cycles/kernel/closure/bsdf_util.h
    	intern/cycles/kernel/osl/CMakeLists.txt
    	intern/cycles/kernel/osl/bsdf_disney_clearcoat.cpp
    	intern/cycles/kernel/osl/bsdf_disney_diffuse.cpp
    	intern/cycles/kernel/osl/bsdf_disney_specular.cpp
    	intern/cycles/kernel/osl/osl_closures.h
    	intern/cycles/kernel/shaders/node_disney_bsdf.osl
    	intern/cycles/render/nodes.cpp
    	intern/cycles/render/nodes.h

commit 4f955d052358206209454decf2c3539e6a21b42f
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue May 24 16:38:23 2016 +0200

    SVM and OSL are both working for the simple version of the Disney BRDF

commit 1f5c41874b01ad297eb8a6bad9985296c6c0a6e1
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue May 24 09:58:50 2016 +0200

    Disney node can be used without SVM and started to cleanup the OSL implementation

    There is still some wrong behavior for SVM for the Schlick Fresnel part at the
    specular and clearcoat

commit d4b814e9304ebb44cc7c291cd83f7b7cdebcd152
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Wed May 18 10:22:29 2016 +0200

    Switched from a parameter struct for Disney parameters to ShaderClosure params

commit b86a1f5ba5019c7818153cb70b49f5f7a0bc52a0
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Wed May 18 10:19:57 2016 +0200

    Added additional variables for storing parameters in the ShaderClosure struct

commit 585b88623695fa07dfca9c9909d6d9184c3519c8
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue May 17 12:03:17 2016 +0200

    added output parameter to the DisneyBsdfNode

    That has been forgotten after removing the inheritance of BsdfNode

commit f91a28639884cbda7804715b910d64abba0718ef
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue May 17 10:40:48 2016 +0200

    removed BsdfNode class inheritance for DisneyBsdfNode

    That's due to a naming difference. The Disney BSDF uses the name 'Base Color'
    while the BsdfNode had a 'Color' input. That caused a text message to be
    printed while rendering.

commit 30da91c9c51d8cbc6a7564c7aaa61c9efe2ab654
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Wed May 4 16:08:10 2016 +0200

    disney implementation cleaned

commit 30d41da0f0352fad29375a395ffcb9cb7891eeb1
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Wed May 4 13:23:07 2016 +0200

    added the disney brdf as a shader node

commit 1f099fce249cb35e949cc629f7cca2167fca881a
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue May 3 16:54:49 2016 +0200

    added clearcoat implementation

commit 00a1378b98e435e9cdbfbac86eb974c19b2a8151
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Fri Apr 29 22:56:49 2016 +0200

    disney diffuse und specular implemented

commit 6baa7a7eb787638661cddad0c4e7f78bd3a8fa5c
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Apr 18 15:21:32 2016 +0200

    disney diffuse is working correctly

commit d8fa169bf3caf71c40a124101b33dee6c510188e
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Apr 18 08:41:53 2016 +0200

    added vessel for disney diffuse shader

commit 6b5bab6cecde153122625cf8dc10e4209ed1eb0f
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Wed May 18 10:22:29 2016 +0200

    Switched from a parameter struct for Disney parameters to ShaderClosure params

commit f6499c2676e074a36033627ffc7540107777630d
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Wed May 18 10:19:57 2016 +0200

    Added additional variables for storing parameters in the ShaderClosure struct

commit 7100640b65c2ff5447a18c01fc4e93594b4f486a
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue May 17 12:03:17 2016 +0200

    added output parameter to the DisneyBsdfNode

    That has been forgotten after removing the inheritance of BsdfNode

commit 419ee5441100a906b4b3fd8373cb768a71bfdfe6
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue May 17 10:40:48 2016 +0200

    removed BsdfNode class inheritance for DisneyBsdfNode

    That's due to a naming difference. The Disney BSDF uses the name 'Base Color'
    while the BsdfNode had a 'Color' input. That caused a text message to be
    printed while rendering.

commit 6006f91e8730f78df5874f808690d3908db103ab
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Wed May 4 16:08:10 2016 +0200

    disney implementation cleaned

commit 0ed08959141fc7c5f8c6e37c6552ecb9fcc5749c
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Wed May 4 13:23:07 2016 +0200

    added the disney brdf as a shader node

commit 0630b742d71c658915575a4a71a325094a0fc313
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Tue May 3 16:54:49 2016 +0200

    added clearcoat implementation

commit 9f3d39744b85619750c79c901f678b8c07fe0ee2
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Fri Apr 29 22:56:49 2016 +0200

    disney diffuse und specular implemented

commit 9b262063767d6b05a617891c967d887d21bfb177
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Apr 18 15:21:32 2016 +0200

    disney diffuse is working correctly

commit 4711a3927dfcadaa1c36de0ba78fc304fac1dc8a
Author: Pascal Schoen <pascal_schoen@gmx.net>
Date:   Mon Apr 18 08:41:53 2016 +0200

    added vessel for disney diffuse shader

Differential Revision: https://developer.blender.org/D2313
2017-04-18 11:43:09 +02:00
Lukas Stockner
d9281a6332 Cycles: Fix three numerical issues in the fresnel, normal map and Beckmann code
- In fresnel_dielectric, the differentials calculation sometimes divided by zero.
- When the normal map was (0.5, 0.5, 0.5), the code would try to normalize a zero vector. Now, it just uses the regular normal as a fallback.
- The approximate error function used in Beckmann sampling sometimes overflowed to inf while calculating r^16. The final value is 1 - 1/r^16, however,
  so now it just returns 1 if the computation would overflow otherwise.
2016-07-16 20:54:14 +02:00
Lukas Stockner
23c276832b Cycles: Add multi-scattering, energy-conserving GGX as an option to the Glossy, Anisotropic and Glass BSDFs
This commit adds a new distribution to the Glossy, Anisotropic and Glass BSDFs that implements the
multiple-scattering microfacet model described in the paper "Multiple-Scattering Microfacet BSDFs with the Smith Model".

Essentially, the improvement is that unlike classical GGX, which only models single scattering and assumes
the contribution of multiple bounces to be zero, this new model performs a random walk on the microsurface until
the ray leaves it again, which ensures perfect energy conservation.

In practise, this means that the "darkening problem" - GGX materials becoming darker with increasing
roughness - is solved in a physically correct and efficient way.

The downside of this model is that it has no (known) analytic expression for evalation. However, it can be
evaluated stochastically, and although the correct PDF isn't known either, the properties of MIS and the
balance heuristic guarantee an unbiased result at the cost of slightly higher noise.

Reviewers: dingto, #cycles, brecht

Reviewed By: dingto, #cycles, brecht

Subscribers: bliblubli, ace_dragon, gregzaal, brecht, harvester, dingto, marcog, swerner, jtheninja, Blendify, nutel

Differential Revision: https://developer.blender.org/D2002
2016-06-23 22:57:26 +02:00
Thomas Dinges
da3be518b6 Comment out SVM fresnel_conductor() function for now, still unused. 2014-09-07 21:13:00 +02:00
Thomas Dinges
aa8d25bf09 Cycles / OSL: Add a conductive fresnel shader template.
This adds a fresnel conductive OSL preset to the Text Editor. Based on a patch by Lukas Stockner.
Differential revision: https://developer.blender.org/D145

See the differential for details.
2014-09-07 18:28:59 +02:00
Campbell Barton
dc13969e48 Style cleanup: indentation, braces 2014-05-05 02:19:08 +10:00
Brecht Van Lommel
c18712e868 Cycles: change __device and similar qualifiers to ccl_device in kernel code.
This to avoids build conflicts with libc++ on FreeBSD, these __ prefixed values
are reserved for compilers. I apologize to anyone who has patches or branches
and has to go through the pain of merging this change, it may be easiest to do
these same replacements in your code and then apply/merge the patch.

Ref T37477.
2013-11-18 08:48:15 +01:00
Thomas Dinges
9c6deff652 Cycles / Fresnel:
* Avoid redundant assignment and use correct Normal for Ray Differentials.
2013-05-26 22:34:45 +00:00
Thomas Dinges
4475de5bd8 Cycles:
* Revert part of r56832, if code gets more complicated, it's better to keep it more logical here.
2013-05-16 15:47:09 +00:00
Brecht Van Lommel
06888b7beb Cycles OSL minor optimizations: recycle shading context, don't do memory
allocations for trace data, avoid some virtual function calls. Only helps
a few percentages.
2012-12-15 10:18:42 +00:00