This is an implementation of thin film iridescence in the Principled BSDF based on "A Practical Extension to Microfacet Theory for the Modeling of Varying Iridescence".
There are still several open topics that are left for future work:
- Currently, the thin film only affects dielectric Fresnel, not metallic. Properly specifying thin films on metals requires a proper conductive Fresnel term with complex IOR inputs, any attempt of trying to hack it into the F82 model we currently use for the Principled BSDF is fundamentally flawed. In the future, we'll add a node for proper conductive Fresnel, including thin films.
- The F0/F90 control is not very elegantly implemented right now. It fundamentally works, but enabling thin film while using a Specular Tint causes a jump in appearance since the models integrate it differently. Then again, thin film interference is a physical effect, so of course a non-physical tweak doesn't play nicely with it.
- The white point handling is currently quite crude. In short: The code computes XYZ values of the reflectance spectrum, but we'd need the XYZ values of the product of the reflectance spectrum and the neutral illuminant of the working color space. Currently, this is addressed by just dividing by the XYZ values of the illuminant, but it would be better to do a proper chromatic adaptation transform or to use the proper reference curves for the working space instead of the XYZ curves from the paper.
Pull Request: https://projects.blender.org/blender/blender/pulls/118477
Transport rays that enter to another location in the scene, with
specified ray position and normal. This may be used to render portals
for visual effects, and other production rendering tricks.
This acts much like a Transparent BSDF. Render passes are passed
through, and this is affected by light path max transparent bounces.
Pull Request: https://projects.blender.org/blender/blender/pulls/114386
Extract
- Statuses for the external text editor
- Newly created enum node item
- Newly created plane track data
- Newly created custom orientation data
- Operator names in drag and drop menu (need to use operator's
translation context)
- GN attribute statistic node inputs
Disambiguate
- Single-letter colors: A and B can mean Alpha and Blue, or simply A
and B as in two operands in an operation
- Dissolve: issue reported by Tamar Mebonia in #43295
- Translate in the User Preferences. This introduces a new
BLT_I18NCONTEXT_EDITOR_PREFERENCES ("Preferences") translation
context
- Planar (reported by deathblood)
This one is incomplete, because there is currently no way to
disambiguate presets or GN fields. I don't see how either could be
achieved cleanly.
The former would need to define the context inside the preset and
evaluate the file prior to showing it in the presets menu, which
sound bad.
The latter would need to introduce an additional string inside
`FieldInput`s, which would be controversial given how little it
would be used.
Remove
- Unused translation `iface_("%s")` in toolbar
- Remove obsolete N_() tags in a few node descriptions.
Pull Request: https://projects.blender.org/blender/blender/pulls/119065
This fixes the following name collisions:
* Compositor Box/Ellipse Mask node: `width` -> `mask_width`
(also renamed the `height` property accordingly)
* Shader AOV Output node: `name` -> `aov_name`
* Geometry Color node: `color` -> `value`.
Those are breaking changes unfortunately, because looking up those property
names yielded the node-specific and not the common property. Therefore, this is
targeted at `main` instead of `4.1`.
Pull Request: https://projects.blender.org/blender/blender/pulls/119284
The `object_to_world` and `world_to_object` matrices are set during
depsgraph evaluation, calculated from the object's animated location,
rotation, scale, parenting, and constraints. It's confusing and
unnecessary to store them with the original data in DNA.
This commit moves them to `ObjectRuntime` and moves the matrices to
use the C++ `float4x4` type, giving the potential for simplified code
using the C++ abstractions. The matrices are accessible with functions
on `Object` directly since they are used so commonly. Though for write
access, directly using the runtime struct is necessary.
The inverse `world_to_object` matrix is often calculated before it's
used, even though it's calculated as part of depsgraph evaluation.
Long term we might not want to store this in `ObjectRuntime` at all,
and just calculate it on demand. Or at least we should remove the
redundant calculations. That should be done separately though.
Pull Request: https://projects.blender.org/blender/blender/pulls/118210
EEVEE-Next can only store data for a single (global) closure at a time,
which, when combined with ShaderToRGB nodes, requires extra care in the
order that closures are evaluated.
For example:

Here, after `ntree_shader_shader_to_rgba_branch` there will be 2 Diffuse
nodes (the original and a copy for the ShaderToRGB branch).
However, the generated code order will be something like this:
```
Diffuse (original)
Diffuse (copy)
ShaderToRGB // This resets closures
Mix
```
So while the original node is technically "evaluated", the closure data
is reset after ShaderToRGB.
This patch updates the code generation to ensure closure evaluation is
ordered taking ShaderToRGB branches into account, so the generated code
looks like this:
```
Diffuse (copy)
ShaderToRGB // This resets closures
Diffuse (original)
Mix
```
This also fixes ShaderToRGB support for AOVs, removes unused code, and
fixes several bugs that I've found along the way that were harmless for
EEVEE but broke EEVEE Next.
Pull Request: https://projects.blender.org/blender/blender/pulls/117767
The previous commit introduced a new `RPT_()` macro to translate
strings which are not tooltips or regular interface elements, but
longer reports or statuses.
This commit uses the new macro to translate many strings all over the
UI.
Most of it is a simple replace from `TIP_()` or `IFACE_()` to
`RPT_()`, but there are some additional changes:
- A few translations inside `BKE_report()` are removed altogether
because they are already handled by the translation system.
- Messages inside `UI_but_disable()` are no longer translated
manually, but they are handled by a new regex in the translation
system.
Pull Request: https://projects.blender.org/blender/blender/pulls/116804
Pull Request: https://projects.blender.org/blender/blender/pulls/116804
Even if related, they don't have the same performance
impact.
To avoid any performance hit, we replace the Diffuse
by a Subsurface Closure for legacy EEVEE and
use the subsurface closure only where needed for
EEVEE-Next leveraging the random sampling.
This increases the compatibility with cycles that
doesn't modulate the radius of the subsurface anymore.
This change is only present in EEVEE-Next.
This commit changes the principled BSDF code so that
it is easier to follow the flow of data.
For legacy EEVEE, the SSS switch is moved to a
`radius == -1` check.
This commit adds a new helper to define expected properties when a
target needs to use the unity build feature.
That new helper does what was already done for existing cases, and in
addition add the target to the Ninja 'heavy' pooljobs if relevant.
Pull Request: https://projects.blender.org/blender/blender/pulls/116791
Along with the 4.1 libraries upgrade, we are bumping the clang-format
version from 8-12 to 17. This affects quite a few files.
If not already the case, you may consider pointing your IDE to the
clang-format binary bundled with the Blender precompiled libraries.