Struct MeshInstanceItem 

#[non_exhaustive]
pub struct MeshInstanceItem {
    pub mesh_id: MeshId,
    pub texture_id: Option<TextureId>,
    pub transforms: Vec<[[f32; 4]; 4]>,
    pub colours: Vec<[f32; 4]>,
    pub blend: SpriteBlend,
    pub settings: ItemSettings,
    pub lod_group: Option<LodGroupId>,
}

A host-built instanced draw of a single mesh at many per-instance transforms.

Use this for mesh-based particle effects (falling leaves, debris, alembic snippets, projectile clouds) where the simulation lives in the host and the renderer only needs to draw N copies of one mesh per frame in a single draw call. The list of instances is rebuilt every frame from the supplied transforms and colours vectors; nothing is retained between frames.

All instances in a batch share the same mesh_id, texture_id, and blend mode. To mix meshes or blend modes, submit multiple MeshInstanceItem entries on [SceneFrame::mesh_instances].

The fragment shader is the unlit instanced mesh shader (the same shader backing the scene-graph instanced path). Mesh particles do not receive shadows or lighting; they are tinted by colours and optionally sampled from texture_id.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

mesh_id: MeshId

Mesh handle returned by DeviceResources::upload_mesh_data.

texture_id: Option<TextureId>

Optional albedo texture handle. None renders flat-shaded with the per-instance colours alone.

transforms: Vec<[[f32; 4]; 4]>

Per-instance world-space TRS matrices. Length defines the instance count.

colours: Vec<[f32; 4]>

Per-instance RGBA tints. If shorter than transforms, missing entries fall back to opaque white.

blend: SpriteBlend

GPU blend state for this batch. Reuses SpriteBlend from the sprite path so both particle systems share one enum.

settings: ItemSettings

Per-item render settings (visibility, pick identity, selection state).

lod_group: Option<LodGroupId>

LOD group to draw these instances from. None means draw mesh_id directly for every instance.

When set, the renderer measures each instance’s on-screen size and groups the instances by level, drawing each level’s subset with its own mesh. So near instances in the batch draw the full mesh while far ones drop to a cheaper one, all from a single submitted item. mesh_id is ignored. Set pick_id for the per-instance level to use hysteresis across frames.

Trait Implementations

impl Clone for MeshInstanceItem

fn clone(&self) -> MeshInstanceItem

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Default for MeshInstanceItem

fn default() -> Self

Returns the “default value” for a type.