class MAGES::MeshDeformations::SceneGraph::TearActionGhostMath¶

Overview¶

Pure, side-effect-free helpers backing the Tear Action ghost effect. Extracted from TearActionGhostEffectImplementor and TearActionGhostMarker so the centroid, disc-geometry, and cut-detection logic can be unit-tested without a live scene, camera, or simulation mesh. Mirrors the role of CutActionVolumeSelectionMath. More…

class TearActionGhostMath
{
public:
    // methods

    static bool GroupCenter(
        IReadOnlyList positions,
        IReadOnlyList indices,
        out float3 center
    );

    static void BuildCircleMesh(
        int segments,
        float radius,
        out Vector3[] vertices,
        out int[] triangles,
        out Vector3[] normals
    );

    static bool AnyConstraintDisabled(
        IReadOnlyList enabledStates,
        IReadOnlyList indices
    );

    static bool IsConstraintDisabled(
        int constraintIndex,
        int constraintCount,
        System.Func isDisabled
    );
};

Detailed Documentation¶

Methods¶

static bool GroupCenter(
    IReadOnlyList positions,
    IReadOnlyList indices,
    out float3 center
)

Returns the average of the positions referenced by indices.

Parameters:

positions	Particle positions, indexed by the values in indices.
indices	The positions to average. Indices outside positions are ignored.
center	The averaged centre, or float3.zero when nothing was averaged.

Returns:

true when at least one in-range position contributed.

static void BuildCircleMesh(
    int segments,
    float radius,
    out Vector3[] vertices,
    out int[] triangles,
    out Vector3[] normals
)

Builds a flat, camera-facing disc as a triangle fan in the XY plane (z = 0), facing +Z.

Parameters:

segments	The number of fan triangles around the rim. Clamped to a minimum of 3.
radius	The disc radius.
vertices	The resulting vertices: index 0 is the centre, indices 1.. segments are the rim. Length is `segments + 1`.
triangles	The triangle index buffer. Length is `segments * 3`.
normals	Per-vertex normals, all pointing +Z. Length matches vertices.

static bool AnyConstraintDisabled(
    IReadOnlyList enabledStates,
    IReadOnlyList indices
)

Returns true when at least one of indices is disabled (its enabledStates entry is false). Indices outside enabledStates are ignored rather than throwing.

Parameters:

enabledStates	Per-constraint enabled flags, indexed by volume-constraint index.
indices	The volume-constraint indices to inspect.

Returns:

true if any observed, in-range constraint is disabled.

static bool IsConstraintDisabled(
    int constraintIndex,
    int constraintCount,
    System.Func isDisabled
)

Returns true only when constraintIndex is in range (0 <= index < *constraintCount*) and isDisabled reports it disabled. An out-of-range index returns false. Mirrors the closure pattern of TearActionData.AreAllConstraintsDestroyed, sidestepping the NativeArray<bool> vs IReadOnlyList<bool> mismatch between the runtime enabled buffer and a plain list.

Parameters:

constraintIndex	The single volume-constraint index to inspect.
constraintCount	The number of constraints in the runtime buffer.
isDisabled	Reports whether the constraint at a given index is disabled.

Returns:

true when the in-range constraint is disabled.