simple 3D game

Phan 1:

Resource: model : ground.x , nen` cua game

Phan 1: Lop chua cac hang so:

Code:

using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

namespace FuelCell
{
    class GameConstants
    {
        //camera constants
        public const float NearClip = 1.0f;
        public const float FarClip = 1000.0f;
        public const float ViewAngle = 45.0f;
    }
}
Trong game co cac object, di chuyen, tuong tac, dc quy dinh boi class sau:
using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

namespace FuelCell
{
//start class cho object
    class GameObject
    {
//model nhap vao`
        public Model Model { get; set; }
//Vi tri cua object
        public Vector3 Position { get; set; }
//co hoat dong hay ko
        public bool IsActive { get; set; }
//bounding cho model
        public BoundingSphere BoundingSphere { get; set; }

        public GameObject()
        {
            Model = null;
            Position = Vector3.Zero;
            IsActive = false;
            BoundingSphere = new BoundingSphere();
        }
    }

//class the hien cho camera

Code:

 class Camera
    {
//vi tri camera
        public Vector3 AvatarHeadOffset { get; set; }
//diem target
        public Vector3 TargetOffset { get; set; }
        public Matrix ViewMatrix { get; set; }
        public Matrix ProjectionMatrix { get; set; }

        public Camera()
        {
            AvatarHeadOffset = new Vector3(0, 7, -15);
            TargetOffset = new Vector3(0, 5, 0);
            ViewMatrix = Matrix.Identity;
            ProjectionMatrix = Matrix.Identity;
        }
//Update camera (goc xoay, vi tri tinh tien cameraPosition va target, ti le man hinh)
        public void Update(float avatarYaw, Vector3 position, float aspectRatio)
        {
//camera chi xoay quanh truc Y
            Matrix rotationMatrix = Matrix.CreateRotationY(avatarYaw);
//Vector huong den bien doi:
            Vector3 transformedheadOffset = Vector3.Transform(AvatarHeadOffset, rotationMatrix);
//bien doi diem target
            Vector3 transformedReference = Vector3.Transform(TargetOffset, rotationMatrix);
//cac thanh phan cho viewMatrix
            Vector3 cameraPosition = position + transformedheadOffset;
            Vector3 cameraTarget = position + transformedReference;

            //Calculate the camera's view and projection matrices based on current values.
            ViewMatrix = Matrix.CreateLookAt(cameraPosition, cameraTarget, Vector3.Up);
            ProjectionMatrix = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(GameConstants.ViewAngle),
                aspectRatio, GameConstants.NearClip, GameConstants.FarClip);
        }
    }

}
Class cho game chinh':
using System;
using System.Collections.Generic;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Net;
using Microsoft.Xna.Framework.Storage;

namespace FuelCell
{
/// <summary>
/// This is the main type for your game
/// </summary>
public class FuelCellGame : Microsoft.Xna.Framework.Game
{
GraphicsDeviceManager graphics;
//dat
GameObject ground;
//camera
Camera gameCamera;

public FuelCellGame()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
}

/// <summary>
/// Allows the game to perform any initialization it needs to before starting to run.
/// This is where it can query for any required services and load any non-graphic
/// related content. Calling base.Initialize will enumerate through any components
/// and initialize them as well.
/// </summary>
protected override void Initialize()
{
ground = new GameObject();
gameCamera = new Camera();

base.Initialize();
}

/// <summary>
/// LoadContent will be called once per game and is the place to load
/// all of your content.
/// </summary>
protected override void LoadContent()
{
ground.Model = Content.Load<Model>("Models/ground");
}

/// <summary>
/// UnloadContent will be called once per game and is the place to unload
/// all content.
/// </summary>
protected override void UnloadContent()
{
// TODO: Unload any non ContentManager content here
}

/// <summary>
/// Allows the game to run logic such as updating the world,
/// checking for collisions, gathering input, and playing audio.
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values.</param>
protected override void Update(GameTime gameTime)
{
// Allows the game to exit
if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
this.Exit();
//goc xoay camera la 0f
float rotation = 0.0f;
Vector3 position = Vector3.Zero;
//update cho camera
gameCamera.Update(rotation, position, graphics.GraphicsDevice.Viewport.AspectRatio);

base.Update(gameTime);
}

/// <summary>
/// This is called when the game should draw itself.
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values.</param>
protected override void Draw(GameTime gameTime)
{
graphics.GraphicsDevice.Clear(Color.Black);

DrawTerrain(ground.Model);

base.Draw(gameTime);
}

//code de ve~ model ground
private void DrawTerrain(Model model)
{
foreach (ModelMesh mesh in model.Meshes)
{
foreach (BasicEffect effect in mesh.Effects)
{
effect.EnableDefaultLighting();
effect.PreferPerPixelLighting = true;
effect.World = Matrix.Identity;

// Use the matrices provided by the game camera
effect.View = gameCamera.ViewMatrix;
effect.Projection = gameCamera.ProjectionMatrix;
}
mesh.Draw();
}
}
}
}
Phan 2:
Bo sung them class constant:
//ship constants
//van toc player
public const float Velocity = 0.75f;
public const float TurnSpeed = 0.025f;
//Khoang cach xa nhat di chuyen
public const int MaxRange = 98;

Code:

Phan GameObject:
using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

namespace FuelCell
{
    class GameObject
    {
//cac thanh phan cua model
        public Model Model { get; set; }
        public Vector3 Position { get; set; }
        public BoundingSphere BoundingSphere { get; set; }
//thiet lap
        public GameObject()
        {
            Model = null;
            Position = Vector3.Zero;
            BoundingSphere = new BoundingSphere();
        }
    }

//cai an dc
    class FuelCell : GameObject
    {
        public bool Retrieved { get; set; }

        public FuelCell()
            : base()
        {
            Retrieved = false;
        }
//load model
        public void LoadContent(ContentManager content, string modelName)
        {
            Model = content.Load<Model>(modelName);
            Position = Vector3.Down;
        }
//Dua object len monitor
        public void Draw(Matrix view, Matrix projection)
        {
            Matrix translateMatrix = Matrix.CreateTranslation(Position);
            Matrix worldMatrix = translateMatrix;
//Neu no chua dc an

            if (!Retrieved)
            {
                foreach (ModelMesh mesh in Model.Meshes)
                {
                    foreach (BasicEffect effect in mesh.Effects)
                    {
                        effect.World = worldMatrix;
                        effect.View = view;
                        effect.Projection = projection;

                        effect.EnableDefaultLighting();
                        effect.PreferPerPixelLighting = true;
                    }
                    mesh.Draw();
                }
            }
        }


}
//Cac vat can player
class Barrier : GameObject
{
//chuoi ky tu ghi lai kieu vat can
public string BarrierType { get; set; }

public Barrier()
: base()
{
BarrierType = null;
}
//load content
public void LoadContent(ContentManager content, string modelName)
{
Model = content.Load<Model>(modelName);
BarrierType = modelName;
Position = Vector3.Down;
}
//Draw method
public void Draw(Matrix view, Matrix projection)
{
Matrix translateMatrix = Matrix.CreateTranslation(Position);
Matrix worldMatrix = translateMatrix;

foreach (ModelMesh mesh in Model.Meshes)
{
foreach (BasicEffect effect in mesh.Effects)
{
effect.World = worldMatrix;
effect.View = view;
effect.Projection = projection;

effect.EnableDefaultLighting();
effect.PreferPerPixelLighting = true;
}
mesh.Draw();
}
}

}
//cai player control
class FuelCarrier : GameObject
{
public float ForwardDirection { get; set; }
//khoang cach de ...
public int MaxRange { get; set; }

public FuelCarrier()
: base()
{
ForwardDirection = 0.0f;
MaxRange = GameConstants.MaxRange;
}

public void LoadContent(ContentManager content, string modelName)
{
Model = content.Load<Model>(modelName);
}

public void Draw(Matrix view, Matrix projection)
{
Matrix worldMatrix = Matrix.Identity;
Matrix rotationYMatrix = Matrix.CreateRotationY(ForwardDirection);
Matrix translateMatrix = Matrix.CreateTranslation(Position);

worldMatrix = rotationYMatrix * translateMatrix;

foreach (ModelMesh mesh in Model.Meshes)
{
foreach (BasicEffect effect in mesh.Effects)
{
effect.World = worldMatrix;
effect.View = view;
effect.Projection = projection;

effect.EnableDefaultLighting();
effect.PreferPerPixelLighting = true;
}
mesh.Draw();
}
}
}
//class cho camera, ko thay doi
class Camera
{
public Vector3 AvatarHeadOffset { get; set; }
public Vector3 TargetOffset { get; set; }
public Matrix ViewMatrix { get; set; }
public Matrix ProjectionMatrix { get; set; }

public Camera()
{
AvatarHeadOffset = new Vector3(0, 7, -15);
TargetOffset = new Vector3(0, 5, 0);
ViewMatrix = Matrix.Identity;
ProjectionMatrix = Matrix.Identity;
}

public void Update(float avatarYaw, Vector3 position, float aspectRatio)
{
Matrix rotationMatrix = Matrix.CreateRotationY(avatarYaw);

Vector3 transformedheadOffset = Vector3.Transform(AvatarHeadOffset, rotationMatrix);
Vector3 transformedReference = Vector3.Transform(TargetOffset, rotationMatrix);

Vector3 cameraPosition = position + transformedheadOffset;
Vector3 cameraTarget = position + transformedReference;

//Calculate the camera's view and projection matrices based on current values.
ViewMatrix = Matrix.CreateLookAt(cameraPosition, cameraTarget, Vector3.Up);
ProjectionMatrix = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(GameConstants.ViewAngle),
aspectRatio, GameConstants.NearClip, GameConstants.FarClip);
}
}
}

Code:

Game1.cs:
using System;
using System.Collections.Generic;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Net;
using Microsoft.Xna.Framework.Storage;

namespace FuelCell
{
    /// <summary>
    /// This is the main type for your game
    /// </summary>
    public class FuelCellGame : Microsoft.Xna.Framework.Game
    {
        GraphicsDeviceManager graphics;
//nen`
        GameObject ground;
//camera
        Camera gameCamera;
//tao so ngau nhien
        Random random;
//player
        FuelCarrier fuelCarrier;
//nhung cuc fuel
        FuelCell[] fuelCells;
//cac vat can
        Barrier[] barriers;

        public FuelCellGame()
        {
            graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";
        }

        /// <summary>
        /// Allows the game to perform any initialization it needs to before starting to run.
        /// This is where it can query for any required services and load any non-graphic
        /// related content.  Calling base.Initialize will enumerate through any components
        /// and initialize them as well.
        /// </summary>
        protected override void Initialize()
        {
            ground = new GameObject();
            gameCamera = new Camera();

            //Initialize and place fuel cell
            fuelCells = new FuelCell[1];
            fuelCells[0] = new FuelCell();
            fuelCells[0].LoadContent(Content, "Models/fuelcell");
            fuelCells[0].Position = new Vector3(0, 0, 15);

            //Initialize and place barriers
            barriers = new Barrier[3];

            barriers[0] = new Barrier();
            barriers[0].LoadContent(Content, "Models/cube10uR");
            barriers[0].Position = new Vector3(0, 0, 30);
            barriers[1] = new Barrier();
            barriers[1].LoadContent(Content, "Models/cylinder10uR");
            barriers[1].Position = new Vector3(15, 0, 30);
            barriers[2] = new Barrier();
            barriers[2].LoadContent(Content, "Models/pyramid10uR");
            barriers[2].Position = new Vector3(-15, 0, 30);

            //Initialize and place fuel carrier
            fuelCarrier = new FuelCarrier();
            fuelCarrier.LoadContent(Content, "Models/fuelcarrier");

            base.Initialize();
        }

        /// <summary>
        /// LoadContent will be called once per game and is the place to load
        /// all of your content.
        /// </summary>
        protected override void LoadContent()
        {
            ground.Model = Content.Load<Model>("Models/ground");
        }

        /// <summary>
        /// UnloadContent will be called once per game and is the place to unload
        /// all content.
        /// </summary>
        protected override void UnloadContent()
        {
            // TODO: Unload any non ContentManager content here
        }

        /// <summary>
        /// Allows the game to run logic such as updating the world,
        /// checking for collisions, gathering input, and playing audio.
        /// </summary>
        /// <param name="gameTime">Provides a snapshot of timing values.</param>
        protected override void Update(GameTime gameTime)
        {
            // Allows the game to exit
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
                this.Exit();
//camera cua chung ta la fixed, do do' khong co goc xoay, lay mac dinh //la 0f
            float rotation = 0.0f;
            Vector3 position = Vector3.Zero;
            gameCamera.Update(rotation, position, graphics.GraphicsDevice.Viewport.AspectRatio);

            base.Update(gameTime);
        }

        /// <summary>
        /// This is called when the game should draw itself.
        /// </summary>
        /// <param name="gameTime">Provides a snapshot of timing values.</param>
        protected override void Draw(GameTime gameTime)
        {
            graphics.GraphicsDevice.Clear(Color.Black);
//ve nen`
            DrawTerrain(ground.Model);

            fuelCells[0].Draw(gameCamera.ViewMatrix, gameCamera.ProjectionMatrix);
            foreach (Barrier barrier in barriers)
                barrier.Draw(gameCamera.ViewMatrix, gameCamera.ProjectionMatrix);
            fuelCarrier.Draw(gameCamera.ViewMatrix, gameCamera.ProjectionMatrix);

            base.Draw(gameTime);
        }

        /// <summary>
        /// Draws the game terrain, a simple blue grid.
        /// </summary>
        /// <param name="model">Model representing the game playing field.</param>
        private void DrawTerrain(Model model)
        {
            foreach (ModelMesh mesh in model.Meshes)
            {
                foreach (BasicEffect effect in mesh.Effects)
                {
                    effect.EnableDefaultLighting();
                    effect.PreferPerPixelLighting = true;
                    effect.World = Matrix.Identity;

                    // Use the matrices provided by the game camera
                    effect.View = gameCamera.ViewMatrix;
                    effect.Projection = gameCamera.ProjectionMatrix;
                }
                mesh.Draw();
            }
        }
    }
}
Phan 3:Viet game hoan chinh:
1.Khai bao cac hang so:
using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

namespace FuelCell
{
    class GameConstants
    {
        //DAnh cho camera
        public const float NearClip = 1.0f;
        public const float FarClip = 1000.0f;
        public const float ViewAngle = 45.0f;

        //danh cho player
        public const float Velocity = 0.75f;
        public const float TurnSpeed = 0.025f;
        public const int MaxRange = 98;

        //Kick thuoc cua terrain
        public const int MaxRangeTerrain = 98;
        public const int NumBarriers = 40;
        public const int NumFuelCells = 12;
        public const int MinDistance = 10;
        public const int MaxDistance = 90;
//thoi gian de thu nhat fuel
        public static readonly TimeSpan RoundTime = TimeSpan.FromSeconds(30.25);
        public const string StrTimeRemaining = "Time Remaining: ";
        public const string StrCellsFound = "Fuel Cells Retrieved: ";
        public const string StrGameWon = "Game Won !";
        public const string StrGameLost = "Game Lost !";
        public const string StrPlayAgain = "Press Enter/Start to play again or Esc/Back to quit";
        public const string StrInstructions1 = "Retrieve all Fuel Cells before time runs out.";
        public const string StrInstructions2 = "Control ship using keyboard (A, D, W, S) or the left thumbstick.";

        //Thay doi ti le bounding cua model
        public const float FuelCarrierBoundingSphereFactor = .8f;
        public const float FuelCellBoundingSphereFactor = .5f;
        public const float BarrierBoundingSphereFactor = .7f;
    }
}
2.Lop chua dinh nghia cac doi tuong cua game:
//lop nay` cho cac object khac thua` ke'
    class GameObject
    {
        public Model Model { get; set; }
        public Vector3 Position { get; set; }
        public BoundingSphere BoundingSphere { get; set; }

        public GameObject()
        {
            Model = null;
            Position = Vector3.Zero;
            BoundingSphere = new BoundingSphere();
        }
//bounding dua tren cac mesh cua model
        protected BoundingSphere CalculateBoundingSphere()
        {
            BoundingSphere mergedSphere = new BoundingSphere();
            BoundingSphere[] boundingSpheres;
            int index = 0;
            int meshCount = Model.Meshes.Count;

            boundingSpheres = new BoundingSphere[meshCount];
            foreach (ModelMesh mesh in Model.Meshes)
            {
                boundingSpheres[index++] = mesh.BoundingSphere;
            }

            mergedSphere = boundingSpheres[0];
            if ((Model.Meshes.Count) > 1)
            {
                index = 1;
                do
                {
                    mergedSphere = BoundingSphere.CreateMerged(mergedSphere, boundingSpheres[index]);
                    index++;
                } while (index < Model.Meshes.Count);
            }
            mergedSphere.Center.Y = 0;
            return mergedSphere;
        }
//Draw cai model :
        internal void DrawBoundingSphere(Matrix view, Matrix projection, GameObject boundingSphereModel)
        {
            Matrix scaleMatrix = Matrix.CreateScale(BoundingSphere.Radius);
            Matrix translateMatrix = Matrix.CreateTranslation(BoundingSphere.Center);
            Matrix worldMatrix = scaleMatrix * translateMatrix;

            foreach (ModelMesh mesh in boundingSphereModel.Model.Meshes)
            {
                foreach (BasicEffect effect in mesh.Effects)
                {
                    effect.World = worldMatrix;
                    effect.View = view;
                    effect.Projection = projection;
                }
                mesh.Draw();
            }
        }
    }
3.Lop cho fuel, cai chung ta thu nhat
[code]    class FuelCell : GameObject
    {
//da dc thu nhat hay chua:
        public bool Retrieved { get; set; }

        public FuelCell()
            : base()
        {
            Retrieved = false;
        }

        public void LoadContent(ContentManager content, string modelName)
        {
            Model = content.Load<Model>(modelName);
            Position = Vector3.Down;

            BoundingSphere = CalculateBoundingSphere();

            BoundingSphere scaledSphere;
            scaledSphere = BoundingSphere;
            scaledSphere.Radius *= GameConstants.FuelCellBoundingSphereFactor;
//bounding sau khi da dc scale:
            BoundingSphere = new BoundingSphere(scaledSphere.Center, scaledSphere.Radius);
        }

        public void Draw(Matrix view, Matrix projection)
        {
//di chuyen object sang vi tri' xac dinh
            Matrix translateMatrix = Matrix.CreateTranslation(Position);
            Matrix worldMatrix = translateMatrix;

            foreach (ModelMesh mesh in Model.Meshes)
            {
                foreach (BasicEffect effect in mesh.Effects)
                {
                    effect.World = worldMatrix;
                    effect.View = view;
                    effect.Projection = projection;

                    effect.EnableDefaultLighting();
                    effect.PreferPerPixelLighting = true;
                }
                mesh.Draw();
            }
        }
//KT va cham voi mot bounding cua object di chuyen (player)
        internal void Update(BoundingSphere vehicleBoundingSphere)
        {
            if (vehicleBoundingSphere.Intersects(this.BoundingSphere))
//da co va cham
                this.Retrieved = true;
        }
    }[/code]
4.class cho cac vat can
    class Barrier : GameObject
    {
        public string BarrierType { get; set; }

        public Barrier()
            : base()
        {
            BarrierType = null;
        }

        public void LoadContent(ContentManager content, string modelName)
        {
            Model = content.Load<Model>(modelName);
//kieu cua vat can trung voi ten model cua no'
            BarrierType = modelName;
            Position = Vector3.Down;
            BoundingSphere = CalculateBoundingSphere();

            BoundingSphere scaledSphere;
            scaledSphere = BoundingSphere;
            scaledSphere.Radius *= GameConstants.BarrierBoundingSphereFactor;unding sau khi scale
//b
            BoundingSphere = new BoundingSphere(scaledSphere.Center, scaledSphere.Radius);
        }

        public void Draw(Matrix view, Matrix projection)
        {
//dat object o vi tri xac dinh
            Matrix translateMatrix = Matrix.CreateTranslation(Position);
            Matrix worldMatrix = translateMatrix;

            foreach (ModelMesh mesh in Model.Meshes)
            {
                foreach (BasicEffect effect in mesh.Effects)
                {
                    effect.World = worldMatrix;
                    effect.View = view;
                    effect.Projection = projection;

                    effect.EnableDefaultLighting();
                    effect.PreferPerPixelLighting = true;
                }
                mesh.Draw();
            }
        }
    }
//class cua player
    class FuelCarrier : GameObject
    {
//goc xoay di chuyen
        public float ForwardDirection { get; set; }
//khoang cach toi da di chuyen
        public int MaxRange { get; set; }

        public FuelCarrier()
            : base()
        {
            ForwardDirection = 0.0f;
            MaxRange = GameConstants.MaxRange;
        }

        public void LoadContent(ContentManager content, string modelName)
        {
            Model = content.Load<Model>(modelName);
            BoundingSphere = CalculateBoundingSphere();

            BoundingSphere scaledSphere;
            scaledSphere = BoundingSphere;
            scaledSphere.Radius *= GameConstants.FuelCarrierBoundingSphereFactor;
//bounding sau khi scale
            BoundingSphere = new BoundingSphere(scaledSphere.Center, scaledSphere.Radius);
        }
//dat lai vi tri cho player
        internal void Reset()
        {
            Position = Vector3.Zero;
            ForwardDirection = 0f;
        }

        public void Draw(Matrix view, Matrix projection)
        {
            Matrix worldMatrix = Matrix.Identity;
//goc xoay quanh truc Y
            Matrix rotationYMatrix = Matrix.CreateRotationY(ForwardDirection);
            Matrix translateMatrix = Matrix.CreateTranslation(Position);
//object tu xoay quanh truc Y cua model
            worldMatrix = rotationYMatrix * translateMatrix;

            foreach (ModelMesh mesh in Model.Meshes)
            {
                foreach (BasicEffect effect in mesh.Effects)
                {
                    effect.World = worldMatrix;
                    effect.View = view;
                    effect.Projection = projection;

                    effect.EnableDefaultLighting();
                    effect.PreferPerPixelLighting = true;
                }
                mesh.Draw();
            }
        }
//Control player
        public void Update(GamePadState gamepadState, KeyboardState keyboardState, Barrier[] barriers)
        {
            Vector3 futurePosition = Position;
            float turnAmount = 0;
//xoay sang trai hay phai
            if (keyboardState.IsKeyDown(Keys.A))
            {
                turnAmount = 1;
            }
            else if(keyboardState.IsKeyDown(Keys.D))
            {
                turnAmount = -1;
            }
            else if(gamepadState.ThumbSticks.Left.X != 0)
            {
                turnAmount = -gamepadState.ThumbSticks.Left.X;
            }
//tang goc xoay khi chung ta bam nut'! kem` voi 1 const kiem` che' toi' //do.
            ForwardDirection += turnAmount * GameConstants.TurnSpeed;
            Matrix orientationMatrix = Matrix.CreateRotationY(ForwardDirection);
//di chyen toi' va` lui
            Vector3 movement = Vector3.Zero;
            if (keyboardState.IsKeyDown(Keys.W))
            {
                movement.Z = 1;
            }
            else if(keyboardState.IsKeyDown(Keys.S))
            {
                movement.Z = -1;
            }
            else if (gamepadState.ThumbSticks.Left.Y != 0)
            {
                movement.Z = gamepadState.ThumbSticks.Left.Y;
            }
//toa do. moi' cua player, bien doi vi tri movement theo viec xoay quanh 1 ma tran xoay orientationMatrix
            Vector3 speed = Vector3.Transform(movement, orientationMatrix);
//Kiem? Soat no voi const
            speed *= GameConstants.Velocity;
//Vi tri moi; se dc cong them vao vi tri hien tai
            futurePosition = Position + speed;
//KT xem vi tri moi co hop ly hay ko
            if (ValidateMovement(futurePosition, barriers))
            {
//Neu no hop ly', future se tro thanh present!
                Position = futurePosition;
//bounding cua player can thay doi khi no di chuyen:
                BoundingSphere updatedSphere;
                updatedSphere = BoundingSphere;

                updatedSphere.Center.X = Position.X;
                updatedSphere.Center.Z = Position.Z;
//bounding sau khi update!
                BoundingSphere = new BoundingSphere(updatedSphere.Center, updatedSphere.Radius);
            }
        }
//method KT diem future co hop ly hay ko
        private bool ValidateMovement(Vector3 futurePosition, Barrier[] barriers)
        {
            BoundingSphere futureBoundingSphere = BoundingSphere;
            futureBoundingSphere.Center.X = futurePosition.X;
            futureBoundingSphere.Center.Z = futurePosition.Z;
           
            //Khoang cach ma player di dc toi da
            if ((Math.Abs(futurePosition.X) > MaxRange) || (Math.Abs(futurePosition.Z) > MaxRange))
                return false;
            //Don't allow driving through a barrier
            if (CheckForBarrierCollision(futureBoundingSphere, barriers))
                return false;

            return true;
        }
//KT va cham voi cac vat can
        private bool CheckForBarrierCollision(BoundingSphere vehicleBoundingSphere, Barrier[] barriers)
        {
            for (int curBarrier = 0; curBarrier < barriers.Length; curBarrier++)
            {
                if (vehicleBoundingSphere.Intersects(barriers[curBarrier].BoundingSphere))
                    return true;
            }
            return false;
        }
    }
6.class cho camera,
 [code]  class Camera
    {
        public Vector3 AvatarHeadOffset { get; set; }
        public Vector3 TargetOffset { get; set; }
        public Matrix ViewMatrix { get; set; }
        public Matrix ProjectionMatrix { get; set; }

        public Camera()
        {
            AvatarHeadOffset = new Vector3(0, 7, -15);
            TargetOffset = new Vector3(0, 5, 0);
            ViewMatrix = Matrix.Identity;
            ProjectionMatrix = Matrix.Identity;
        }
//cho biet goc ma` camera xoay quanh truc Y
//Goc nay trung voi goc ma` player phai xoay:
        public void Update(float avatarYaw, Vector3 position, float aspectRatio)
        {
            Matrix rotationMatrix = Matrix.CreateRotationY(avatarYaw);

            Vector3 transformedheadOffset = Vector3.Transform(AvatarHeadOffset, rotationMatrix);
            Vector3 transformedReference = Vector3.Transform(TargetOffset, rotationMatrix);

            Vector3 cameraPosition = position + transformedheadOffset;
            Vector3 cameraTarget = position + transformedReference;

            //Calculate the camera's view and projection matrices based on current values.
            ViewMatrix = Matrix.CreateLookAt(cameraPosition, cameraTarget, Vector3.Up);
            ProjectionMatrix = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(GameConstants.ViewAngle),
                aspectRatio, GameConstants.NearClip, GameConstants.FarClip);
        }
    }
}[/code]
7.Game1.cs:
using System;
using System.Collections.Generic;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Net;
using Microsoft.Xna.Framework.Storage;

namespace FuelCell
{
//cac man` cua game
    public enum GameState { Loading, Running, Won, Lost }

    /// <summary>
    /// This is the main type for your game
    /// </summary>
    public class FuelCellGame : Microsoft.Xna.Framework.Game
    {
        GraphicsDeviceManager graphics;
//tao phim release
        KeyboardState lastKeyboardState = new KeyboardState();
        KeyboardState currentKeyboardState = new KeyboardState();
        GamePadState lastGamePadState = new GamePadState();
        GamePadState currentGamePadState = new GamePadState();
//so luong fuel da nhat dc
        int retrievedFuelCells = 0;
//thoi diem bat dau`,dem' thoi gian da qua, Thoi gian toi' da
        TimeSpan startTime, roundTimer, roundTime;
        Random random;
        SpriteBatch spriteBatch;
        SpriteFont statsFont;
//dat man` hien tai la "loading"
        GameState currentGameState = GameState.Loading;

        GameObject ground;
        Camera gameCamera;
//bounding cua...
        GameObject boundingSphere;

        FuelCarrier fuelCarrier;
        FuelCell[] fuelCells;
        Barrier[] barriers;

        public FuelCellGame()
        {
            graphics = new GraphicsDeviceManager(this);
            graphics.PreferredBackBufferWidth = 853;
            graphics.PreferredBackBufferHeight = 480;

            Content.RootDirectory = "Content";
//roundTime = 30.25f
            roundTime = GameConstants.RoundTime;
            random = new Random();
        }

        /// <summary>
        /// Allows the game to perform any initialization it needs to before starting to run.
        /// This is where it can query for any required services and load any non-graphic
        /// related content.  Calling base.Initialize will enumerate through any components
        /// and initialize them as well.
        /// </summary>
        protected override void Initialize()
        {
            ground = new GameObject();
            gameCamera = new Camera();
            boundingSphere = new GameObject();

            base.Initialize();
        }

        /// <summary>
        /// LoadContent will be called once per game and is the place to load
        /// all of your content.
        /// </summary>
        protected override void LoadContent()
        {
//load ground
            ground.Model = Content.Load<Model>("Models/ground");
            boundingSphere.Model = Content.Load<Model>("Models/sphere1uR");

            spriteBatch = new SpriteBatch(GraphicsDevice);
//load font
            statsFont = Content.Load<SpriteFont>("Fonts/StatsFont");

            //Thiet lap cac fuel
            fuelCells = new FuelCell[GameConstants.NumFuelCells];
//lap tat ca cac fuel
            for (int index = 0; index < fuelCells.Length; index++)
            {
                fuelCells[index] = new FuelCell();
                fuelCells[index].LoadContent(Content, "Models/fuelcell");
            }

            //Initialize barriers
            barriers = new Barrier[GameConstants.NumBarriers];
            int randomBarrier = random.Next(3);
            string barrierName = null;

            for (int index = 0; index < barriers.Length; index++)
            {

                switch (randomBarrier)
                {
                    case 0:
                        barrierName = "Models/cube10uR";
                        break;
                    case 1:
                        barrierName = "Models/cylinder10uR";
                        break;
                    case 2:
                        barrierName = "Models/pyramid10uR";
                        break;
                }
                barriers[index] = new Barrier();
                barriers[index].LoadContent(Content, barrierName);
                randomBarrier = random.Next(3);
            }
//method dat fuel va barrier vao` vi tri phu hop
            PlaceFuelCellsAndBarriers();

            //Initialize fuel carrier
            fuelCarrier = new FuelCarrier();
            fuelCarrier.LoadContent(Content, "Models/fuelcarrier");
        }
//dat cac thanh phan tren vao` vi tri
        private void PlaceFuelCellsAndBarriers()
        {
            int min = GameConstants.MinDistance;
            int max = GameConstants.MaxDistance;
            Vector3 tempCenter;

            //place fuel cells
            foreach (FuelCell cell in fuelCells)
            {
//lay ngau nhien vi tri fuel
                cell.Position = GenerateRandomPosition(min, max);

                tempCenter.X = cell.Position.X;
                tempCenter.Y = 0;
                tempCenter.Z = cell.Position.Z;
//bounding cho fuel
                cell.BoundingSphere = new BoundingSphere(tempCenter, cell.BoundingSphere.Radius);
                cell.Retrieved = false;
            }

            //place barriers
            foreach (Barrier barrier in barriers)
            {
//dat ngau nhien vat can
                barrier.Position = GenerateRandomPosition(min, max);

                tempCenter.X = barrier.Position.X;
                tempCenter.Y = 0;
                tempCenter.Z = barrier.Position.Z;
                barrier.BoundingSphere = new BoundingSphere(tempCenter, barrier.BoundingSphere.Radius);
            }
        }
//ham dat ngau nhien vi tri'
        private Vector3 GenerateRandomPosition(int min, int max)
        {
            int xValue, zValue;
            do
            {
                xValue = random.Next(min, max);
                zValue = random.Next(min, max);
//50% khi muon  dat nguoc lai vi tri cua object
                if (random.Next(100) % 2 == 0)
                    xValue *= -1;
                if (random.Next(100) % 2 == 0)
                    zValue *= -1;

            }
//Vi tri chi thoa man neu no ko co van de`
while (IsOccupied(xValue, zValue));

            return new Vector3(xValue, 0, zValue);
        }

        private bool IsOccupied(int xValue, int zValue)
        {
            foreach (GameObject currentObj in fuelCells)
            {
                if (((int)(MathHelper.Distance(xValue, currentObj.Position.X)) < 15) &&
                    ((int)(MathHelper.Distance(zValue, currentObj.Position.Z)) < 15))
                    return true;
            }

            foreach (GameObject currentObj in barriers)
            {
                if (((int)(MathHelper.Distance(xValue, currentObj.Position.X)) < 15) &&
                    ((int)(MathHelper.Distance(zValue, currentObj.Position.Z)) < 15))
                    return true;
            }
            return false;
        }

        /// <summary>
        /// UnloadContent will be called once per game and is the place to unload
        /// all content.
        /// </summary>
        protected override void UnloadContent()
        {
            // TODO: Unload any non ContentManager content here
        }

        /// <summary>
        /// Allows the game to run logic such as updating the world,
        /// checking for collisions, gathering input, and playing audio.
        /// </summary>
        /// <param name="gameTime">Provides a snapshot of timing values.</param>
        protected override void Update(GameTime gameTime)
        {
            float aspectRatio = graphics.GraphicsDevice.Viewport.AspectRatio;
            lastKeyboardState = currentKeyboardState;
            currentKeyboardState = Keyboard.GetState();
            lastGamePadState = currentGamePadState;
            currentGamePadState = GamePad.GetState(PlayerIndex.One);
//update cho Loading screen
            if (currentGameState == GameState.Loading)
            {
//release phim Enter
                if ((lastKeyboardState.IsKeyDown(Keys.Enter) && (currentKeyboardState.IsKeyUp(Keys.Enter))) ||
                    currentGamePadState.Buttons.Start == ButtonState.Pressed)
                {
// bat dau cho play screen
                    roundTimer = roundTime;
                    currentGameState = GameState.Running;
                }
            }
//update cho play screen
            if ((currentGameState == GameState.Running))
            {
//Dieu khien player
                fuelCarrier.Update(currentGamePadState, currentKeyboardState, barriers);
//dieu khien camera
                gameCamera.Update(fuelCarrier.ForwardDirection, fuelCarrier.Position, aspectRatio);
                retrievedFuelCells = 0;
                foreach (FuelCell fuelCell in fuelCells)
                {
//KT va cham voi player
                    fuelCell.Update(fuelCarrier.BoundingSphere);
//dem sl fuel thu nhat dc
                    if (fuelCell.Retrieved)
                    {
                        retrievedFuelCells++;
                    }
                }
//KT dieu khien Win
                if (retrievedFuelCells == GameConstants.NumFuelCells)
                {
                    currentGameState = GameState.Won;
                }
//Thoi gian la 30.25f giay va` dang giam dan`
                roundTimer -= gameTime.ElapsedGameTime;
                if ((roundTimer < TimeSpan.Zero) && (retrievedFuelCells != GameConstants.NumFuelCells))
                {
//nguoi choi se thua
                    currentGameState = GameState.Lost;
                }
            }

            if ((currentGameState == GameState.Won) || (currentGameState == GameState.Lost))
            {
                // Bat dau` lai tro` choi (play screen)
                if ((lastKeyboardState.IsKeyDown(Keys.Enter) && (currentKeyboardState.IsKeyUp(Keys.Enter))) ||
                    currentGamePadState.Buttons.Start == ButtonState.Pressed)
                    ResetGame(gameTime, aspectRatio);
            }

            base.Update(gameTime);
        }

        private void ResetGame(GameTime gameTime, float aspectRatio)
        {
            fuelCarrier.Reset();
            gameCamera.Update(fuelCarrier.ForwardDirection, fuelCarrier.Position, aspectRatio);
//tao lai cac barriers
            InitializeGameField();

            retrievedFuelCells = 0;
            startTime = gameTime.TotalGameTime;
            roundTimer = roundTime;
            currentGameState = GameState.Running;
        }

        private void InitializeGameField()
        {
            //Initialize barriers
            barriers = new Barrier[GameConstants.NumBarriers];
            int randomBarrier = random.Next(3);
            string barrierName = null;

            for (int index = 0; index < GameConstants.NumBarriers; index++)
            {
                switch (randomBarrier)
                {
                    case 0:
                        barrierName = "Models/cube10uR";
                        break;
                    case 1:
                        barrierName = "Models/cylinder10uR";
                        break;
                    case 2:
                        barrierName = "Models/pyramid10uR";
                        break;
                }
                barriers[index] = new Barrier();
                barriers[index].LoadContent(Content, barrierName);
                randomBarrier = random.Next(3);
            }
            PlaceFuelCellsAndBarriers();
        }

        /// <summary>
        /// This is called when the game should draw itself.
        /// </summary>
        /// <param name="gameTime">Provides a snapshot of timing values.</param>
        protected override void Draw(GameTime gameTime)
        {
            graphics.GraphicsDevice.Clear(Color.Black);
//tuy theo man` ma` draw
            switch (currentGameState)
            {
                case GameState.Loading:
                    DrawSplashScreen();
                    break;
                case GameState.Running:
                    DrawGameplayScreen();
                    break;
                case GameState.Won:
                    DrawWinOrLossScreen(GameConstants.StrGameWon);
                    break;
                case GameState.Lost:
                    DrawWinOrLossScreen(GameConstants.StrGameLost);
                    break;
            };

            base.Draw(gameTime);
        }

        /// <summary>
        /// Draws the game terrain, a simple blue grid.
        /// </summary>
        /// <param name="model">Model representing the game playing field.</param>
        private void DrawTerrain(Model model)
        {
            foreach (ModelMesh mesh in model.Meshes)
            {
                foreach (BasicEffect effect in mesh.Effects)
                {
                    effect.EnableDefaultLighting();
                    effect.PreferPerPixelLighting = true;
                    effect.World = Matrix.Identity;

                    // Use the matrices provided by the game camera
                    effect.View = gameCamera.ViewMatrix;
                    effect.Projection = gameCamera.ProjectionMatrix;
                }
                mesh.Draw();
            }
        }
//man gioi thieu
        private void DrawSplashScreen()
        {
            float xOffsetText, yOffsetText;
            Vector2 viewportSize = new Vector2(GraphicsDevice.Viewport.Width, GraphicsDevice.Viewport.Height);
            Vector2 strCenter;

            graphics.GraphicsDevice.Clear(Color.SteelBlue);

            xOffsetText = yOffsetText = 0;
            Vector2 strInstructionsSize = statsFont.MeasureString(GameConstants.StrInstructions1);
            Vector2 strPosition;
            strCenter = new Vector2(strInstructionsSize.X / 2, strInstructionsSize.Y / 2);

            yOffsetText = (viewportSize.Y / 2 - strCenter.Y);
            xOffsetText = (viewportSize.X / 2 - strCenter.X);
            strPosition = new Vector2(xOffsetText, yOffsetText);

            spriteBatch.Begin();
            spriteBatch.DrawString(statsFont, GameConstants.StrInstructions1, strPosition, Color.White);

            strInstructionsSize = statsFont.MeasureString(GameConstants.StrInstructions2);
            strCenter = new Vector2(strInstructionsSize.X / 2, strInstructionsSize.Y / 2);
            yOffsetText = (viewportSize.Y / 2 - strCenter.Y) + statsFont.LineSpacing;
            xOffsetText = (viewportSize.X / 2 - strCenter.X);
            strPosition = new Vector2(xOffsetText, yOffsetText);

            spriteBatch.DrawString(statsFont, GameConstants.StrInstructions2, strPosition, Color.LightGray);
            spriteBatch.End();

            //re-enable depth buffer after sprite batch disablement
            GraphicsDevice.RenderState.DepthBufferEnable = true;
            GraphicsDevice.RenderState.AlphaBlendEnable = false;
            GraphicsDevice.RenderState.AlphaTestEnable = false;
            GraphicsDevice.SamplerStates[0].AddressU = TextureAddressMode.Wrap;
            GraphicsDevice.SamplerStates[0].AddressV = TextureAddressMode.Wrap;
        }
//thang hay thua
        private void DrawWinOrLossScreen(string gameResult)
        {
            float xOffsetText, yOffsetText;
            Vector2 viewportSize = new Vector2(GraphicsDevice.Viewport.Width, GraphicsDevice.Viewport.Height);
            Vector2 strCenter;

            xOffsetText = yOffsetText = 0;
            Vector2 strResult = statsFont.MeasureString(gameResult);
            Vector2 strPlayAgainSize = statsFont.MeasureString(GameConstants.StrPlayAgain);
            Vector2 strPosition;
            strCenter = new Vector2(strResult.X / 2, strResult.Y / 2);

            yOffsetText = (viewportSize.Y / 2 - strCenter.Y);
            xOffsetText = (viewportSize.X / 2 - strCenter.X);
            strPosition = new Vector2(xOffsetText, yOffsetText);

            spriteBatch.Begin();
            spriteBatch.DrawString(statsFont, gameResult, strPosition, Color.Red);

            strCenter = new Vector2(strPlayAgainSize.X / 2, strPlayAgainSize.Y / 2);
            yOffsetText = (viewportSize.Y / 2 - strCenter.Y) + (float)statsFont.LineSpacing;
            xOffsetText = (viewportSize.X / 2 - strCenter.X);
            strPosition = new Vector2(xOffsetText, yOffsetText);
            spriteBatch.DrawString(statsFont, GameConstants.StrPlayAgain, strPosition, Color.AntiqueWhite);

            spriteBatch.End();

            //re-enable depth buffer after sprite batch disablement
            GraphicsDevice.RenderState.DepthBufferEnable = true;
            GraphicsDevice.RenderState.AlphaBlendEnable = false;
            GraphicsDevice.RenderState.AlphaTestEnable = false;
            GraphicsDevice.SamplerStates[0].AddressU = TextureAddressMode.Wrap;
            GraphicsDevice.SamplerStates[0].AddressV = TextureAddressMode.Wrap;
        }
//playerScreen
        private void DrawGameplayScreen()
        {   
//draw model
            DrawTerrain(ground.Model);
            foreach (FuelCell fuelCell in fuelCells)
            {
                if (!fuelCell.Retrieved)
                {
                    fuelCell.Draw(gameCamera.ViewMatrix, gameCamera.ProjectionMatrix);
                }
            }
            foreach (Barrier barrier in barriers)
            {
                barrier.Draw(gameCamera.ViewMatrix, gameCamera.ProjectionMatrix);
            }

            fuelCarrier.Draw(gameCamera.ViewMatrix, gameCamera.ProjectionMatrix);
            DrawStats();
        }

        private void DrawStats()
        {
            float xOffsetText, yOffsetText;
            string str1 = GameConstants.StrTimeRemaining;
            string str2 = GameConstants.StrCellsFound + retrievedFuelCells.ToString() + " of " + GameConstants.NumFuelCells.ToString();
            Rectangle rectSafeArea;

            str1 += (roundTimer.Seconds).ToString();

            //Calculate str1 position
            rectSafeArea = GetTitleSafeArea(GraphicsDevice.Viewport);

            xOffsetText = rectSafeArea.X;
            yOffsetText = rectSafeArea.Y;

            Vector2 strSize = statsFont.MeasureString(str1);
            Vector2 strPosition = new Vector2(xOffsetText + 10, yOffsetText);

            spriteBatch.Begin();
            spriteBatch.DrawString(statsFont, str1, strPosition, Color.White);
            strPosition.Y += strSize.Y;
            spriteBatch.DrawString(statsFont, str2, strPosition, Color.White);
            spriteBatch.End();

            //re-enable depth buffer after sprite batch disablement
            GraphicsDevice.RenderState.DepthBufferEnable = true;
            GraphicsDevice.RenderState.AlphaBlendEnable = false;
            GraphicsDevice.RenderState.AlphaTestEnable = false;
            GraphicsDevice.SamplerStates[0].AddressU = TextureAddressMode.Wrap;
            GraphicsDevice.SamplerStates[0].AddressV = TextureAddressMode.Wrap;
        }

        private Rectangle GetTitleSafeArea(Viewport viewport)
        {
            Rectangle retval = new Rectangle(viewport.X, viewport.Y, viewport.Width, viewport.Height);
#if XBOX
            retval = viewport.TitleSafeArea;
#endif
            return retval;
        }
    }
}

Source: http://www.mediafire.com/?2qodaznmizm