Implementation of the design task #142969.
This adds the following:
- Exact GPU interpolation of curves of all types.
- Radius attribute support.
- Cyclic curve support.
- Resolution attribute support.
- New Cylinder hair shape type.
What changed:
- EEVEE doesn't compute random normals for strand hairs anymore. These are considered legacy now.
- EEVEE now have an internal shadow bias to avoid self shadowing on hair.
- Workbench Curves Strip display option is no longer flat and has better shading.
- Legacy Hair particle system evaluates radius at control points before applying additional subdivision. This now matches Cycles.
- Color Attribute Node without a name do not fetch the active color attribute anymore. This now matches Cycles.
Notes:
- This is not 100% matching the CPU implementation for interpolation (see the epsilons in the tests).
- Legacy Hair Particle points is now stored in local space after interpolation.
The new cylinder shape allows for more correct hair shading in workbench and better intersection in EEVEE.
| | Strand | Strip | Cylinder |
| ---- | --- | --- | --- |
| Main |  |  | N/A |
| PR |  |  |  |
| | Strand | Strip | Cylinder |
| ---- | --- | --- | --- |
| Main |  | | N/A |
| PR | ||  |
Cyclic Curve, Mixed curve type, and proper radius support:
Test file for attribute lookup: [test_attribute_lookup.blend](/attachments/1d54dd06-379b-4480-a1c5-96adc1953f77)
Follow Up Tasks:
- Correct full tube segments orientation based on tangent and normal attributes
- Correct V resolution property per object
- More attribute type support (currently only color)
TODO:
- [x] Attribute Loading Changes
- [x] Generic Attributes
- [x] Length Attribute
- [x] Intercept Attribute
- [x] Original Coordinate Attribute
- [x] Cyclic Curves
- [x] Legacy Hair Particle conversion
- [x] Attribute Loading
- [x] Additional Subdivision
- [x] Move some function to generic headers (VertBuf, OffsetIndices)
- [x] Fix default UV/Color attribute assignment
Pull Request: https://projects.blender.org/blender/blender/pulls/143180
With 5.0 we start requiring this extension for GL and VK.
All of our target hardware supports it with up to date
drivers.
Some old drivers were disabling this extension because of
buggy behavior. We simply drop support for them in 5.0.
This allows us to remove a lot of code and the last
shader create info override done at startup. This will
unlock more refactoring of the shader create info into
static classes to reduce binary size and other benefits.
## TODO:
- [x] Remove checks for ARB_shader_draw_parameters
- [x] Remove checks for ARB_clip_control
- [x] Check for the extension on startup for OpenGL
- [x] Check for the extension on startup for Vulkan
- [x] ~~Add user facing popup message about minimum
requirements not being met.~~ Done using the same
popup as old hardware.
Pull Request: https://projects.blender.org/blender/blender/pulls/142334
This allows to store a number of vertex to draw
per batch without specifying any attribute.
This allows to create batches that are empty but
still holds the amount of geometry to produce.
Needed for new curve drawing #142969.
Pull Request: https://projects.blender.org/blender/blender/pulls/143052
This allows multiple threads to request different specializations without
locking usage of all specialized shaders program when a new specialization
is being compiled.
The specialization constants are bundled in a structure that is being
passed to the `Shader::bind()` method. The structure is owned by the
calling thread and only used by the `Shader::bind()`.
Only querying for the specialized shader (Map lookup) is locking the shader
usage.
The variant compilation is now also locking and ensured that
multiple thread trying to compile the same variant will never result
in race condition.
Note that this removes the `is_dirty` optimization. This can be added
back if this becomes a bottleneck in the future. Otherwise, the
performance impact is not noticeable.
Pull Request: https://projects.blender.org/blender/blender/pulls/136991
This port is not so straightforward.
This shader is used in different configurations and is
available to python bindings. So we need to keep
compatibility with different attributes configurations.
This is why attributes are loaded per component and a
uniform sets the length of the component.
Since this shader can be used from both the imm and batch
API, we need to inject some workarounds to bind the buffers
correctly.
The end result is still less versatile than the previous
metal workaround (i.e.: more attribute fetch mode supported),
but it is also way less code.
### Limitations:
The new shader has some limitation:
- Both `color` and `pos` attributes need to be `F32`.
- Each attribute needs to be 4byte aligned.
- Fetch type needs to be `GPU_FETCH_FLOAT`.
- Primitive type needs to be `GPU_PRIM_LINES`, `GPU_PRIM_LINE_STRIP` or `GPU_PRIM_LINE_LOOP`.
- If drawing using an index buffer, it must contain no primitive restart.
Rel #127493
Co-authored-by: Jeroen Bakker <jeroen@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/129315
This PR introduces the concept of primitive expansion draws.
This allows to create a drawcall that will generate N amount of new
primitive for an original primitive in a `gpu::Batch`. The intent is to
phase out the use of geometry shader for this purpose.
This adds a new `Frequency::GEOMETRY` only available for SSBOs.
The resources using this will be fed the current `gpu::Batch` VBOs
using name matching.
A dedicated slot is reserved for the index buffer, which has its own
internal lib to decode the index buffer content.
A new attribute lib is added to ease the loading of unaligned attribute.
This should be revisited and made obsolete once more refactor
lands.
It is similar to the Metal backend SSBO vertex fetch path but it is
defined on a different level. The main difference is that this PR is
backend independant and modify the draw module instead of the GPU
module. However, it doesn't cover all possible attribute conversion
cases. This will only be added if needed.
This system is less automatic than the Metal backend one and needs
more care to make sure the data matches what the shader expects.
The Metal system will be removed once all its usage have been
converted.
This PR only shows example usage for workbench shadows. Cleanup PRs
will follow this one.
Rel #105221
Pull Request: https://projects.blender.org/blender/blender/pulls/125782
Now that all relevant code is C++, the indirection from the C struct
`GPUVertBuf` to the C++ `blender::gpu::VertBuf` class just adds
complexity and necessitates a wrapper API, making more cleanups like
use of RAII or other C++ types more difficult.
This commit replaces the C wrapper structs with direct use of the
vertex and index buffer base classes. In C++ we can choose which parts
of a class are private, so we don't risk exposing too many
implementation details here.
Pull Request: https://projects.blender.org/blender/blender/pulls/119825
