Mathf.Floor

public static float Floor (float f);

説明

f 以下の最大の整数を返します。

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    void Example() {
        Debug.Log(Mathf.Floor(10.0F));
        Debug.Log(Mathf.Floor(10.2F));
        Debug.Log(Mathf.Floor(10.7F));
        Debug.Log(Mathf.Floor(-10.0F));
        Debug.Log(Mathf.Floor(-10.2F));
        Debug.Log(Mathf.Floor(-10.7F));
    }
}