This adds a function that can turn an existing `bNodeTree` into an inlined one.
The new node tree has all node groups, repeat zones, closures and bundles
inlined. So it's just a flat tree that ideally can be consumed easily by render
engines. As part of the process, it also does constant folding.
The goal is to support more advanced features from geometry nodes (repeat zones,
etc.) in shader nodes which the evaluator is more limited because it has to be
able to run on the GPU. Creating an inlined `bNodeTree` is likely the most
direct way to get but may also be limiting in the future. Since this is a fairly
local change, it's likely still worth it to support these features in all render
engines without having to make their evaluators significantly more complex.
Some limitations apply here that do not apply in Geometry Nodes. For example,
the iterations count in a repeat zone has to be a constant after constant
folding.
There is also a `Test Inlining Shader Nodes` operator that creates the inlined
tree and creates a group node for it. This is just for testing purposes.
#145811 will make this functionality available to the Python API as well so that
external renderers can use it too.
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
Cleanup and simplification of GPUMaterial and GPUPass compilation.
See #133674 for details/goals.
- Remove the `draw_manage_shader` thread.
Deferred compilation is now handled by the gpu::ShaderCompiler
through the batch compilation API.
Batch management is handled by the `GPUPassCache`.
- Simplify `GPUMaterial` status tracking so it just queries the
`GPUPass` status.
- Split the `GPUPass` and the `GPUCodegen` code.
- Replaced the (broken) `GPU_material_recalc_flag_get` with the new
`GPU_pass_compilation_timestamp`.
- Add the `GPU_pass_cache_wait_for_all` and
`GPU_shader_batch_wait_for_all`, and remove the busy waits from
EEVEE.
- Remove many unused functions, properties, includes...
Pull Request: https://projects.blender.org/blender/blender/pulls/135637
This makes it possible to restore previous Blender 4.3 behavior of bump
mapping, where the large filter width was sometimes (ab)used to get a bevel
like effect on stepwise textures.
For bump from the displacement socket, filter width remains fixed at 0.1.
Ref #133991, #135841
Pull Request: https://projects.blender.org/blender/blender/pulls/136465
Attribute name could be a path built from multiple object/property names
while each of them can be 64 symbols long.
This was fixed by cff53fdb53, so Cycles
can handle this. But eevee need additional change.
Pull Request: https://projects.blender.org/blender/blender/pulls/131183
Request one separate compilation batch for each GPUPass so users can
get a better sense of the compilation progress, and to better distribute
texture loading over time.
Pull Request: https://projects.blender.org/blender/blender/pulls/125012
With the new closure approach, the code can be simplified and cleaned up quite
a bit.
This also removes four parameters, which is helpful for future additions (!123616)
since the parameter limit appears to be reached.
Pull Request: https://projects.blender.org/blender/blender/pulls/123643
The goal of this task is to remove noise in the most common material
layering configuration.
Subsequently, this also split the evaluation of different closure to
their own buffer to avoid discontinuity when denoising them.
This commit does a few things:
- [x] Removes use of global for closure random number.
- [x] Refactor the forward evaluation to be closure type agnostic.
- [x] Refactor the gbuffer lib to be closure type agnostic.
- [x] Reduces the number of picked closure to 3 maximum or less.
- [x] Use GPU_MATFLAG_COAT to tag the use of multiple usage of glossy BSDF.
- [x] Use two closure bin for Glossy when more than one.
- [x] Set closure bin per type for best noise level for most materials.
- [x] Change the gbuffer header to put the closure at their bin index.
- [x] Add a method to get a closure from the gbuffer from a specific bin.
- [x] Split lighting passes per Closure.
Pull Request: https://projects.blender.org/blender/blender/pulls/118079
The benefits are removing unnecessary reallocations of the string data
and unnecessary recalculations of the size, better type safety, and more
automatic memory management.
Pull Request: https://projects.blender.org/blender/blender/pulls/118045