GizmoUtils.cs

using UnityEngine;

public static class GizmoUtils
{
    public static void DrawCircle(Vector3 pos, Vector3 forward, float radius)
    {
#if UNITY_EDITOR
        UnityEditor.Handles.color = Gizmos.color;
        UnityEditor.Handles.CircleHandleCap(
            -1, pos, Quaternion.LookRotation(forward), radius, EventType.Repaint);
#endif
    }

    public static void DrawLattice(Vector3 point, Vector3Int dimension)
    {
#if UNITY_EDITOR
        for (int y = 0; y < dimension.y + 1; y++)
        {
            for (int x = 0; x < dimension.x + 1; x++)
            {
                Gizmos.DrawLine(
                    point + new Vector3(x, y, 0),
                    point + new Vector3(x, y, dimension.z));
            }

            for (int z = 0; z < dimension.z + 1; z++)
            {
                Gizmos.DrawLine(
                    point + new Vector3(0, y, z),
                    point + new Vector3(dimension.x, y, z));
            }
        }

        for (int x = 0; x < dimension.x + 1; x++)
        {
            for (int z = 0; z < dimension.z + 1; z++)
            {
                Gizmos.DrawLine(
                    point + new Vector3(x, 0, z),
                    point + new Vector3(x, dimension.y, z));
            }
        }
#endif
    }

    public static void DrawLattice(Transform relativeTo, Vector3 point, Vector3Int dimension)
    {
#if UNITY_EDITOR
        point -= relativeTo.position;

        for (int y = 0; y < dimension.y + 1; y++)
        {
            for (int x = 0; x < dimension.x + 1; x++)
            {
                Gizmos.DrawLine(
                    point + relativeTo.TransformPoint(new Vector3(x, y, 0)),
                    point + relativeTo.TransformPoint(new Vector3(x, y, dimension.z)));
            }

            for (int z = 0; z < dimension.z + 1; z++)
            {
                Gizmos.DrawLine(
                    point + relativeTo.TransformPoint(new Vector3(0, y, z)),
                    point + relativeTo.TransformPoint(new Vector3(dimension.x, y, z)));
            }
        }

        for (int x = 0; x < dimension.x + 1; x++)
        {
            for (int z = 0; z < dimension.z + 1; z++)
            {
                Gizmos.DrawLine(
                    point + relativeTo.TransformPoint(new Vector3(x, 0, z)),
                    point + relativeTo.TransformPoint(new Vector3(x, dimension.y, z)));
            }
        }
#endif
    }
}