Struct MeshInstance 

#[repr(C)]
pub struct MeshInstance {
    pub model: [[f32; 4]; 3],
    pub base_color: CompressedColor,
    pub joints_base: u32,
    pub metadata_index: u32,
    pub cutoff: f32,
    pub morph_base: u32,
    pub hull_width: f32,
}

One per-instance record: the affine model matrix, base color, pose bases, metadata index, alpha cutoff and inverted-hull width the built-in pipeline reads from its per-instance vertex buffer.

This is the vertex stream of lit.wesl’s instance slot, so upload a &[MeshInstance] as that slot’s buffer. The matrix is packed as three columns with each column’s .w holding the matching translation component, which is why it is stored as columns rather than a [glam::Mat4]: the shader transforms a point with three dot products and never treats it as a matrix.

Self::joints_base and Self::morph_base address the frame’s shared pose arrays, which is what lets two instances of one mesh deform differently: the joints and morph weights a draw deforms by are per-instance state, so they cannot live in the mesh’s own bind group. Skinning and morphing are independent, so the two bases are separate fields rather than the lanes of one vector — a variant that only skins reads no weight base.

Vertex attributes are addressed by the explicit offsets of crate::pipeline::LitVariant::vertex_buffer_layouts, not by WGSL shader-layout rules, so this type makes no const_shader_layout claim; that the offsets line up is asserted by a test instead.

The record is tightly packed — the sum of its vertex formats is its size — which is why the columns are [f32; 4] rather than [glam::Vec4]: a Vec4 is sixteen-byte aligned, which would round the record up and leave trailing padding the layout would have to account for.

Fields

model: [[f32; 4]; 3]

Affine model matrix columns, translation in each .w lane.

base_color: CompressedColor

Linear RGBA base color, Unorm8x4.

joints_base: u32

This instance’s first joint matrix in the frame’s shared joint array.

metadata_index: u32

Index of the mesh’s entry in the frame’s metadata array, which carries its decode parameters and its draw addressing.

The index is a property of the mesh rather than of the instance, but it rides the instance stream because that is what a draw can reach without a bind group of its own. Every instance of one mesh carries the same index.

cutoff: f32

Alpha below which a cut-off variant discards the fragment.

Zero for an instance that cuts nothing off, which no alpha falls below.

morph_base: u32

This instance’s first morph weight in the frame’s shared weight array.

hull_width: f32

How far this instance’s vertices are pushed out along their normals, in world units.

Zero for an instance that draws the mesh as itself, which is every instance that is not an inverted hull. The width is per-instance rather than a uniform because one mesh drawn twice — once as itself, once as the shell behind it — needs two widths from one pipeline, and because two shells of one mesh may be drawn at different thicknesses.

Implementations

impl MeshInstance

pub fn new(world_from_local: Affine3A, base_color: Vec4) -> Self

Build an instance from a world transform and a linear RGBA base color.

The color is quantized to the Unorm8x4 the instance stream carries, so a component outside 0..=1 saturates rather than wrapping. The instance reads no pose data, no metadata, no alpha cutoff and expands by no hull; point it at them with the with_* setters.

pub fn translation(&self) -> Vec3

The world-space translation this instance places its mesh at.

The model matrix stores it in the .w lane of each column, so this is how a caller reads it back out.

pub fn with_joints_base(self, joints_base: u32) -> Self

Point this instance at the joint matrices starting at joints_base in the frame’s shared joint array.

pub fn with_morph_base(self, morph_base: u32) -> Self

Point this instance at the morph weights starting at morph_base in the frame’s shared weight array.

pub fn with_metadata_index(self, metadata_index: u32) -> Self

Point this instance at the mesh metadata entry at metadata_index.

pub fn with_cutoff(self, cutoff: f32) -> Self

Discard this instance’s fragments below the alpha cutoff.

pub fn with_hull_width(self, hull_width: f32) -> Self

Push this instance’s vertices out along their normals by hull_width.

Trait Implementations

impl Clone for MeshInstance

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for MeshInstance

impl Debug for MeshInstance

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for MeshInstance

fn default() -> Self

Identity transform and opaque white.

impl FromBytes for MeshInstance

where [[f32; 4]; 3]: FromBytes, CompressedColor: FromBytes, u32: FromBytes, f32: FromBytes,

fn ref_from_bytes( source: &[u8], ) -> Result<&Self, ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, !>>

where Self: KnownLayout + Immutable,

Interprets the given source as a &Self.

fn ref_from_prefix( source: &[u8], ) -> Result<(&Self, &[u8]), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, !>>

where Self: KnownLayout + Immutable,

Interprets the prefix of the given source as a &Self without copying.

fn ref_from_suffix( source: &[u8], ) -> Result<(&[u8], &Self), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, !>>

where Self: Immutable + KnownLayout,

Interprets the suffix of the given bytes as a &Self.

fn mut_from_bytes( source: &mut [u8], ) -> Result<&mut Self, ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, !>>

where Self: IntoBytes + KnownLayout,

Interprets the given source as a &mut Self.

fn mut_from_prefix( source: &mut [u8], ) -> Result<(&mut Self, &mut [u8]), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, !>>

where Self: IntoBytes + KnownLayout,

Interprets the prefix of the given source as a &mut Self without copying.

fn mut_from_suffix( source: &mut [u8], ) -> Result<(&mut [u8], &mut Self), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, !>>

where Self: IntoBytes + KnownLayout,

Interprets the suffix of the given source as a &mut Self without copying.

fn ref_from_bytes_with_elems( source: &[u8], count: usize, ) -> Result<&Self, ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, !>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Interprets the given source as a &Self with a DST length equal to count.

fn ref_from_prefix_with_elems( source: &[u8], count: usize, ) -> Result<(&Self, &[u8]), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, !>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Interprets the prefix of the given source as a DST &Self with length equal to count.

fn ref_from_suffix_with_elems( source: &[u8], count: usize, ) -> Result<(&[u8], &Self), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, !>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Interprets the suffix of the given source as a DST &Self with length equal to count.

fn mut_from_bytes_with_elems( source: &mut [u8], count: usize, ) -> Result<&mut Self, ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, !>>

where Self: IntoBytes + KnownLayout<PointerMetadata = usize> + Immutable,

Interprets the given source as a &mut Self with a DST length equal to count.

fn mut_from_prefix_with_elems( source: &mut [u8], count: usize, ) -> Result<(&mut Self, &mut [u8]), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, !>>

where Self: IntoBytes + KnownLayout<PointerMetadata = usize>,

Interprets the prefix of the given source as a &mut Self with DST length equal to count.

fn mut_from_suffix_with_elems( source: &mut [u8], count: usize, ) -> Result<(&mut [u8], &mut Self), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, !>>

where Self: IntoBytes + KnownLayout<PointerMetadata = usize>,

Interprets the suffix of the given source as a &mut Self with DST length equal to count.

fn read_from_bytes(source: &[u8]) -> Result<Self, SizeError<&[u8], Self>>

where Self: Sized,

Reads a copy of Self from the given source.

fn read_from_prefix( source: &[u8], ) -> Result<(Self, &[u8]), SizeError<&[u8], Self>>

where Self: Sized,

Reads a copy of Self from the prefix of the given source.

fn read_from_suffix( source: &[u8], ) -> Result<(&[u8], Self), SizeError<&[u8], Self>>

where Self: Sized,

Reads a copy of Self from the suffix of the given source.

fn read_from_io<R>(src: R) -> Result<Self, Error>

where Self: Sized, R: Read,

Available on crate feature std only.

Reads a copy of self from an io::Read.

impl FromZeros for MeshInstance

where [[f32; 4]; 3]: FromZeros, CompressedColor: FromZeros, u32: FromZeros, f32: FromZeros,

fn zero(&mut self)

Overwrites self with zeros.

fn new_zeroed() -> Self

where Self: Sized,

Creates an instance of Self from zeroed bytes.

fn new_box_zeroed() -> Result<Box<Self>, AllocError>

where Self: Sized,

Available on crate features alloc only.

Creates a Box<Self> from zeroed bytes.

fn new_box_zeroed_with_elems(count: usize) -> Result<Box<Self>, AllocError>

where Self: KnownLayout<PointerMetadata = usize>,

Available on crate feature alloc only.

Creates a Box<[Self]> (a boxed slice) from zeroed bytes.

fn new_vec_zeroed(len: usize) -> Result<Vec<Self>, AllocError>

where Self: Sized,

Available on crate feature alloc only.

Creates a Vec<Self> from zeroed bytes.

fn extend_vec_zeroed( v: &mut Vec<Self>, additional: usize, ) -> Result<(), AllocError>

where Self: Sized,

Available on crate feature alloc and non-no_zerocopy_panic_in_const_and_vec_try_reserve_1_57_0 only.

Extends a Vec<Self> by pushing additional new items onto the end of the vector. The new items are initialized with zeros.

fn insert_vec_zeroed( v: &mut Vec<Self>, position: usize, additional: usize, ) -> Result<(), AllocError>

where Self: Sized,

Available on crate feature alloc and non-no_zerocopy_panic_in_const_and_vec_try_reserve_1_57_0 only.

Inserts additional new items into Vec<Self> at position. The new items are initialized with zeros.

impl Immutable for MeshInstance

where [[f32; 4]; 3]: Immutable, CompressedColor: Immutable, u32: Immutable, f32: Immutable,

impl IntoBytes for MeshInstance

where [[f32; 4]; 3]: IntoBytes, CompressedColor: IntoBytes, u32: IntoBytes, f32: IntoBytes, (): PaddingFree<Self, { _ }>,

fn as_bytes(&self) -> &[u8]

where Self: Immutable,

Gets the bytes of this value.

fn as_mut_bytes(&mut self) -> &mut [u8]

where Self: FromBytes,

Gets the bytes of this value mutably.

fn write_to(&self, dst: &mut [u8]) -> Result<(), SizeError<&Self, &mut [u8]>>

where Self: Immutable,

Writes a copy of self to dst.

fn write_to_prefix( &self, dst: &mut [u8], ) -> Result<(), SizeError<&Self, &mut [u8]>>

where Self: Immutable,

Writes a copy of self to the prefix of dst.

fn write_to_suffix( &self, dst: &mut [u8], ) -> Result<(), SizeError<&Self, &mut [u8]>>

where Self: Immutable,

Writes a copy of self to the suffix of dst.

fn write_to_io<W>(&self, dst: W) -> Result<(), Error>

where Self: Immutable, W: Write,

Available on crate feature std only.

Writes a copy of self to an io::Write.

impl KnownLayout for MeshInstance

where f32: KnownLayout,

type PointerMetadata = <f32 as KnownLayout>::PointerMetadata

The type of metadata stored in a pointer to Self.

fn size_for_metadata(meta: Self::PointerMetadata) -> Option<usize>

Computes the size of an object of type Self with the given pointer metadata.

impl PartialEq for MeshInstance

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for MeshInstance

impl TryFromBytes for MeshInstance

where [[f32; 4]; 3]: TryFromBytes, CompressedColor: TryFromBytes, u32: TryFromBytes, f32: TryFromBytes,

fn try_ref_from_bytes( source: &[u8], ) -> Result<&Self, ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout + Immutable,

Attempts to interpret the given source as a &Self.

fn try_ref_from_prefix( source: &[u8], ) -> Result<(&Self, &[u8]), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout + Immutable,

Attempts to interpret the prefix of the given source as a &Self.

fn try_ref_from_suffix( source: &[u8], ) -> Result<(&[u8], &Self), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout + Immutable,

Attempts to interpret the suffix of the given source as a &Self.

fn try_mut_from_bytes( bytes: &mut [u8], ) -> Result<&mut Self, ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout + IntoBytes,

Attempts to interpret the given source as a &mut Self without copying.

fn try_mut_from_prefix( source: &mut [u8], ) -> Result<(&mut Self, &mut [u8]), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout + IntoBytes,

Attempts to interpret the prefix of the given source as a &mut Self.

fn try_mut_from_suffix( source: &mut [u8], ) -> Result<(&mut [u8], &mut Self), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout + IntoBytes,

Attempts to interpret the suffix of the given source as a &mut Self.

fn try_ref_from_bytes_with_elems( source: &[u8], count: usize, ) -> Result<&Self, ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Attempts to interpret the given source as a &Self with a DST length equal to count.

fn try_ref_from_prefix_with_elems( source: &[u8], count: usize, ) -> Result<(&Self, &[u8]), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Attempts to interpret the prefix of the given source as a &Self with a DST length equal to count.

fn try_ref_from_suffix_with_elems( source: &[u8], count: usize, ) -> Result<(&[u8], &Self), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Attempts to interpret the suffix of the given source as a &Self with a DST length equal to count.

fn try_mut_from_bytes_with_elems( source: &mut [u8], count: usize, ) -> Result<&mut Self, ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + IntoBytes,

Attempts to interpret the given source as a &mut Self with a DST length equal to count.

fn try_mut_from_prefix_with_elems( source: &mut [u8], count: usize, ) -> Result<(&mut Self, &mut [u8]), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + IntoBytes,

Attempts to interpret the prefix of the given source as a &mut Self with a DST length equal to count.

fn try_mut_from_suffix_with_elems( source: &mut [u8], count: usize, ) -> Result<(&mut [u8], &mut Self), ConvertError<AlignmentError<&mut [u8], Self>, SizeError<&mut [u8], Self>, ValidityError<&mut [u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + IntoBytes,

Attempts to interpret the suffix of the given source as a &mut Self with a DST length equal to count.

fn try_read_from_bytes( source: &[u8], ) -> Result<Self, ConvertError<!, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: Sized,

Attempts to read the given source as a Self.

fn try_read_from_prefix( source: &[u8], ) -> Result<(Self, &[u8]), ConvertError<!, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: Sized,

Attempts to read a Self from the prefix of the given source.

fn try_read_from_suffix( source: &[u8], ) -> Result<(&[u8], Self), ConvertError<!, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: Sized,

Attempts to read a Self from the suffix of the given source.