"Raycast Normals" was introduced in 4.4 dev and defaulted to "false".
The limited testing results at the time suggested that raycasting
generally reduces normal quality compared to native simplifier results,
at the same time increasing vertex memory and import time.
To play it safe, we introduced a setting that defaulted to false, with
the goal of removing it later in 4.4 development cycle if no regressions
are noticed. Since we already had three dev snapshots and no reports,
this change removes the setting and associated code.
"Normal Split Angle" was only used when raycast normals were enabled;
this change removes it from the settings, but keeps it in the script
binding for compatibility.
Existing meshes import exactly the same after this change (unless they
chose to override raycasting which would be surprising).
split_normals helper was only used in this code path and is also removed
for simplicity; it is unlikely that this code will be useful as is, as
it can only regenerate normals without fixing tangents or updating
positions.
The Godot-specific patch is just a single line now; removing this patch
will likely require adjusting Godot importer code to handle error limits
better.
This also adds new SIMPLIFY_ options; Godot is currently not using any
of these but might use SIMPLIFY_PRUNE and SIMPLIFY_SPARSE in the future.
optimize_vertex_cache_func assumes the input is a triangle mesh; when an
imported mesh contains points/lines/triangle strips, this code should be
disabled.
Previously, vertex cache optimization was ran for the LOD meshes, but
was never ran for the base mesh or for the shadow meshes, including
shadow LOD chain (shadow LOD chain would sometimes get implicitly
optimized for vertex cache as a byproduct of base LOD optimization, but
not always). This could significantly affect the rendering performance
of geometry heavy scenes, especially for depth or shadow passes where
the fragment load is light.
These properties look like they were intended to be internal but they were missing the `PROPERTY_USAGE_INTERNAL` flag.
- `PackedScene::_bundled`
- `PortableCompressedTexture2D::_data`
- `ImporterMesh::_data`
When UVs are mirrored in a mesh, collapsing vertices across the
mirroring seam can significantly reduce quality in a way that is not
apparent to the simplifier. Even if simplifier was given access to UV
data, the coordinates would need to be weighted very highly to prevent
these collapses, which would penalize overall quality of reasonable
models.
Normally, well behaved models with mirrored UVs have tangent data that
is correctly mirrored, which results in duplicate vertices along the
seam. The simplifier automatically recognizes that seam and preserves
its structure; typically models have few edge loops where UV winding is
flipped so this does not affect simplification quality much.
However, pre-processing for LOD data welded vertices when UVs and
normals were close, which welds these seams and breaks simplification,
creating triangles with distorted UVs.
We now take tangent frame sign into account when the input model has
tangent data, and only weld vertices when the sign is the same.
Normal raycaster makes LOD generation process >2x slower and often
generates normals that look significantly worse compared to what the
simplifier comes up with by default. This was likely different before
last meshoptimizer upgrade, as the attribute metric was not functioning
properly, but now it looks like it's doing more harm than good.
This change makes it disabled by default but keeps an easy option to
re-enable it per mesh using LOD parameters for now until we get more
confidence and can remove the code outright.
Because the long term plan would be to disable this feature entirely,
the scripting API isn't changed, and it's just off-by-default there with
no way to re-enable.
