Add Double Jump to First Person Controller - ParkinT/unity3dlabs GitHub Wiki

In order to add the capability to Double Jump when using the RigidbodyFirstPersonController Prefab, locate this code in FixedUpdate.

            if (m_IsGrounded)
            {
                m_RigidBody.drag = 5f;

                if (m_Jump)
                {
                    m_RigidBody.drag = 0f;
                    m_RigidBody.velocity = new Vector3(m_RigidBody.velocity.x, 0f, m_RigidBody.velocity.z);
                    m_RigidBody.AddForce(new Vector3(0f, movementSettings.JumpForce, 0f), ForceMode.Impulse);
                    m_Jumping = true;
                }

                if (!m_Jumping && Mathf.Abs(input.x) < float.Epsilon && Mathf.Abs(input.y) < float.Epsilon && m_RigidBody.velocity.magnitude < 1f)
                {
                    m_RigidBody.Sleep();
                }
            }
            else
            {
              //double Jump
              if (m_Jump) {
                m_Jump = false;
                m_RigidBody.velocity = new Vector3(m_RigidBody.velocity.x, 0f, m_RigidBody.velocity.z);
                m_RigidBody.AddForce(new Vector3(0f, movementSettings.DoubleJumpForce, 0f), ForceMode.Impulse);
              }
                m_RigidBody.drag = 0f;
                if (m_PreviouslyGrounded && !m_Jumping)
                {
                    StickToGroundHelper();
                }
            }
            m_Jump = false;
        }

The if block near the comment "double Jump" represent additional code. Also, add this with the other Public variables: public float DoubleJumpForce = 45f;