What causes "Chunk width must be at least 1" in bevyengine/bevy?

Pass width >= 1 — for vector samples it is the vector dimension.

bevyengine/bevy · error · ChunkedUnevenCoreError

Chunk width must be at least 1

Error message

Chunk width must be at least 1

What it means

ChunkedUnevenCoreError::ZeroWidth is returned by ChunkedUnevenCore::new when `width` is 0. The width is the number of values per sample time (the chunk size); zero would mean samples carry no data, and it also makes the values-length check meaningless (any length matches 0 times n). new_width_inferred can hit it too when values is empty.

Source

Thrown at crates/bevy_math/src/curve/cores.rs:488

    ///
    /// # Invariants
    /// This must always have a length of at least 2, be sorted, and have no duplicated or
    /// non-finite times.
    pub times: Vec<f32>,

    /// The values that are used in sampling. Each width-worth of these correspond to a single sample.
    ///
    /// # Invariants
    /// The length of this vector must always be some fixed integer multiple of that of `times`.
    pub values: Vec<T>,
}

/// An error that indicates that a [`ChunkedUnevenCore`] could not be formed.
#[derive(Debug, Error)]
#[error("Could not create a ChunkedUnevenCore")]
pub enum ChunkedUnevenCoreError {
    /// The width of a `ChunkedUnevenCore` cannot be zero.
    #[error("Chunk width must be at least 1")]
    ZeroWidth,

    /// At least two sample times are necessary to interpolate in `ChunkedUnevenCore`.
    #[error(
        "Need at least two unique samples to create a ChunkedUnevenCore, but {samples} were provided"
    )]
    NotEnoughSamples {
        /// The number of samples that were provided.
        samples: usize,
    },

    /// The length of the value buffer is supposed to be the `width` times the number of samples.
    #[error("Expected {expected} total values based on width, but {actual} were provided")]
    MismatchedLengths {
        /// The expected length of the value buffer.
        expected: usize,
        /// The actual length of the value buffer.
        actual: usize,

View on GitHub (pinned to 396ca72708)

Solutions

Pass width >= 1 — for vector samples it is the vector dimension.
Fix the width computation: check `values.len()` against processed (filtered/deduped) times, not raw times, and guard the division.
If values is legitimately empty, skip curve construction entirely.

Example fix

// before
let width = values.len() / times.len(); // floors to 0 when len(times) > len(values)
let core = ChunkedUnevenCore::new(times, values, width)?; // ZeroWidth

// after
let width = sample_dim; // known vector dimension, e.g. Vec3 => 3
let core = ChunkedUnevenCore::new(times, values, width)?;

Defensive patterns

Strategy: validation

Validate before calling

assert!(width >= 1, "chunk width must be at least 1");
if width >= 1 {
    let core = ChunkedUnevenCore::new(times, values, width)?;
}

Try / catch

let core = match ChunkedUnevenCore::new(times, values, width) {
    Ok(core) => core,
    Err(ChunkedUnevenCoreError::ZeroWidth) => {
        ChunkedUnevenCore::new(times, values, 1)? // treat samples as scalars
    }
    Err(e) => return Err(e.into()),
};

Prevention

Take width from the sample type's dimension (Vec2 => 2, Vec3 => 3) instead of deriving it by division.
Guard any `values.len() / times.len()` computation against a zero result.
Reject empty values buffers at asset load before attempting construction.

When it happens

Trigger: ChunkedUnevenCore::new(times, values, 0) — width often computed as values.len() / times.len() with integer division that floors to 0; new_width_inferred with an empty values list.

Common situations: Dynamically computing width from data whose sizes are mismatched; template/generic code where the sample dimension type is empty; asset loaders receiving an empty channel buffer.

Related errors

AI-assisted analysis of bevyengine/bevy@396ca72708 (2026-08-20). Data as JSON: /api/errors/4f5805d30056833d. Report an issue: GitHub.