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
As proposed in T74432 and already implemented in several commits,
"region" is the preferred name for `ARegion` variables, rather than
any variant of "ar". This commit changes a few "ar" variables that have
popped up over time and also adjusted names of variants like "arnew".
Selecting an object by clicking on its instances only worked,
when the object itself is visible. However, it is possible to hide
the object and still keep the instances visible.
The solution is to give every object the correct `select_id` in the
depsgraph object iterator right before rendering.
Reviewers: fclem, brecht
Differential Revision: https://developer.blender.org/D9640
This change will use the image engine to draw the backdrop of the compositor. With this patch the alpha blending will be done in Linear Scene Reference space and shows pure emissive colors.
See differential for an example image.
**Technical changes**
As only the backdrop drawing is done using the draw manager there are some technical changes.
1. The overlay buffer is partly drawn outside the draw manager. When drawing the backdrop image the overlay buffer needs to be masked to simulate premultiplied alpha under.
2. The backdrop of the node editor is done in region pixel space. A `DRWView` is constructed with this space.
3. UDIM textures uses world position to generate the UV coordinates. This has been implemented more strict by the `IMAGE_DRAW_FLAG_USE_WORLD_POS`. When the flag isn't used the local coordinates are used to generate the UV coordinates what is image space.
4. The draw manager now checks the actual `eSpaceType` of the space data to use different code paths. In the future the movie clip editor will be added.
NOTE: The preview images in nodes are drawn in display space and cannot show pure emissive colors. As preview images are used on more locations it is best to fix this in a separate patch.
Reviewed By: Clément Foucault
Differential Revision: https://developer.blender.org/D9451
When lowering the wireframe opacity with sculpt overlays enabled, the
wireframe overlay was creating white artifacts along the edges.
Reviewed By: fclem
Differential Revision: https://developer.blender.org/D9607
Active tile could be NULL when it was on the second tile before
switching back and forth between the Image/UDIM.
In the future we might also check that the active_tile_index is always
valid.
The root cause of this bug is that the function that updates the PBVH
normals is drw_sculpt_generate_calls. As now both the overlays and
mesh can be drawn without using pbvh drawing, the normals were not
updating. This patch forces a normals updates also in the no PBVH
drawing code path of the overlays. This was affecting both shading and
sculpt surface sampling in both flat and smooth shading modes.
Having the sculpt normals being updated by the drawing code is a wrong
design which also causes other issues like:
Brushes that sample the surface and do multiple stroke steps between
redraws will sample invalid normals, creating artifacts during the
stroke clearly visible in some brushes.
Brushes that do not need to sample the surface update the normals on
each redraw. This affects performance a lot as in some cases, updating the
normals takes more time than doing the brush deformation. If flat shading
is being used, this is only necessary to do once after the stroke ends.
Reviewed By: fclem
Differential Revision: https://developer.blender.org/D9535
The clone tool in the image editor can show a second texture on top
of the image. This wasn't ported and now results into alpha and depth
issues. This fix adds the clone tool drawing to the overlay engine.
Reviewed By: Clément Foucault
Differential Revision: https://developer.blender.org/D9352
This was introduced by rBdb7d8281c5a2.
The color needs to be premultiplied as there is no blend mode and
the output color is replacing the framebuffer color & alpha.
Differential Revision: https://developer.blender.org/D8660
This patch is the result of the GSoC 2020 "Editing Grease Pencil Strokes
Using Curves" project. It adds a submode to greasepencil edit mode that
allows for the transformation of greasepencil strokes using bezier
curves. More information about the project can be found
here: https://wiki.blender.org/wiki/User:Filedescriptor/GSoC_2020.
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 patch adds an opacity slider to the wireframe overlay. The previous
wireframe in dense geometry scenes could be too dark and sometimes the
user just wants an impression of the geometry during modelling.
Reviewed By: Jeroen Bakker
Differential Revision: https://developer.blender.org/D7622
Perform grease pencil rendering delayed in this case, as there are no render
buffers available for compositing. This keeps memory usage lower, but does
involve multiple depsgraph evaluation. This seems in line with the intent of
the save buffers feature, to use minimal memory.
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 will apply the view transform when a movie clip is used as
camera background image. It does this by rendering the image in the
color buffer when it needs the view transform. For other images it uses
the overlay buffer.
Reviewed By: Clément Foucault
Differential Revision: https://developer.blender.org/D7067
Issue was that the `tris_per_mat` are not created when the first batch is drawn
during select operator and then is not created when needed by the workbench pass
since they are not tracked by mesh_buffer_cache_create_requested.
This change will create the `tris_per_mat` just in case they are needed later.
Solution by Clément Foucault
Differential Revision: https://developer.blender.org/D9430
