跟随相机XNA 4.0 C＃

Question

How to change target camera into follow?

Target:

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;


namespace Flight
{
    public class FollowCamera : CCamera
    {

        public Vector3 Target { get; set; }

        public FollowCamera(Vector3 Position, Vector3 Target,
                    GraphicsDevice graphicsDevice)
            : base(graphicsDevice)
        {
            this.Position = Position;
            this.Target = Target;
        }

        public override void Update()
        {
            //Missing lines of code used to determine 
            //the up vector
            Vector3 forward = Target - Position;
            Vector3 right = Vector3.Cross(forward, Vector3.Up);
            Vector3 up = Vector3.Cross(right, forward);

            this.View = Matrix.CreateLookAt(Position,
                    Target, up);
        }
    }

}

I do have a clue to use this line of code with some modification plus add to it the length how far camera should be behind target. This line of code makes my ship ove arround the screen now i need to make sure the camera moves with the ship. Help please

 this.local = Matrix.CreateFromYawPitchRoll(orientation.Y, orientation.X, orientation.Z) * Matrix.CreateTranslation(position.X, position.Y, position.Z) * this.local;

Answer 1

You have to attach the camera to your ship, calculate the camera position and target with its position

interface IPositionable { Vector3 Position }


class FollowCamera{

    public IPositionable ObjectToFollow;

    public FollowCamera(Vector3 RelativePosition)
    {
        this.RelativePosition = relativePosition
    }

    public override void Update()
    {
        //Missing lines of code used to determine 
        //the up vector
        Vector3 forward = Target - Position;
        Vector3 right = Vector3.Cross(forward, Vector3.Up);
        Vector3 up = Vector3.Cross(right, forward);

        Position = ObjectToFollow.Position - RelativePosition;
        Target = ObjectToFollow.Position;

        this.View = Matrix.CreateLookAt(Position,
                Target, up);
    }
}

If you consider the forward vector of the ship and interpolate this values with a easing function, the movement can be very cool and smooth.