try
{
    var cam = UnityEngine.Camera.main;

    if (cam == null)
    {
        UnityEngine.Debug.LogError(
            "[GB] Main Camera not found");
    }
    else
    {
        // 立方体を生成
        var cube = UnityEngine.GameObject.CreatePrimitive(
            UnityEngine.PrimitiveType.Cube);

        cube.name = "GreenCube_Wall";

        // カメラを立方体の中心に配置
        cube.transform.position = cam.transform.position;
        cube.transform.rotation = UnityEngine.Quaternion.identity;

        // 立方体のサイズ
        float size = 10f;
        cube.transform.localScale =
            new UnityEngine.Vector3(size, size, size);

        // URP Litシェーダーを取得
        var shader = UnityEngine.Shader.Find(
            "Universal Render Pipeline/Lit");

        if (shader == null)
        {
            UnityEngine.Debug.LogError(
                "[GB] URP Lit shader not found");

            UnityEngine.Object.Destroy(cube);
        }
        else
        {
            var mat = new UnityEngine.Material(shader);

            // 緑色に設定
            mat.color = UnityEngine.Color.green;

            if (mat.HasProperty("_BaseColor"))
            {
                mat.SetColor(
                    "_BaseColor",
                    UnityEngine.Color.green);
            }

            // 裏面も描画して内側から見えるようにする
            if (mat.HasProperty("_Cull"))
            {
                mat.SetInt(
                    "_Cull",
                    (int)UnityEngine.Rendering.CullMode.Off);
            }

            mat.doubleSidedGI = true;

            var renderer =
                cube.GetComponent<UnityEngine.Renderer>();

            renderer.material = mat;
            renderer.enabled = true;

            // 当たり判定を削除
            var collider =
                cube.GetComponent<UnityEngine.Collider>();

            if (collider != null)
            {
                UnityEngine.Object.Destroy(collider);
            }

            UnityEngine.Debug.Log(
                "[GB] Green cube room created");
            UnityEngine.Debug.Log(
                "[GB] Position = " + cube.transform.position);
            UnityEngine.Debug.Log(
                "[GB] Scale = " + cube.transform.localScale);
            UnityEngine.Debug.Log(
                "[GB] Shader = " + mat.shader.name);
        }
    }
}
catch (System.Exception e)
{
    UnityEngine.Debug.LogError(
        "[GB] ERROR: " + e);
}