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
This patch allows the user to type a property name into the
Attribute node, which will then output the value of the property
for each individual object, allowing to e.g. customize shaders
by object without duplicating the shader.
In order to make supporting this easier for Eevee, it is necessary
to explicitly choose whether the attribute is varying or uniform
via a dropdown option of the Attribute node. The dropdown also
allows choosing whether instancing should be taken into account.
The Cycles design treats all attributes as one common namespace,
so the Blender interface converts the enum to a name prefix that
can't be entered using keyboard.
In Eevee, the attributes are provided to the shader via a UBO indexed
with resource_id, similar to the existing Object Info data. Unlike it,
however, it is necessary to maintain a separate buffer for every
requested combination of attributes.
This is done using a hash table with the attribute set as the key,
as it is expected that technically different but similar materials
may use the same set of attributes. In addition, in order to minimize
wasted memory, a sparse UBO pool is implemented, so that chunks that
don't contain any data don't have to be allocated.
The back-end Cycles code is already refactored and committed by Brecht.
Differential Revision: https://developer.blender.org/D2057
Add a new Alpha socket to the Attribute node that outputs the
fourth component of the attribute. Currently the only such
attribute is vertex color, but there may be more in the future.
If the attribute has no alpha channel, the expected value is 1.
The Cycles code is already refactored and committed by Brecht.
Ref D2057
This follows the GPU module naming of other buffers.
We pass name to distinguish each GPUUniformBuf in debug mode.
Also remove DRW_uniform_buffer interface.
This bridge between the new sampler state support from GPUTexture and
draw material handling.
The Sampler State is just the one from the texture for now. No change in
logic.
Note this only changes cases where the variable was declared inside
the for loop. To handle it outside as well is a different challenge.
Differential Revision: https://developer.blender.org/D7320
Only the volume drawing part is really finished and exposed to the user. Hair
plugs into the existing hair rendering code and is fairly straightforward. The
pointcloud drawing is a hack using overlays rather than Eevee and workbench.
The most tricky part for volume rendering is the case where each volume grid
has a different transform, which requires an additional matrix in the shader
and non-trivial logic in Eevee volume drawing. In the common case were all the
transforms match we don't use the additional per-grid matrix in the shader.
Ref T73201, T68981
Differential Revision: https://developer.blender.org/D6955
This has no user visible impact yet since smoke volumes only support a fixed
set of attributes, but will become important with the new volume object.
For GPU shader compilation, volume grids are now handled separately from
image textures. They are somewhere between a vertex attribute and an image
texture, basically an attribute that is stored as a texture.
Differential Revision: https://developer.blender.org/D6952
This further separates requested attributes and textures from the actual
node graph, that can be retained after the graph has been compiled and
freed. It makes it easier to add volume grids as a native concept, which
sits somewhere between an attribute and a texture.
It also adds explicit link types for UDIM tile mapping, rather than
relying on fairly hidden logic.
