Generic XNA - SM3 Fog

So here is the SM3 (Shader Model 3) HLSL fog. Now this is taken pretty much 99% from Leaf's example, but thought I would comment on how easy this technique is to put into your existing shaders.

I also found that adding this to a shader pushes the operation count up a fair bit, the limit in SM2 is 64 operations per shader, so 128 in all, 64 in the Vertex Shader and another 64 in the Pixel Shader. So What I did was put the fog code into a second pass so giving me another 64x64 operation slots to play with.



So here are the shaders:

This first shader is the one used for the buildings you see in the shots, it is a single pass and a simple texture shader.

ShaderFog.fx

float4x4 World : World;
float4x4 WorldViewProject : WorldViewProjection;
float3 EyePosition : CameraPosition;
texture thisTexture;
float3  LightPos  = (0,-1,0);

float4 ambient = {0.25, 0.25, 0.25, 1.0};
float4 diffuse = {1.0, 1.0, 1.0, 1.0};
float4 specularColor = {0.2, 0.2, 0.2, 1.0};
float shininess = 40;

float fogNear = 10;
float fogFar = 100;
float fogAltitudeScale = 10;
float fogThinning = 100;
float4 fogColor = {0.5, 0.5, 0.5, 1.0};

sampler TextureSampler = sampler_state
{
   Texture = <thisTexture>;
};

struct VS_INPUT
{
   float4 Position : POSITION0;
   float2 Texcoord : TEXCOORD0;
   float3 Normal : NORMAL0;
};

struct VS_OUTPUT
{
   float4 Position : POSITION;
   float2 Texcoord : TEXCOORD0;
   float3 Normal : TEXCOORD1;    
   float3 WorldPos : TEXCOORD2;
};
struct PS_INPUT
{
   float4 Position : TEXCOORD4;
   float2 Texcoord : TEXCOORD0;
   float3 Normal : TEXCOORD1;    
   float3 WorldPos : TEXCOORD2;
};

float4 blinn2(
       float3 N,
       float3 L,
       float3 V,
       uniform float4 diffuseColor,
       uniform float4 specularColor,
       uniform float shininess)
{
   float3 H = normalize(V+L);
   float4 lighting = lit(dot(L,N), dot(H,N), shininess);
   return diffuseColor*lighting.y + specularColor*lighting.z;
}


VS_OUTPUT Transform(VS_INPUT Input)
{
   VS_OUTPUT Output;

   Output.WorldPos = mul(Input.Position,World);
   Output.Position = mul(Input.Position, WorldViewProject);
   Output.Texcoord = Input.Texcoord;
   Output.Normal = mul(Input.Normal,World);

   return Output;
}

float4 Texture(PS_INPUT Input) : COLOR0
{
   float4 colorMap = tex2D(TextureSampler, Input.Texcoord.xy) * 1.5;
   float3 N = normalize(Input.Normal);
   float3 V = normalize(EyePosition - Input.WorldPos);
   float3 L = normalize(LightPos - Input.WorldPos);
   
   float4 C = ambient*colorMap;
   
   C += blinn2(N, L, V, colorMap * diffuse, specularColor * colorMap.a, shininess);
   float d = length(Input.WorldPos - EyePosition);
   float l = saturate((d - fogNear) / (fogFar - fogNear) / clamp(Input.Position.y / fogAltitudeScale + 1, 1, fogThinning));
   return lerp(C, fogColor, l);    
};

technique TransformTexture
{
   pass P0
   {
       VertexShader = compile vs_1_1 Transform();
       PixelShader  = compile ps_2_0 Texture();
   }
}

This is the shader I use for the floor tile, again this is a single pass. Just a variation on the theam really.

Floor.fx

float4x4 World : World;
float4x4 WorldViewProject : WorldViewProjection;
float3 EyePosition : CameraPosition;
texture thisTexture;
float3  LightPos  = (0,-1,0);

float4 ambient = {0.25, 0.25, 0.25, 1.0};
float4 diffuse = {1.0, 1.0, 1.0, 1.0};
float4 specularColor = {0.2, 0.2, 0.2, 1.0};
float shininess = 0;

float fogNear = 10;
float fogFar = 100;
float fogAltitudeScale = 10;
float fogThinning = 100;
float4 fogColor = {0.5, 0.5, 0.5, 1.0};

sampler TextureSampler = sampler_state
{
   Texture = <thisTexture>;
};

struct VS_INPUT
{
   float4 Position : POSITION0;
   float2 Texcoord : TEXCOORD0;
   float3 Normal : NORMAL0;
};

struct VS_OUTPUT
{
   float4 Position : POSITION;
   float2 Texcoord : TEXCOORD0;
   float3 Normal : TEXCOORD1;    
   float3 WorldPos : TEXCOORD2;
};
struct PS_INPUT
{
   float4 Position : TEXCOORD4;
   float2 Texcoord : TEXCOORD0;
   float3 Normal : TEXCOORD1;    
   float3 WorldPos : TEXCOORD2;
};

float4 blinn2(
       float3 N,
       float3 L,
       float3 V,
       uniform float4 diffuseColor,
       uniform float4 specularColor,
       uniform float shininess)
{
   float3 H = normalize(V+L);
   float4 lighting = lit(dot(L,N), dot(H,N), shininess);
   return diffuseColor*lighting.y + specularColor*lighting.z;
}


VS_OUTPUT Transform(VS_INPUT Input)
{
   VS_OUTPUT Output;

   Output.WorldPos = mul(Input.Position,World);
   Output.Position = mul(Input.Position, WorldViewProject);
   Output.Texcoord = Input.Texcoord * 500;
   Output.Normal = mul(Input.Normal,World);

   return Output;
}

float4 Texture(PS_INPUT Input) : COLOR0
{
   float4 colorMap = tex2D(TextureSampler, Input.Texcoord.xy);
   float3 N = normalize(Input.Normal);
   float3 V = normalize(EyePosition - Input.WorldPos);
   float3 L = normalize(LightPos - Input.WorldPos);
   
   float4 C = ambient*colorMap;
   
   C += blinn2(N, L, V, colorMap * diffuse, specularColor * colorMap.a, shininess);
   float d = length(Input.WorldPos - EyePosition);
   float l = saturate((d - fogNear) / (fogFar - fogNear) / clamp(Input.Position.y / fogAltitudeScale + 1, 1, fogThinning));
   return lerp(C, fogColor, l);
};

technique TransformTexture
{
   pass P0
   {
       VertexShader = compile vs_1_1 Transform();
       PixelShader  = compile ps_2_0 Texture();
   }
}

And finaly this is the shader used for the sky box, now, you may think, why is he using a sky box when he has such dense fog? Well it is here as an example and this is where I have put the fog calcs into the second pass so you can see how to do it (or rather how I did it)

/////////////////////////////////////////////////////////////
//                                                            //
//    Writen by C.Humphrey                                    //
//    26/07/2007                                                //
//                                                            //
//                                                            //
//    Shader used to render a cube map to an inverted box        //
//    mesh.                                                    //
//                                                            //
// 17/08/2006 Multi pass fog aded.                            //
//                                                            //
//////////////////////////////////////////////////////////////

Texture surfaceTexture;
samplerCUBE TextureSampler = sampler_state
{
   texture = <surfaceTexture> ;
   magfilter = LINEAR;
   minfilter = LINEAR;
   mipfilter = LINEAR;
   AddressU = Mirror;
   AddressV = Mirror;
};

float4x4 World : World;
float4x4 View : View;
float4x4 Projection : Projection;

float3 EyePosition : CameraPosition;

float4 ambient = {0.25, 0.25, 0.25, 1.0};
float4 diffuse = {1.0, 1.0, 1.0, 1.0};
float4 specularColor = {0.2, 0.2, 0.2, 1.0};
float shininess = 10;

float fogNear = 500;
float fogFar = 1000;
float fogAltitudeScale = 0;
float fogThinning = 1;
float4 fogColor = {0.5, 0.5, 0.5, 1.0};

float4 c;

struct VS_INPUT
{
   float4 Position    : POSITION0;
   float3 Normal : NORMAL0;    
};

struct VS_OUTPUT
{
   float4 Position    : POSITION0;
   float3 ViewDirection : TEXCOORD2;
   float3 Normal : TEXCOORD0;
   float4 WorldPos : TEXCOORD1;
};

float4 CubeMapLookup(float3 CubeTexcoord)
{    
   return texCUBE(TextureSampler, CubeTexcoord);
}

VS_OUTPUT Transform(VS_INPUT Input)
{
   float4x4 WorldViewProjection = mul(mul(World, View), Projection);
   float3 ObjectPosition = mul(Input.Position, World);
   
   VS_OUTPUT Output;
   Output.Position    = mul(Input.Position, WorldViewProjection);    
   
   Output.ViewDirection = EyePosition - ObjectPosition;    
   
   Output.WorldPos = mul(Input.Position,World);
   Output.Normal = mul(Input.Normal,World);
   
   return Output;
}

float4 blinn2(
       float3 N,
       float3 L,
       float3 V,
       uniform float4 diffuseColor,
       uniform float4 specularColor,
       uniform float shininess)
{
   float3 H = normalize(V+L);
   float4 lighting = lit(dot(L,N), dot(H,N), shininess);
   return diffuseColor*lighting.y + specularColor*lighting.z;
}

struct PS_INPUT
{    
   float3 ViewDirection : TEXCOORD2;
   float3 Normal : TEXCOORD0;
   float3 WorldPos : TEXCOORD1;
   float4 Position : TEXCOORD3;
};

float4 BasicShader(PS_INPUT Input) : COLOR0
{    
   float3 ViewDirection = normalize(Input.ViewDirection);        
   float4 C = CubeMapLookup(-ViewDirection);
 
   c = C;
   return C;
}
float4 Fog(PS_INPUT Input) : COLOR0
{
   float3 ViewDirection = normalize(Input.ViewDirection);        
   
   float3 N = normalize(Input.Normal);
   float3 V = normalize(EyePosition - Input.WorldPos);
   float3 L = normalize(Input.WorldPos);
   L = normalize(Input.WorldPos);
   
   float4 C = c;
 
   C += blinn2(N, L, V, C * diffuse, specularColor * C.a, shininess);
   float d = fogFar-(fogFar/35);
   float l = saturate((d - fogNear) / (fogFar - fogNear) / clamp(Input.Position.y / fogAltitudeScale + 1, 1, fogThinning));
   return lerp(C, fogColor, l);
}

technique BasicShader
{
   pass P0
   {
       VertexShader = compile vs_2_0 Transform();
       PixelShader  = compile ps_2_0 BasicShader();
   }
   pass P1
   {
       AlphaBlendEnable    = true;
       SrcBlend = SrcAlpha;
       DestBlend = InvSrcAlpha;
       PixelShader  = compile ps_2_0 Fog();
   }
}

Controls
Mouse rotates camera
Arrow Keys translate camera
Esc to exit.

GenericExampleShaderFog.zip

Thanks to Leaf for his example on the XNA UK User Group Without it I would not know how to do it...

Generic XNA - SkyBox

So a sky box, having done the Hazy Mind tutorial and had a play with Riemers tutorials I decided to create my own skybox. I like the way both tutorials do there sky box's but I kind of like cube maps, it means I keep 6 textures in one place, have only one texture variable and so makes my life a little easier when passing textures to my skybox. So my version of a skybox uses a box mesh (the same one from Riemers tutorial) but instead of passing a texture to each side of the box or having to pass multiple textures to the mesh I just pass a single cube map. I then wrote a shader to render the cube map on the skybox mesh.

In this example I also have a basic camera that is a static class, this does not use the GameComponents at all as I want it to be used by all drawable elements in my code, so this class is driven by the game loop directly from in my game class.

So, the code...

SkyBox Class

   public class SkyBox : DrawableGameComponent
   {
       private Model skyboxMesh;
       public Vector3 myPosition;
       public Quaternion myRotation;
       public Vector3 myScale;

       public TextureCube environ;

       Effect shader;

       string modelAsset;
       string shaderAsset;
       string textureAsset;

       ContentManager content;

       public SkyBox(Game game,string modelAsset,string shaderAsset,string textureAsset) : base(game)
       {
           content = new ContentManager(game.Services);

           this.modelAsset = modelAsset;
           this.shaderAsset = shaderAsset;
           this.textureAsset = textureAsset;

           myPosition = new Vector3(0, 0, 0);
           myRotation = new Quaternion(0, 0, 0, 1);
           myScale = new Vector3(55, 55, 55);
       }

       protected override void LoadGraphicsContent(bool loadAllContent)
       {
           if (loadAllContent)
           {
               skyboxMesh = content.Load<Model>(modelAsset);
               shader = content.Load<Effect>(shaderAsset);
               environ = content.Load<TextureCube>(textureAsset);
           }
           base.LoadGraphicsContent(loadAllContent);
       }

       public override void Draw(GameTime gameTime)
       {
           Matrix World = Matrix.CreateScale(myScale) *
                           Matrix.CreateFromQuaternion(myRotation) *
                           Matrix.CreateTranslation(Camera.myPosition);

           shader.Parameters["World"].SetValue(World);
           shader.Parameters["View"].SetValue(Camera.myView);
           shader.Parameters["Projection"].SetValue(Camera.myProjection);
           shader.Parameters["surfaceTexture"].SetValue(environ);

           shader.Parameters["EyePosition"].SetValue(Camera.myPosition);

           for (int pass = 0; pass < shader.CurrentTechnique.Passes.Count; pass++)
           {
               for (int msh = 0; msh < skyboxMesh.Meshes.Count; msh++)
               {
                   ModelMesh mesh = skyboxMesh.Meshes[msh];
                   for (int prt = 0; prt < mesh.MeshParts.Count; prt++)
                       mesh.MeshParts[prt].Effect = shader;
                   mesh.Draw();
               }
           }

           base.Draw(gameTime);
       }        
   }

Camera Class

   public sealed class Camera
   {
       public static Vector3 myPosition;
       public static Vector3 myTarget;
       public static Quaternion myRotation;

       private static Matrix myWorld;
       public static Matrix myView;
       public static Matrix myProjection;
       public static Viewport myViewport;

       private Camera()
       { }

       public static void Initialize()
       {
           myTarget = new Vector3();
           myPosition = new Vector3(0, 0, 0);
           myRotation = new Quaternion(0, 0, 0, 1);
       }

       public  static void Update()
       {
           myWorld = Matrix.Identity;

           myView = Matrix.Invert(Matrix.CreateFromQuaternion(myRotation) *
                                   Matrix.CreateTranslation(myPosition));

           float aspectRatio = myViewport.Width / myViewport.Height;
           myProjection = Matrix.CreatePerspectiveFieldOfView(1, aspectRatio, myViewport.MinDepth, myViewport.MaxDepth);

           myProjection = Matrix.CreatePerspectiveFieldOfView(MathHelper.Pi / 3.0f, (float)myViewport.Width / (float)myViewport.Height, myViewport.MinDepth, myViewport.MaxDepth);
       }
       public static void Rotate(Vector3 axis, float angle)
       {
           axis = Vector3.Transform(axis, Matrix.CreateFromQuaternion(myRotation));
           myRotation = Quaternion.Normalize(Quaternion.CreateFromAxisAngle(axis, angle) * myRotation);

           Update();
       }
       public static void Translate(Vector3 distance)
       {
           myPosition += Vector3.Transform(distance, Matrix.CreateFromQuaternion(myRotation));            
           Update();
       }

       public static void Revolve(Vector3 target, Vector3 axis, float angle)
       {
           Rotate(axis, angle);
           Vector3 revolveAxis = Vector3.Transform(axis, Matrix.CreateFromQuaternion(myRotation));
           Quaternion rotate = Quaternion.CreateFromAxisAngle(revolveAxis, angle);
           myPosition = Vector3.Transform(target - myPosition, Matrix.CreateFromQuaternion(rotate));

           Update();
       }      
   }

SkyBox Shader

//////////////////////////////////////////////////////////////
//                                                            //
//    Writen by C.Humphrey                                    //
//    26/07/2007                                                //
//                                                            //
//                                                            //
//    Shader used to render a cube map to an inverted box        //
//    mesh.                                                    //
//                                                            //
//////////////////////////////////////////////////////////////

Texture surfaceTexture;
samplerCUBE TextureSampler = sampler_state
{
   texture = <surfaceTexture> ;
   magfilter = LINEAR;
   minfilter = LINEAR;
   mipfilter = LINEAR;
   AddressU = Mirror;
   AddressV = Mirror;
};

float4x4 World : World;
float4x4 View : View;
float4x4 Projection : Projection;

float3 EyePosition : CameraPosition;

struct VS_INPUT
{
   float4 Position    : POSITION0;
   float3 Normal : NORMAL0;    
};

struct VS_OUTPUT
{
   float4 Position    : POSITION0;
   float3 ViewDirection : TEXCOORD2;
       
};

float4 CubeMapLookup(float3 CubeTexcoord)
{    
   return texCUBE(TextureSampler, CubeTexcoord);
}

VS_OUTPUT Transform(VS_INPUT Input)
{
   float4x4 WorldViewProjection = mul(mul(World, View), Projection);
   float3 ObjectPosition = mul(Input.Position, World);
   
   VS_OUTPUT Output;
   Output.Position    = mul(Input.Position, WorldViewProjection);    
   
   Output.ViewDirection = EyePosition - ObjectPosition;    
   
   return Output;
}

struct PS_INPUT
{    
   float3 ViewDirection : TEXCOORD2;
};

float4 BasicShader(PS_INPUT Input) : COLOR0
{    
   float3 ViewDirection = normalize(Input.ViewDirection);    
      return CubeMapLookup(-ViewDirection);
}

technique BasicShader
{
   pass P0
   {
       VertexShader = compile vs_2_0 Transform();
       PixelShader  = compile ps_2_0 BasicShader();
   }
}

So the sky box is instantiated like this in the Game1 constructor:

           SkyBox skyBox = new SkyBox(this,"Content/Models/skybox", "Content/Shaders/skybox", "Content/Textures/cubeMap");
           this.Components.Add(skyBox);

The configuration of the camera is a little more detaild. First of all, I want the user to resize the viewport, so I need to wire an event to manage this and update the cameras viewport properties, also, if the user has multiple screens and they drag the game from one window to the next, the camera viewport has to be reset again so this even also needs to be wired. So first off I write my methods to be called by the events.

       /// <summary>
       /// Should the user move the game screen over to another monitor.
       /// </summary>
       /// <param name="sender"></param>
       /// <param name="e"></param>
       void DeviceChanged(object sender, EventArgs e)
       {
           Camera.myViewport = graphics.GraphicsDevice.Viewport;
           Camera.myViewport.MinDepth = 1f;
           Camera.myViewport.MaxDepth = 1000f;
       }

       /// <summary>
       /// Should the game window screen size change.
       /// </summary>
       /// <param name="sender"></param>
       /// <param name="e"></param>
       public void Resize(object sender, EventArgs e)
       {
           Camera.myViewport.Width = Window.ClientBounds.Width;
           Camera.myViewport.Height = Window.ClientBounds.Height;
       }

I now wire these events up in the Game1 constructor.

           Window.ClientSizeChanged += new EventHandler(Resize);
           Window.ScreenDeviceNameChanged += new EventHandler(DeviceChanged);

Now I have those bases covered I need to initialize my camera, this is done in the Initialize method of the Game1 class.

           Camera.Initialize();
           Camera.myViewport = graphics.GraphicsDevice.Viewport;
           Camera.myViewport.MinDepth = 1f;
           Camera.myViewport.MaxDepth = 1000f;

Now all I have to do is update my camera, and yes, you guessed it, this is done in the Update method of the Game2 class.

           Camera.Update();

Controls
Mouse rotates camera.
Esc to exit.

Again, any comments, issues, suggestions or fixes, please comment here.

OOPS! I forgot to add the following method to the SkyBox class, basicly without it if you move the game window to another screen your app will crash as you will get memory violations. Sorry. I have not updated the zip so you will have to do this manualy, source from now on will include this method if needed.

       protected override void UnloadGraphicsContent(bool unloadAllContent)
       {
           content.Unload();
           base.UnloadGraphicsContent(unloadAllContent);
       }

GenericExampleSkyBox.zip

Shader Fog

Have found out how to do fog in the shader so this means that you can now have fog in your XBox 360 games as well as your Windows based games.

As usual it is a matter of adding the right semantic and setting the correct renderstate in the shader.

So, the code.

Shader Model 1.1 - 2
In your Shader's vertex return structure, add the following

float Fog : FOG;

In your vertex shader set the fog you require:

Output.Fog = 1.0f - ( length( Input.Position - EyePosition) / 50.0f);

Note: This is an example you can generate this how ever you need to.

Now all you have to do is set the render state for fog, so in the top of your pass add this

FOGENABLE = (3);
FOGCOLOR = (float4(.5,.5,.5,1));

Where 3 is Linear fog and float4(.5,.5,.5,1) would be the color gray.

Shader Model 3
To get fog working on SM 3 and/or the XBox 360 is a little different

Remove ALL state settings in the technique.

Swap the FOG simantic for a TEXCOORD.

As the FOGCOLOR state has been removed, you need to
   calulate this in the shader per vertex lerp between the
   calculated color and the fog color based on the FOG
   TEXCOORD

For Example:

Out.Color = lerp(g_FogColor, color * ((In.Diffuse * g_MaterialDiffuseColor) * diffuse + g_MaterialAmbientColor), In.Fog);

Thanks to Leaf at XNA UK User Group and Jon Watte for your help with this I am sure this will help many others in there XNA development. Jon's shader also has the ability to specify the height of the fog and so giving a much richer fog effect, nice...

If you have any interest in the discussions we had then take a look here or the comments on this post.

Leaf has also put up an example of Jon's shader in action and you can find that here.

Engine Design - Terrain (Bump/Normal Mapping)

Well, looks like my post on fire is on hold for now. So here is my bump/normal mapped terrain shaders and the modifications I made to my existing terrain object.

Changes to the Terrain Class
First thing I had to do was figure out how to add tangents to the terrain Vertex Element, so I put a post on the XNA Creators Club (no laughing at my game tag, I have been trying to change it but to no avail..) and Shawn Hargreaves replied with the solution. I think I may have applied it too literally as there is another post on there pointing to an article on ziggyware describing how to generate tangents and it is quite a lump of code! Also, I have tested my stuff with the tangent elements removed...and it still seems to work, odd. But what the hell I am new to all this and I got the bump mapping working and that is all I am bothered about. Though, if you can point me in the direction for creating the tangent data correctly then please post a comment :)

So, the code changes. I added a tangent vector3 to the Vertex Element.

       protected struct VertexMultitextured
       {
           public Vector3 Position;
           public Vector3 Normal;            
           public Vector4 TextureCoordinate;
           public Vector4 TexWeights;
           public Vector3 Tangent;

           public static int SizeInBytes = (3 + 3 + 3 + 4 + 4) * 4;
           public static VertexElement[] VertexElements = new VertexElement[]
            {
                new VertexElement( 0, 0, VertexElementFormat.Vector3, VertexElementMethod.Default, VertexElementUsage.Position, 0 ),
                new VertexElement( 0, sizeof(float) * 3, VertexElementFormat.Vector3, VertexElementMethod.Default, VertexElementUsage.Normal, 0 ),
                new VertexElement( 0, sizeof(float) * 6, VertexElementFormat.Vector4, VertexElementMethod.Default, VertexElementUsage.TextureCoordinate, 0 ),
                new VertexElement( 0, sizeof(float) * 10, VertexElementFormat.Vector4, VertexElementMethod.Default, VertexElementUsage.TextureCoordinate, 1 ),
                new VertexElement( 0, sizeof(float) * 14, VertexElementFormat.Vector3, VertexElementMethod.Default, VertexElementUsage.Tangent, 0 ),
            };
       }

Once this was added I had to calcualte the tangent data per vertex. So in my BuildTerrain method of the class I added a line to the loop that calulates the vertex normal. (second loop in the method)

           for (int x = 1; x < myWidth - 1; x++)
           {
               for (int y = 1; y < myHeight - 1; y++)
               {
                   Vector3 normX = new Vector3((myVertices[x - 1 + y * myWidth].Position.Y - myVertices[x + 1 + y * myWidth].Position.Y) / 2, 0, 1);
                   Vector3 normY = new Vector3(0, 1, (myVertices[x + (y - 1) * myWidth].Position.Y - myVertices[x + (y + 1) * myWidth].Position.Y) / 2);
                   myVertices[x + y * myWidth].Normal = normX + normY;
                   myVertices[x + y * myWidth].Normal.Normalize();

                   myVertices[x + y * myWidth].Tangent = myVertices[x - 1 + y * myWidth].Position - myVertices[x + 1 + y * myWidth].Position;                    
               }
           }

Now that was all set up I needed to get the normals passed to the class and store them. So I have added these fields and properties.

   private bool bumpOn;
   private string[] myBumpMapAssets;

   public bool BumpOn
   {
      get { return bumpOn; }
      set { bumpOn = value; }
   }

Now I altered the constructor to handle the new texture feed.

       public RCTerrain(string[] textureAssets,string[] bumpAssets,string heightAsset,string name):base(name)
       {          
           myHeightAsset = heightAsset;

           myAssets = new string[textureAssets.Length];
           for(int ass=0;ass<textureAssets.Length;ass++)
               myAssets[ass] = textureAssets[ass];

           myBumpMapAssets = new string[bumpAssets.Length];
           for (int ass = 0; ass < bumpAssets.Length; ass++)
               myBumpMapAssets[ass] = bumpAssets[ass];

           bumpOn = true;
       }

And added this loop to the LoadGraphicsContent method

           bumpMaps = new Texture2D[myBumpMapAssets.Length];
           for (int ass = 0; ass < myBumpMapAssets.Length; ass++)
               bumpMaps[ass] = myLoader.Load<Texture2D>(myBumpMapAssets[ass]);

Will all that set up I now altered the Render method to use the new textures

           if (effect.Parameters["bumpOn"] != null)
               effect.Parameters["bumpOn"].SetValue(bumpOn);

           if (effect.Parameters["tileSizeMod"] != null)
               effect.Parameters["tileSizeMod"].SetValue(1f);

           if (effect.Parameters["BumpMap0"] != null)
               effect.Parameters["BumpMap0"].SetValue(bumpMaps[0]);
           if (effect.Parameters["BumpMap1"] != null)
               effect.Parameters["BumpMap1"].SetValue(bumpMaps[1]);
           if (effect.Parameters["BumpMap2"] != null)
               effect.Parameters["BumpMap2"].SetValue(bumpMaps[2]);
           if (effect.Parameters["BumpMap3"] != null)
               effect.Parameters["BumpMap3"].SetValue(bumpMaps[3]);

Shaders
Now to the shaders, the first shader was Reimers origional terrain shader the only change I have really made is to add the bump/normal mapping. The second shader is mine, I have put a few more comments in mine so it should be a bit more readable.

Reimers Shader modified by me

//////////////////////////////////////////////////////////////////
//                                                                //
//    This terrain shader was origionaly written by                //
//  Reimer (http://www.riemers.net/)                            //
//  I have modified it so it now had a bump map effect            //
//                                                                //
//  26/06/2007 C.Humphrey (http://randomchaosuk.blogspot.com/)    //
//                                                                //
//////////////////////////////////////////////////////////////////

struct MultiTexVertexToPixel
{
   float4 Position         : POSITION;    
   float4 Color            : COLOR0;
   float3 Normal            : TEXCOORD0;
   float4 TextureCoords    : TEXCOORD1;
   float4 LightDirection    : TEXCOORD2;
   float4 TextureWeights    : TEXCOORD3;
   float    Depth            : TEXCOORD4;
   float shade : TEXCOORD5;
   float3 lView : TEXCOORD6;
};


struct MultiTexPixelToFrame
{
   float4 Color : COLOR0;
};

//------- Constants --------
float4x4 World : World;
float4x4 wvp : WorldViewProjection;
float3 LightPosition : LightDirection;
float Ambient : Ambient;
float3 EyePosition : CAMERAPOSITION;

Texture SandTexture;
sampler SandTextureSampler = sampler_state
{
   texture = <SandTexture> ;
   magfilter = LINEAR;
   minfilter = LINEAR;
   mipfilter=LINEAR;
   AddressU = mirror;
   AddressV = mirror;
};

Texture GrassTexture;
sampler GrassTextureSampler = sampler_state
{
   texture = <GrassTexture> ;
   magfilter = LINEAR;
   minfilter = LINEAR;
   mipfilter=LINEAR;
   AddressU = mirror;
   AddressV = mirror;
};

Texture RockTexture;
sampler RockTextureSampler = sampler_state
{
   texture = <RockTexture> ;
   magfilter = LINEAR;
   minfilter = LINEAR;
   mipfilter=LINEAR;
   AddressU = mirror;
   AddressV = mirror;
};

Texture SnowTexture;
sampler SnowTextureSampler = sampler_state
{
   texture = <SnowTexture>;
   magfilter = LINEAR;
   minfilter = LINEAR;
   mipfilter=LINEAR;
   AddressU = mirror;
   AddressV = mirror;
};

texture BumpMap0;
sampler BumpMap0Sampler = sampler_state
{
   Texture = <BumpMap0>;
   MinFilter = Linear;
   MagFilter = Linear;
   MipFilter = Linear;
   AddressU = mirror;
   AddressV = mirror;
};
texture BumpMap1;
sampler BumpMap1Sampler = sampler_state
{
   Texture = <BumpMap1>;
   MinFilter = Linear;
   MagFilter = Linear;
   MipFilter = Linear;
   AddressU = mirror;
   AddressV = mirror;
};

texture BumpMap2;
sampler BumpMap2Sampler = sampler_state
{
   Texture = <BumpMap2>;
   MinFilter = Linear;
   MagFilter = Linear;
   MipFilter = Linear;
   AddressU = mirror;
   AddressV = mirror;
};

texture BumpMap3;
sampler BumpMap3Sampler = sampler_state
{
   Texture = <BumpMap3>;
   MinFilter = Linear;
   MagFilter = Linear;
   MipFilter = Linear;
   AddressU = mirror;
   AddressV = mirror;
};

MultiTexVertexToPixel MultiTexturedVS( float4 inPos : POSITION, float3 inNormal: NORMAL, float4 inTexCoords: TEXCOORD0, float4 inTexWeights: TEXCOORD1, float3 Tangent : TANGENT)
{
   MultiTexVertexToPixel Output = (MultiTexVertexToPixel)0;
   
   Output.Position = mul(inPos, wvp);
   Output.Normal = mul(normalize(inNormal), World);
   Output.TextureCoords = inTexCoords;
   Output.LightDirection.xyz = LightPosition;
   Output.LightDirection.w = 1;
   Output.TextureWeights = inTexWeights;
   Output.Depth = Output.Position.y;
   Output.shade = saturate(saturate(dot(Output.Normal, normalize(Output.LightDirection))) + Ambient);    
   
   float3x3 worldToTangentSpace;
   worldToTangentSpace[0] = mul(Tangent,World);
   worldToTangentSpace[1] = mul(cross(Tangent,inNormal),World);
   worldToTangentSpace[2] = mul(inNormal,World);
   
   Output.lView = mul(worldToTangentSpace,EyePosition - Output.Position);    
   
   return Output;    
}

MultiTexPixelToFrame MultiTexturedPS(MultiTexVertexToPixel PSIn)
{
   MultiTexPixelToFrame Output = (MultiTexPixelToFrame)0;
 
   float blendDistance = 30;
   float blendWidth = 50;
   float blendFactor = clamp((PSIn.Depth-blendDistance)/blendWidth, 0, 1);

   float4 farColor = 0;
   farColor = tex2D(SandTextureSampler, PSIn.TextureCoords)*PSIn.TextureWeights.x;
   farColor += tex2D(GrassTextureSampler, PSIn.TextureCoords)*PSIn.TextureWeights.y;
   farColor += tex2D(RockTextureSampler, PSIn.TextureCoords)*PSIn.TextureWeights.z;
   farColor += tex2D(SnowTextureSampler, PSIn.TextureCoords)*PSIn.TextureWeights.w;

   float4 nearColor;
   float2 nearTextureCoords = PSIn.TextureCoords*3;
   nearColor = tex2D(SandTextureSampler, nearTextureCoords)*PSIn.TextureWeights.x;
   nearColor += tex2D(GrassTextureSampler, nearTextureCoords)*PSIn.TextureWeights.y;
   nearColor += tex2D(RockTextureSampler, nearTextureCoords)*PSIn.TextureWeights.z;
   nearColor += tex2D(SnowTextureSampler, nearTextureCoords)*PSIn.TextureWeights.w;
 
   float lightingFactor = saturate(saturate(dot(PSIn.Normal, normalize(PSIn.LightDirection))) + Ambient);      
   
   float4 LightDir = normalize(PSIn.LightDirection);
   float3 ViewDir = normalize(PSIn.lView);

   float3 Normal;
   Normal = tex2D(BumpMap0Sampler,nearTextureCoords)*PSIn.TextureWeights.x;
   Normal += tex2D(BumpMap1Sampler,nearTextureCoords)*PSIn.TextureWeights.y;
   Normal += tex2D(BumpMap2Sampler,nearTextureCoords)*PSIn.TextureWeights.z;
   Normal += tex2D(BumpMap3Sampler,nearTextureCoords)*PSIn.TextureWeights.w;
   
   Normal = 2 * Normal - 1.0;    
   float4 Color = nearColor + farColor;
   
   float Diffuse = saturate(dot(Normal,LightDir));    
   float Reflect = normalize(2 * Diffuse * Normal - LightDir);    
   float Specular = min(pow(saturate(dot(Reflect,ViewDir)),3),Color.w);
   
   Output.Color = (0.2 * ((farColor*blendFactor + nearColor*(1-blendFactor))*4) * (Diffuse + Specular)) * (PSIn.shade*3);    
   
   return Output;
}

technique MultiTextured
{
   pass Pass0
   {
       VertexShader = compile vs_2_0 MultiTexturedVS();
       PixelShader = compile ps_2_0 MultiTexturedPS();
   }    
}

My Shader

//////////////////////////////////////////////////////////////////////////////
//                                                                            //
//    NemoKradBumpTerrain.fx Terrain shader by C.Humphrey 02/05/2007          //
//                                                                            //
//    This shader is based on terrain shaders by Riemer and Frank Luna.       //
//  Riemer: http://www.riemers.net                                            //
//  Frank Luna: http://www.moon-labs.com                                    //
//                                                                            //
//    http://randomchaos.co.uk                                                //
//    http://randomchaosuk.blogspot.com                                        //
//                                                                            //
// 25/06/2007 - Adde bumpmap functionlaity                                    //
//                                                                            //
//////////////////////////////////////////////////////////////////////////////

float4x4 wvp : WorldViewProjection;
float4x4 world : World;
float3 LightPosition : LightDirection;
float3 EyePosition : CAMERAPOSITION;

// Do we want to use bump map feature?
bool bumpOn = true;

// Texture size moifier 1 = no change.
float tileSizeMod = 1;

// Terrain Textures.
texture  LayerMap0;
texture  LayerMap1;
texture  LayerMap2;
texture  LayerMap3;

// Terrain Normals for above texture.
texture BumpMap0;
texture BumpMap1;
texture BumpMap2;
texture BumpMap3;

// Normal samplers
sampler BumpMap0Sampler = sampler_state
{
   Texture = <BumpMap0>;
   MinFilter = Linear;
   MagFilter = Linear;
   MipFilter = Linear;
   AddressU = mirror;
   AddressV = mirror;
};

sampler BumpMap1Sampler = sampler_state
{
   Texture = <BumpMap1>;
   MinFilter = Linear;
   MagFilter = Linear;
   MipFilter = Linear;
   AddressU = mirror;
   AddressV = mirror;
};

sampler BumpMap2Sampler = sampler_state
{
   Texture = <BumpMap2>;
   MinFilter = Linear;
   MagFilter = Linear;
   MipFilter = Linear;
   AddressU = mirror;
   AddressV = mirror;
};

sampler BumpMap3Sampler = sampler_state
{
   Texture = <BumpMap3>;
   MinFilter = Linear;
   MagFilter = Linear;
   MipFilter = Linear;
   AddressU = mirror;
   AddressV = mirror;
};

// Texture Samplers
sampler LayerMap0Sampler = sampler_state
{
   Texture   = <LayerMap0>;
   MinFilter = LINEAR;
   MagFilter = LINEAR;
   MipFilter = LINEAR;
   AddressU  = WRAP;
   AddressV  = WRAP;
};

sampler LayerMap1Sampler = sampler_state
{
   Texture   = <LayerMap1>;
   MinFilter = LINEAR;
   MagFilter = LINEAR;
   MipFilter = LINEAR;
   AddressU  = WRAP;
   AddressV  = WRAP;
};

sampler LayerMap2Sampler = sampler_state
{
   Texture   = <LayerMap2>;
   MinFilter = LINEAR;
   MagFilter = LINEAR;
   MipFilter = LINEAR;
   AddressU  = WRAP;
   AddressV  = WRAP;
};
sampler LayerMap3Sampler = sampler_state
{
   Texture   = <LayerMap3>;
   MinFilter = LINEAR;
   MagFilter = LINEAR;
   MipFilter = LINEAR;
   AddressU  = WRAP;
   AddressV  = WRAP;
};

// Vertex Shader input structure.
struct VS_INPUT
{
   float4 posL         : POSITION0;
   float3 normalL      : NORMAL0;
   float4 tiledTexC    : TEXCOORD0;
   float4 TextureWeights : TEXCOORD1;
   float3 Tangent : TANGENT;
};

// Vertex Shader output structure/Pixel Shaer input structure
struct VS_OUTPUT
{
   float4 posH         : POSITION0;
   float  shade        : TEXCOORD0;
   float4 tiledTexC    : TEXCOORD1;  
   float4 TextureWeights : TEXCOORD2;    
   float4 Light : TEXCOORD3;
   float3 lView : TEXCOORD4;
};

// Vetex Shader
VS_OUTPUT BumpVS(VS_INPUT input)
{
   // Clean the output structure.
   VS_OUTPUT Out = (VS_OUTPUT)0;
       
   // Calculate tangent space.
   float3x3 worldToTangentSpace;
   worldToTangentSpace[0] = mul(input.Tangent,world);
   worldToTangentSpace[1] = mul(cross(input.Tangent,input.normalL),world);
   worldToTangentSpace[2] = mul(input.normalL,world);    
   
   // Get world pos for texture and normal.
   float4 PosWorld = mul(input.posL,world);    
   
   // Get light position.
   Out.Light.xyz = LightPosition;
   Out.Light.w = 1;
   
   // Set position for pixel shader
   Out.posH  = mul(input.posL, wvp);        
   
   // Set lighting.
   Out.shade = saturate(saturate(dot(input.normalL, normalize(LightPosition))));    
   
   // Set view direction for normals.
   Out.lView = mul(worldToTangentSpace,EyePosition - Out.posH);    
   
   // Set tile TexCoord.
   Out.tiledTexC = input.tiledTexC * tileSizeMod;
       
   // Set Texture weight.
   Out.TextureWeights = input.TextureWeights;    
   
   return Out;
}
// Output to screen.
struct PixelToFrame
{
   float4 Color : COLOR0;
};

// Pixel shader.
PixelToFrame BumpPS(VS_OUTPUT input) : COLOR
{
   // Clean output structure.
   PixelToFrame Out = (PixelToFrame)0;    
   
   // Get pixel color.
   float4 Col = tex2D(LayerMap0Sampler, input.tiledTexC)*input.TextureWeights.x;
   Col += tex2D(LayerMap1Sampler, input.tiledTexC)*input.TextureWeights.y;
   Col += tex2D(LayerMap2Sampler, input.tiledTexC)*input.TextureWeights.z;
   Col += tex2D(LayerMap3Sampler, input.tiledTexC)*input.TextureWeights.w;
   
   // Set light directon amd view direction.
   float4 LightDir = normalize(input.Light);
   float3 ViewDir = normalize(input.lView);
   
   // Get prominent normal.    
   float2 nearTextureCoords = input.tiledTexC*3;
   float3 Normal;
   Normal = tex2D(BumpMap0Sampler,nearTextureCoords)*input.TextureWeights.x;
   Normal += tex2D(BumpMap1Sampler,nearTextureCoords)*input.TextureWeights.y;
   Normal += tex2D(BumpMap2Sampler,nearTextureCoords)*input.TextureWeights.z;
   Normal += tex2D(BumpMap3Sampler,nearTextureCoords)*input.TextureWeights.w;    
   Normal = 2 * Normal - 1.0;    
       
   // Set diffuse, reflection and specular effect for Normal.
   float Diffuse = saturate(dot(Normal,LightDir));    
   float Reflect = normalize(2 * Diffuse * Normal - LightDir);
   float Specular = min(pow(saturate(dot(Reflect,ViewDir)),3),Col.w);    
   
   float4 final;
   
   // Do color calculation depending if bump feature is on or off.
   if(bumpOn)
       final = (0.2 * Col * (Diffuse + Specular)) * (input.shade * 12);
   else
       final = Col * input.shade;

   Out.Color = final;
   
   return Out;
}

technique Terrain_MultiTex
{
   pass P0
   {
       vertexShader = compile vs_2_0 BumpVS();
       pixelShader  = compile ps_2_0 BumpPS();
   }    
}

Screen Shots
Right here are a number of screen shots from different angles so you can see how the two shaders render, I have also put up my FPS counter so you can see the performance.
In each set I do my best to get the same camera position. Oh and I don't want you to think that Reimers shader is the worst of the two, my shader is quicker because it does the job in a much cruder way. I guess you have to go for speed or beuty, unless your machine is supper fast.

Riemers with Bump/Normal mapping Pic 1

My shader Pic 1

Riemers with Bump/Normal mapping Pic2

My shader Pic 2

Riemers with Bump/Normal mapping Pic 3

My shader Pic 3

Riemers with Bump/Normal mapping Pic 4

My shader Pic 4

Terrain Up Close
Here are images of the terrain up close. I think you will agree using Remiers terrain render is better looking, well especialy now it has bump mapping :)

Riemers with Bump/Normal mapping Sand

My shader Sand

Riemers with Bump/Normal mapping Grass

My shader Grass

Riemers with Bump/Normal mapping Stone

My shader Stone

Riemers with Bump/Normal mapping Snow

My shader Snow


Textures and Normals
Here are the textures used in my examples, they are not the origional DDS files as this blog wont host them, all you have to do is go to Reimers turorial, and you can down load the textures there, all you have to do then is use PhotoShop and NVIDIAs Normal tool to generate the normal. If I have time I will put a zip up on my server and link to it from here.

Sand & Normal

Grass & Normal

Stone & Normal

Snow & Normal

By all means please, if you optomize these shaders ot even the terrain class I would love to know what you did. I am planning on doing terrain culling in the future and if I ever get time to get my head into it ROAM terrain.

PHEW! That has to be my biggest post!