When using cycles in the viewport there it uses render threads and
workers to update the viewport. All threads can record commands to the
queue and needs to be synchronized. This didn't happen leading to
incorrect renders.
Detected when researching #128608
Pull Request: https://projects.blender.org/blender/blender/pulls/128975
This PR will share render graphs between all contexts that run in
the same thread. This allows the draw manager commands to be added
to the same render graph as the UI.
- Fixes debug groups hiearchy. Draw manager would restart a hierarchy as
it wasn't aware of the debug groups already added by the UI
- Removes cpu sync when switching between contexts.
In a future change this is needed to improve discarding resources.
Pull Request: https://projects.blender.org/blender/blender/pulls/124715
Adds debug print function to output a node with its inputs and outputs.
Also keep track of the name of the resource (only images) what will
be presented. Tracking of the resource name is only done in debug builds.
Pull Request: https://projects.blender.org/blender/blender/pulls/124033
Vulkan backend has recently switched to a render graph approach. Many
code was left so we could develop the render graph beside the previous
implementation. Last week we removed the switch. This PR will remove
most of the unused code. There might be some left and will be removed
when detected.
Pull Request: https://projects.blender.org/blender/blender/pulls/123422
This PR adds drawing support to the render graph. It adds support for
draw, indirect draw, indexed draw and indexed indirect draw.
Draw commands can only be executed within a rendering scope. Data
transfer commands and dispatch commands cannot be executed within a
rendering scope. Blender can still send in commands in any order and
the render graph needs to find out the best order to minimize context
switches (rendering/begin/end). This is the responsibility of the
scheduler.
The scheduler will push data transfer and dispatch commands outside the
rendering scope:
- data transfer and dispatch commands at the beginning are done before
the rendering begin.
- data transfer and dispatch commands at the end are done after the
rendering end.
- data transfer and dispatches in between draw commands will be pushed
to the beginning if they are not yet being used.
- for all other data transfer and dispatch commands the rendering is
suspenderd and will be continued afterwards.
Within a rendering context it is not allowed to perform synchronization
commands. Any synchronization commands inside a rendering scope will be
performed before the rendering scope begins. Nodes are now organized
in groups to simplify the code around this area.
Pull Request: https://projects.blender.org/blender/blender/pulls/123168
This PR implements debug groups in the render graph. Each node contains
a reference to the debug group they belong to. During scheduling the
nodes can be reordered and the correct debug group needs to be
activated.
This is done by keeping track of the current debug group. When a
different debug group is needed, the needed ends/begins are added
to the command buffer.
This mechanism also cleans up debug groups that are not used at all
as they don't have any nodes associated to it.
Pull Request: https://projects.blender.org/blender/blender/pulls/122054
There was a memory leak in the render graph where nodes where freed,
but not the data it could keep. Detected during adding support for
compute shaders and running the draw tests.
Pull Request: https://projects.blender.org/blender/blender/pulls/120906
This PR implements render graph for VKTexture. During the
implementation some tweaks to the render graph was done
to support depth and stencil textures.
The render graph will record the image aspect being used
for each node. This will then be used to generate barriers
for the correct aspect.
Also fixes an issue that uploading of array textures didn't
allocate a large enough staging buffer.
Pull Request: https://projects.blender.org/blender/blender/pulls/120821
**Design Task**: blender/blender#118330
This PR adds the core of the render graph. The render graph isn't used.
Current implementation of the Vulkan Backend is slow by design. We
focused on stability, before performance. With the new introduced render
graph the focus will shift to performance and keep the stability at where
it is.
Some highlights:
- Every context will get its own render graph. (`VKRenderGraph`).
- Resources (and resource state tracking) is device specific (`VKResourceStateTracker`).
- No node reordering / sub graph execution has been implemented. Currently
All nodes in the graph is executed in the order they were added. (`VKScheduler`).
- The links inside the graph describe the resources the nodes read from (input links)
or writes to (output links)
- When resources are written to a resource stamp is incremented allowing keeping
track of which nodes needs which stamp of a resource.
- At each link the access information (how does the node accesses the resource)
and image layout (for image resources) are stored. This allows the render graph
to find out how a resource was used in the past and will be used in the future.
That is important to construct pipeline barriers that don't stall the whole GPU.
# Defined nodes
This implementation has nodes for:
- Blit image
- Clear color image
- Copy buffers to buffers
- Copy buffers to images
- Copy images to images
- Copy images to buffers
- Dispatch compute shader
- Fill buffers
- Synchronization
Each node has a node info, create info and data struct. The create info
contains all data to construct the node, including the links of the graph.
The data struct only contains the data stored inside the node. The node info
contains the node specific implementation.
> NOTE: Other nodes will be added after this PR lands to main.
# Resources
Before a render graph can be used, the resources should be registered
to `VKResourceStateTracker`. In the final implementation this will be owned by
the `VKDevice`. Registration of resources can be done by calling
`VKResources.add_buffer` or `VKResources.add_image`.
# Render graph
Nodes can be added to the render graph. When adding a node its read/
write dependencies are extracted and converted into links (`VKNodeInfo.
build_links`).
When the caller wants to have a resource up to date the functions
`VKRenderGraph.submit_for_read` or `VKRenderGraph.submit_for_present`
can be called.
These functions will select and order the nodes that are needed
and convert them to `vkCmd*` commands. These commands include pipeline
barrier and image layout transitions.
The `vkCmd` are recorded into a command buffer which is sent to the
device queue.
## Walking the graph
Walking the render graph isn't implemented yet. The idea is to have a
`Map<ResourceWithStamp, Vector<NodeHandle>> consumers` and
`Map<ResourceWithStamp, NodeHandle> producers`. These attributes can
be stored in the render graph and created when building the links, or
can be created inside the VKScheduler as a variable. The exact detail
which one would be better is unclear as there aren't any users yet. At
the moment the scheduler would need them we need to figure out the best
way to store and retrieve the consumers/producers.
# Unit tests
The render graph can be tested by enabling `WITH_GTEST` and use
`vk_render_graph` as a filter.
```
bin/tests/blender_test --gtest_filter="vk_render_graph*"
```
Pull Request: https://projects.blender.org/blender/blender/pulls/120427
