In Cycles the volume transmittance is already composited into the color
passes. In Eevee the volume transmittance pass was separate and needed
to be composited in the compositor. This patch adds the volume
transmittance pass direct in the next render passes:
* Diffuse Color
* Specular Color
* Emission
* Environment
This patch includes the removal of the volume transmittance render pass.
It also renames the volume render passes to match Cycles. The setting
themselves aren't unified.
Maniphest Tasks: T81134
When compiling on Windows, the following warnings occur:
```[3468/4560] Building C object source\blender\draw\CMakeFiles\bf_draw.dir\engines\eevee\eevee_cryptomatte.c.obj
C:\blender-git\blender\source\blender\draw\engines\eevee\eevee_cryptomatte.c(306): warning C4047: 'function': 'bool' differs in levels of indirection from 'void *'
C:\blender-git\blender\source\blender\draw\engines\eevee\eevee_cryptomatte.c(306): warning C4024: 'eevee_cryptomatte_shading_group_create': different types for formal and actual parameter 5```
As @Severin pointed out [here](https://developer.blender.org/rB76a0b322e4d3244e59a154c8255b84a4fbc33117#288960), this is due to the last two arguments being flipped. This diff corrects the order.
Reviewed By: Severin, fclem
Differential Revision: https://developer.blender.org/D9809
Cryptomatte is a standard to efficiently create mattes for compositing. The
renderer outputs the required render passes, which can then be used in the
compositor to create masks for specified objects. Unlike the Material and Object
Index passes, the objects to isolate are selected in compositing, and mattes
will be anti-aliased.
Cryptomatte was already available in Cycles this patch adds it to the EEVEE
render engine. Original specification can be found at
https://raw.githubusercontent.com/Psyop/Cryptomatte/master/specification/IDmattes_poster.pdf
**Accurate mode**
Following Cycles, there are two accuracy modes. The difference between the two
modes is the number of render samples they take into account to create the
render passes. When accurate mode is off the number of levels is used. When
accuracy mode is active, the number of render samples is used.
**Deviation from standard**
Cryptomatte specification is based on a path trace approach where samples and
coverage are calculated at the same time. In EEVEE a sample is an exact match on
top of a prepared depth buffer. Coverage is at that moment always 1. By sampling
multiple times the number of surface hits decides the actual surface coverage
for a matte per pixel.
**Implementation Overview**
When drawing to the cryptomatte GPU buffer the depth of the fragment is matched
to the active depth buffer. The hashes of each cryptomatte layer is written in
the GPU buffer. The exact layout depends on the active cryptomatte layers. The
GPU buffer is downloaded and integrated into an accumulation buffer (stored in
CPU RAM).
The accumulation buffer stores the hashes + weights for a number of levels,
layers per pixel. When a hash already exists the weight will be increased. When
the hash doesn't exists it will be added to the buffer.
After all the samples have been calculated the accumulation buffer is processed.
During this phase the total pixel weights of each layer is mapped to be in a
range between 0 and 1. The hashes are also sorted (highest weight first).
Blender Kernel now has a `BKE_cryptomatte` header that access to common
functions for cryptomatte. This will in the future be used by the API.
* Alpha blended materials aren't supported. Alpha blended materials support in
render passes needs research how to implement it in a maintainable way for any
render pass.
This is a list of tasks that needs to be done for the same release that this
patch lands on (Blender 2.92)
* T82571 Add render tests.
* T82572 Documentation.
* T82573 Store hashes + Object names in the render result header.
* T82574 Use threading to increase performance in accumulation and post
processing.
* T82575 Merge the cycles and EEVEE settings as they are identical.
* T82576 Add RNA to extract the cryptomatte hashes to use in python scripts.
Reviewed By: Clément Foucault
Maniphest Tasks: T81058
Differential Revision: https://developer.blender.org/D9165
This patch adds support for AOVs in EEVEE. AOV Outputs can be defined in the
render pass tab and used in shader materials. Both Object and World based
shaders are supported. The AOV can be previewed in the viewport using the
renderpass selector in the shading popover.
AOV names that conflict with other AOVs are automatically corrected. AOV
conflicts with render passes get a warning icon. The reason behind this is that
changing render engines/passes can change the conflict, but you might not notice
it. Changing this automatically would also make the materials incorrect, so best
to leave this to the user.
**Implementation**
The patch adds a copies the AOV structures of Cycles into Blender. The goal is
that the Cycles will use Blenders AOV defintions. In the Blender kernel
(`layer.c`) the logic of these structures are implemented.
The GLSL shader of any GPUMaterial can hold multiple outputs (the main output
and the AOV outputs) based on the renderPassUBO the right output is selected.
This selection uses an hash that encodes the AOV structure. The full AOV needed
to be encoded when actually drawing the material pass as the AOV type changes
the behavior of the AOV. This isn't known yet when the GLSL is compiled.
**Future Developments**
* The AOV definitions in the render layer panel isn't shared with Cycles.
Cycles should be migrated to use the same viewlayer aovs. During a previous
attempt this failed as the AOV validation in cycles and in Blender have
implementation differences what made it crash when an aov name was invalid.
This could be fixed by extending the external render engine API.
* Add support to Cycles to render AOVs in the 3d viewport.
* Use a drop down list for selecting AOVs in the AOV Output node.
* Give user feedback when multiple AOV output nodes with the same AOV name
exists in the same shader.
* Fix viewing single channel images in the image editor [T83314]
* Reduce viewport render time by only render needed draw passes. [T83316]
Reviewed By: Brecht van Lommel, Clément Foucault
Differential Revision: https://developer.blender.org/D7010
HDRI preview should have resolution dependent on dpi, viewport scale and HDRI gizmo size.
This patch uses a LOD to render a more round sphere.
Reviewed By: Jeroen Bakker
Differential Revision: https://developer.blender.org/D9382
This is caused by the TAA being reset after the init phase, leading to
1 sample being kept as valid when it is clearly not.
To fix this, we run the lookdev validation before TAA init.
Reviewed By: Jeroen Bakker
Differential Revision: https://developer.blender.org/D9452
This patch helps the case of intricate reflections where the
ray does not travel far before intersecting the geometry.
In these cases there could be false negative exclusion of the ray
caused by the backface rejection threshold.
The artifact manifested as lines of different values caused by faillure to
trace the depth buffer correctly.
Adding a ad-hoc value to the step size to mitigate the issue.
This patch fix most self intersection comming from reflection rays.
We regenerate the ray if it goes below the shading normal (should be the
geometric normal but we have no access to it here).
Also add the same precision based bias we use for contact shadows.
This fix T81105 Eevee SSR quality regression in 2.91 alpha
Corrects incorrect usages of the word 'loose' when 'lose' was required.
Differential Revision: https://developer.blender.org/D9243
Reviewed by Campbell Barton
Corrects incorrect usage of contraction for 'it is', when possessive 'its' was required.
Differential Revision: https://developer.blender.org/D9250
Reviewed by Campbell Barton
Regular rendering uses a custom blend mode, but render passes renders to
2 separate textures. This wasn't configured correctly inside the
fragment shaders. This patch adds a switch to configure the fragment
shader with the correct attachments.
Backport to Blender 2.83.
Reviewed By: Clément Foucault
Differential Revision: https://developer.blender.org/D9038
Based on http://jcgt.org/published/0008/01/03/
This is a simple trick that does *not* have a huge performance impact but
does work pretty well. It just modifies the Fresnel term to account for
the multibounce energy loss (coloration).
However this makes the shader variations count double. To avoid this we
use a uniform and pass the multiscatter use flag inside the sign of f90.
This is a bit hacky but avoids many code duplication.
This uses the simplification proposed by McAuley in
A Journey Through Implementing Multiscattering BRDFs and Area Lights
This does not handle area light differently than the IBL case but that's
already an issue in current implementation.
This is related to T68460.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D8912
This adds an option for the HDRI rotation to follow the view rotation.
When this option is enabled, this allows EEVEE materials to be used as
matcaps for sculpting and painting.
This has an extra performance cost when orbiting around the model as the
lookdev cache needs to be recalculated, but in my test it is barely
noticeable.
Reviewed By: fclem
Differential Revision: https://developer.blender.org/D8566
This wraps the functionality used to speedup EEVEE volumetrics.
This touches the rendering code of EEVEE as it should fix a mis-usage of
the GL barrier. The barrier changed type and location, removing an
unused barrier.
This prevents Blender from crashing when switching
to rendered view and the grid_data is NULL in the
lightcache (due to possible corruption), by switching
to the fallback lightcache. The fix extends the solution
for possible corruption in the cube_data as well.
Fix T79737
Reviewed By: fclem
Differential Revision: https://developer.blender.org/D8835
