局部射线求交：归一化方向为何会选错最近对象

using System.Numerics;

public readonly record struct LocalRay(Vector3 Origin, Vector3 Direction);
public static class RayQuery
{
    static bool Finite(Vector3 v) => float.IsFinite(v.X) &&
        float.IsFinite(v.Y) && float.IsFinite(v.Z);

    public static LocalRay ToLocal(Vector3 origin, Vector3 direction, Matrix4x4 world)
    {
        if (!Finite(origin) || !Finite(direction) ||
            Math.Abs(direction.LengthSquared() - 1) > 1e-5)
            throw new ArgumentException("World direction must be unit length");
        if (world.M14 != 0 || world.M24 != 0 || world.M34 != 0 || world.M44 != 1 ||
            !Matrix4x4.Invert(world, out var inverse))
            throw new ArgumentException("Invertible affine matrix required");
        var ray = new LocalRay(Vector3.Transform(origin, inverse),
            Vector3.TransformNormal(direction, inverse));
        if (!Finite(ray.Origin) || !Finite(ray.Direction) || ray.Direction == Vector3.Zero)
            throw new ArgumentException("Invalid transformed ray");
        return ray;
    }

    static double Dot(Vector3 a, Vector3 b) =>
        (double)a.X * b.X + (double)a.Y * b.Y + (double)a.Z * b.Z;

    public static double? HitUnitSphere(LocalRay ray, double maxDistance)
    {
        if (!Finite(ray.Origin) || !Finite(ray.Direction) ||
            ray.Direction == Vector3.Zero || !double.IsFinite(maxDistance) || maxDistance < 0)
            throw new ArgumentException("Finite ray and nonnegative range required");
        double a = Dot(ray.Direction, ray.Direction);
        double b = Dot(ray.Origin, ray.Direction);
        double c = Dot(ray.Origin, ray.Origin) - 1;
        double discriminant = b * b - a * c;
        if (discriminant < 0) return null;
        double q = -b - Math.CopySign(Math.Sqrt(discriminant), b);
        double t0 = q == 0 ? -b / a : q / a;
        double t1 = q == 0 ? t0 : c / q;
        if (t0 > t1) (t0, t1) = (t1, t0);
        double t = t0 >= 0 ? t0 : t1;
        return t >= 0 && t <= maxDistance ? t : null;
    }
}

cd "$PROBE_PROJECT"
dotnet build RayLab.csproj -c Release
dotnet run --project RayLab.csproj -c Release --no-build

passed=19 failed=0 skipped=0
samples=648 elapsed_ms=10.1026
correctA=8 correctB=5 wrongA=4
winner=B wrongWinner=A localDirectionA=0.5
build_exit=0 run_exit=0