Matrix4x4.determinant

説明

The determinant of the matrix. (Read Only)

You can not invert matrices with a determinant of zero.

using UnityEngine;

public class ExampleScript : MonoBehaviour
{
    void Update()
    {
        // create a transformation matrix with scale, zero position and no rotation
        var scale = new Vector3(5,3,2);
        var matrix = Matrix4x4.TRS(Vector3.zero, Quaternion.identity, scale);

        // determinant of a scaled matrix is volume of the parallelepiped
        // formed from its axes, in this case 5*3*2=30
        Debug.Log(matrix.determinant);
    }
}

See Determinant on Wikipedia for more details.

See Also: inverse property, Inverse3DAffine method.