ShowHoveredInfo.cs

using System.Linq;

namespace UnityEngine.ProBuilder.Debug
{
    /// <summary>Internal class.</summary>
    [RequireComponent(typeof(Collider))]
    public class ShowHoveredInfo : MonoBehaviour
    {
        Mesh m_Mesh;
        static Material m_Material;
        bool m_IsHovering;

#if UNITY_EDITOR
        [RuntimeInitializeOnLoadMethod]
        static void ResetStaticsOnLoad()
        {
            m_Material = null;
        }
#endif

        void Start()
        {
            if (m_Material == null)
                m_Material = new Material(Shader.Find("Unlit/Color"));
            Mesh original = GetComponent<MeshFilter>().sharedMesh;
            m_Mesh = new Mesh();
            m_Mesh.vertices = original.vertices;
            int[] tris = original.triangles;
            int[] lines = new int[tris.Length * 2];
            int index = 0;
            for (int i = 0; i < tris.Length; i += 3)
            {
                lines[index++] = tris[i];
                lines[index++] = tris[i + 1];
                lines[index++] = tris[i + 1];
                lines[index++] = tris[i + 2];
                lines[index++] = tris[i + 2];
                lines[index++] = tris[i];
            }

            m_Mesh.SetIndices(lines, MeshTopology.Lines, 0, false);
        }

        void OnMouseEnter()
        {
            m_IsHovering = true;
        }

        void OnMouseExit()
        {
            m_IsHovering = false;
        }

        void OnGUI()
        {
            if (!m_IsHovering)
                return;

            GUI.Label(
                new Rect(Input.mousePosition.x, Screen.height - Input.mousePosition.y, 600f, 900f),
                gameObject.name + "\n" + string.Join("\n",
                    GetComponents<Component>().Select(x => x.GetType().ToString()).ToArray()));
        }

        void OnRenderObject()
        {
            m_Material.SetPass(0);
            Graphics.DrawMeshNow(m_Mesh, transform.localToWorldMatrix, 0);
        }
    }
}