{"record":{"id":"2f91a9b744a9a662","repo":"bevyengine/bevy","slug":"unable-to-generate-cubic-curve-at-least-one-set-o","errorCode":null,"errorMessage":"Unable to generate cubic curve: at least one set of control points is required","messagePattern":"Unable to generate cubic curve: at least one set of control points is required","errorType":"exception","errorClass":"CubicBezierError","httpStatus":null,"severity":"error","filePath":"crates/bevy_math/src/cubic_splines/mod.rs","lineNumber":92,"sourceCode":"    #[inline]\n    fn to_curve(&self) -> Result<CubicCurve<P>, Self::Error> {\n        let segments = self\n            .control_points\n            .iter()\n            .map(|p| CubicSegment::new_bezier(*p))\n            .collect_vec();\n\n        if segments.is_empty() {\n            Err(CubicBezierError)\n        } else {\n            Ok(CubicCurve { segments })\n        }\n    }\n}\n/// An error returned during cubic curve generation for cubic Bezier curves indicating that a\n/// segment of control points was not present.\n#[derive(Clone, Debug, Error)]\n#[error(\"Unable to generate cubic curve: at least one set of control points is required\")]\npub struct CubicBezierError;\n\n/// A spline interpolated continuously between the nearest two control points, with the position and\n/// velocity of the curve specified at both control points. This curve passes through all control\n/// points, with the specified velocity which includes direction and parametric speed.\n///\n/// Useful for smooth interpolation when you know the position and velocity at two points in time,\n/// such as network prediction.\n///\n/// ### Interpolation\n///\n/// The curve passes through every control point.\n///\n/// ### Tangency\n///\n/// Tangents are explicitly defined at each control point.\n///\n/// ### Continuity","sourceCodeStart":74,"sourceCodeEnd":110,"githubUrl":"https://github.com/bevyengine/bevy/blob/396ca727080776bd313bb892423b7d94e03b81b4/crates/bevy_math/src/cubic_splines/mod.rs#L74-L110","documentation":"CubicBezier::to_curve() errors when the spline holds no control point sets: at least one [P; 4] is required to form a segment (crates/bevy_math/src/cubic_splines/mod.rs:75-87). CubicBezier::new collects an iterator of 4-point sets, so an empty iterator yields an empty spline that cannot produce a curve.","triggerScenarios":"CubicBezier::new(empty_iterator).to_curve(), or building the control point list at runtime where a filter or data pipeline removed all points.","commonSituations":"Procedurally generated paths that end up empty (no samples passed a filter); config-driven curves with missing data; entity-driven curves where the source collection was despawned.","solutions":["Ensure at least one set of four control points is provided before calling to_curve().","Validate control_points is non-empty at construction time and fail loudly with context.","Log the point count where curves are generated to catch upstream data loss early."],"exampleFix":"// before\nlet curve = CubicBezier::new(points).to_curve().unwrap(); // points empty -> error\n\n// after\nassert!(!points.is_empty(), \"curve needs control points\");\nlet curve = CubicBezier::new(points).to_curve()?;","handlingStrategy":"validation","validationCode":"use bevy_math::CubicBezier;\n\nfn build_curve<P: VectorSpace<Scalar = f32>>(points: Vec<[P; 4]>) -> Option<Result<CubicCurve<P>, CubicBezierError>> {\n    if points.is_empty() {\n        return None;\n    }\n    Some(CubicBezier::new(points).to_curve())\n}","typeGuard":null,"tryCatchPattern":"let curve = CubicBezier::new(points).to_curve();\nmatch curve {\n    Ok(c) => { /* sample c */ }\n    Err(CubicBezierError) => { /* skip: no control point sets were provided */ }\n}","preventionTips":["Assert non-empty control point sets where curves are authored.","Validate procedurally generated point sets before curve construction.","Log point counts at generation sites to catch emptied collections."],"tags":["bevy","math","spline","bezier","curve","validation"],"backgroundTag":"insufficient-control-points","analyzedSha":"396ca727080776bd313bb892423b7d94e03b81b4","analyzedAt":"2026-08-20T16:12:39.808Z","contentChangedAt":"2026-08-20T16:12:39.808Z","schemaVersion":2},"datasetVersion":"2026-09-09T06:17:21.866Z"}