DrawRendererBounds.cs

using UnityEngine;

// draws mesh renderer bounding box using Debug.Drawline
namespace UnityLibrary
{
    public class DrawRendererBounds : MonoBehaviour
    {
        MeshRenderer meshRenderer;

        void Awake()
        {
            meshRenderer = GetComponent<MeshRenderer>();
        }


        void Update()
        {
            var b = meshRenderer.bounds;

            // bottom
            var p1 = new Vector3(b.min.x, b.min.y, b.min.z);
            var p2 = new Vector3(b.max.x, b.min.y, b.min.z);
            var p3 = new Vector3(b.max.x, b.min.y, b.max.z);
            var p4 = new Vector3(b.min.x, b.min.y, b.max.z);

            Debug.DrawLine(p1, p2, Color.blue);
            Debug.DrawLine(p2, p3, Color.red);
            Debug.DrawLine(p3, p4, Color.yellow);
            Debug.DrawLine(p4, p1, Color.magenta);

            // top
            var p5 = new Vector3(b.min.x, b.max.y, b.min.z);
            var p6 = new Vector3(b.max.x, b.max.y, b.min.z);
            var p7 = new Vector3(b.max.x, b.max.y, b.max.z);
            var p8 = new Vector3(b.min.x, b.max.y, b.max.z);

            Debug.DrawLine(p5, p6, Color.blue);
            Debug.DrawLine(p6, p7, Color.red);
            Debug.DrawLine(p7, p8, Color.yellow);
            Debug.DrawLine(p8, p5, Color.magenta);

            // sides
            Debug.DrawLine(p1, p5, Color.white);
            Debug.DrawLine(p2, p6, Color.gray);
            Debug.DrawLine(p3, p7, Color.green);
            Debug.DrawLine(p4, p8, Color.cyan);
        }
    }
}