3D系列4.19 渐变的天空球
现在我们已经获得了一个云层贴图，让我们编写一个technique将贴图显示在天空球上，这会产生一个渐变的天空球。
这个technique很简单。如果看一下室外，大气层的顶部的颜色要比水平面深，让我们在HLSL中实现这个效果。
通常，我们会首先定义顶点着色器和像素着色器的输出结构：
//------- Technique: SkyDome --------
struct SDVertexToPixel
{
float4 Position : POSITION;
float2 TextureCoords : TEXCOORD0;
float4 ObjectPosition : TEXCOORD1;
};
struct SDPixelToFrame
{
float4 Color : COLOR0;
};
顶点着色器需要将纹理坐标和每个顶点的位置传递到像素着色器中。顶点的位置总是保持不变的，无论对象（本例中是天空球）是否旋转、移动或缩放。这让我们可以在像素着色器中定义一个固定的渐变。
下面是顶点着色器：
SDVertexToPixel SkyDomeVS( float4 inPos : POSITION, float2 inTexCoords: TEXCOORD0)
{
SDVertexToPixel Output = (SDVertexToPixel)0;
float4x4 preViewProjection = mul (xView, xProjection);
float4x4 preWorldViewProjection = mul (xWorld, preViewProjection);
Output.Position = mul(inPos, preWorldViewProjection);
Output.TextureCoords = inTexCoords;
Output. ObjectPosition = inPos;
return Output;
}
你可以看到初始位置和纹理坐标立即被传递到ObjectPos和TextureCoords中。因为天空盒是一个3D模型，需要被转换到2D屏幕坐标，我们通常需要WorldViewProjection
矩阵转换3D位置并将结果传递到Output.Position中。
像素着色器很简单，我本希望最后一章会更难点，但实际上却不是：
SDPixelToFrame SkyDomePS(SDVertexToPixel PSIn)
{
SDPixelToFrame Output = (SDPixelToFrame)0;
float4 topColor = float4(0.3f, 0.3f, 0.8f, 1);
float4 bottomColor = 1;
float4 baseColor = lerp(bottomColor, topColor, saturate((PSIn. ObjectPosition.y)/0.4f));
float4 cloudValue = tex2D(TextureSampler, PSIn.TextureCoords).r;
Output.Color = lerp(baseColor,1, cloudValue);
return Output;
}
你定义了2个颜色：一个是天空顶部的暗蓝色和水平面的白色。然后，基于天空球的当前像素对这两个颜色进行插值。天空球的最高点高度为Y=0.5，所以高于0.4的所有像素为暗蓝色。低于0.4的所有像素的颜色为暗蓝色和白色间的插值。最后，我们从天空纹理的对应像素中查询值，使用这个值对天空颜色和白色进行插值，将云添加到天空球中。
好了！下面只需添加technique定义：
technique SkyDome
{
pass Pass0
{
VertexShader = compile vs_1_1 SkyDomeVS();
PixelShader = compile ps_2_0 SkyDomePS();
}
}
这样就做好了改变DrawSkydome方法的准备，它现在还是使用Textured
technique，我们无需改变太多，事实上，我们只需改变使用的technique名称。
currentEffect.CurrentTechnique = currentEffect.Techniques["SkyDome"];
运行代码后，你会看到系列4的最终效果。
我们在系列4中学习了第一人称相机，多纹理地形，移动的水面，billboard和perlin噪点，我希望你能学到很多东西！
最终的XNA代码如下，红色代码为相对于上一章改变的部分：
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 XNAseries4
...{
public struct VertexMultitextured
...{
public Vector3 Position;
public Vector3 Normal;
public Vector4 TextureCoordinate;
public Vector4 TexWeights;
public static int SizeInBytes = (3 + 3 + 4 + 4) * sizeof(float);
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 ),
};
}
public class Game1 : Microsoft.Xna.Framework.Game
...{
GraphicsDeviceManager graphics;
GraphicsDevice device;
int terrainWidth;
int terrainLength;
float[,] heightData;
VertexBuffer terrainVertexBuffer;
IndexBuffer terrainIndexBuffer;
VertexDeclaration terrainVertexDeclaration;
VertexBuffer waterVertexBuffer;
VertexDeclaration waterVertexDeclaration;
VertexBuffer treeVertexBuffer;
VertexDeclaration treeVertexDeclaration;
Effect effect;
Effect bbEffect;
Matrix viewMatrix;
Matrix projectionMatrix;
Matrix reflectionViewMatrix;
Vector3 cameraPosition = new Vector3(130, 30, -50);
float leftrightRot = MathHelper.PiOver2;
float updownRot = -MathHelper.Pi / 10.0f;
const float rotationSpeed = 0.3f;
const float moveSpeed = 30.0f;
MouseState originalMouseState;
Texture2D grassTexture;
Texture2D sandTexture;
Texture2D rockTexture;
Texture2D snowTexture;
Texture2D cloudMap;
Texture2D waterBumpMap;
Texture2D treeTexture;
Texture2D treeMap;
Model skyDome;
const float waterHeight = 5.0f;
RenderTarget2D refractionRenderTarget;
Texture2D refractionMap;
RenderTarget2D reflectionRenderTarget;
Texture2D reflectionMap;
RenderTarget2D cloudsRenderTarget;
Texture2D cloudStaticMap;
VertexPositionTexture[] fullScreenVertices;
VertexDeclaration fullScreenVertexDeclaration;
Vector3 windDirection = new Vector3(0, 0, 1);
public Game1()
...{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
}
protected override void Initialize()
...{
graphics.PreferredBackBufferWidth = 500;
graphics.PreferredBackBufferHeight = 500;
graphics.ApplyChanges();
Window.Title = "Riemer's XNA Tutorials -- Series 4";
base.Initialize();
}
protected override void LoadContent()
...{
device = GraphicsDevice;
effect = Content.Load<Effect> ("Series4Effects");
bbEffect = Content.Load<Effect> ("bbEffect"); UpdateViewMatrix();
projectionMatrix = Matrix.CreatePerspectiveFieldOfView(MathHelper.PiOver4, device.Viewport.AspectRatio, 0.3f, 1000.0f);
Mouse.SetPosition(device.Viewport.Width / 2, device.Viewport.Height / 2);
originalMouseState = Mouse.GetState();
skyDome = Content.Load<Model> ("dome"); skyDome.Meshes[0].MeshParts[0].Effect = effect.Clone(device);
PresentationParameters pp = device.PresentationParameters;
refractionRenderTarget = new RenderTarget2D(device, pp.BackBufferWidth, pp.BackBufferHeight, 1, device.DisplayMode.Format);
reflectionRenderTarget = new RenderTarget2D(device, pp.BackBufferWidth, pp.BackBufferHeight, 1, device.DisplayMode.Format);
cloudsRenderTarget = new RenderTarget2D(device, pp.BackBufferWidth, pp.BackBufferHeight, 1, device.DisplayMode.Format);
LoadVertices();
LoadTextures();
}
private void LoadVertices()
...{
Texture2D heightMap = Content.Load<Texture2D> ("heightmap"); LoadHeightData(heightMap);
VertexMultitextured[] terrainVertices = SetUpTerrainVertices();
int[] terrainIndices = SetUpTerrainIndices();
terrainVertices = CalculateNormals(terrainVertices, terrainIndices);
CopyToTerrainBuffers(terrainVertices, terrainIndices);
terrainVertexDeclaration = new VertexDeclaration(device, VertexMultitextured.VertexElements);
SetUpWaterVertices();
waterVertexDeclaration = new VertexDeclaration(device, VertexPositionTexture.VertexElements);
Texture2D treeMap = Content.Load<Texture2D> ("treeMap");
List<Vector3> treeList = GenerateTreePositions(treeMap, terrainVertices); CreateBillboardVerticesFromList(treeList);
fullScreenVertices = SetUpFullscreenVertices();
fullScreenVertexDeclaration = new VertexDeclaration(device, VertexPositionTexture.VertexElements);
}
private void LoadTextures()
...{
grassTexture = Content.Load<Texture2D> ("grass");
sandTexture = Content.Load<Texture2D> ("sand");
rockTexture = Content.Load<Texture2D> ("rock");
snowTexture = Content.Load<Texture2D> ("snow");
cloudMap = Content.Load<Texture2D> ("cloudMap");
waterBumpMap = Content.Load<Texture2D> ("waterbump");
treeTexture = Content.Load<Texture2D> ("tree");
treeMap = Content.Load<Texture2D> ("treeMap"); cloudStaticMap = CreateStaticMap(32);
}
private void LoadHeightData(Texture2D heightMap)
...{
float minimumHeight = float.MaxValue;
float maximumHeight = float.MinValue;
terrainWidth = heightMap.Width;
terrainLength = heightMap.Height;
Color[] heightMapColors = new Color[terrainWidth * terrainLength];
heightMap.GetData(heightMapColors);
heightData = new float[terrainWidth, terrainLength];
for (int x = 0; x < terrainWidth; x++)
for (int y = 0; y < terrainLength; y++)
...{
heightData[x, y] = heightMapColors[x + y * terrainWidth].R;
if (heightData[x, y] < minimumHeight) minimumHeight = heightData[x, y];
if (heightData[x, y] > maximumHeight) maximumHeight = heightData[x, y];
}
for (int x = 0; x < terrainWidth; x++)
for (int y = 0; y < terrainLength; y++)
heightData[x, y] = (heightData[x, y] - minimumHeight) / (maximumHeight - minimumHeight) * 30.0f;
}
private VertexMultitextured[] SetUpTerrainVertices()
...{
VertexMultitextured[] terrainVertices = new VertexMultitextured[terrainWidth * terrainLength];
for (int x = 0; x < terrainWidth; x++)
...{
for (int y = 0; y < terrainLength; y++)
...{
terrainVertices[x + y * terrainWidth].Position = new Vector3(x, heightData[x, y], -y);
terrainVertices[x + y * terrainWidth].TextureCoordinate.X = (float)x / 30.0f;
terrainVertices[x + y * terrainWidth].TextureCoordinate.Y = (float)y / 30.0f;
terrainVertices[x + y * terrainWidth].TexWeights.X = MathHelper.Clamp(1.0f - Math.Abs(heightData[x, y] - 0) / 8.0f, 0, 1);
terrainVertices[x + y * terrainWidth].TexWeights.Y = MathHelper.Clamp(1.0f - Math.Abs(heightData[x, y] - 12) / 6.0f, 0, 1);
terrainVertices[x + y * terrainWidth].TexWeights.Z = MathHelper.Clamp(1.0f - Math.Abs(heightData[x, y] - 20) / 6.0f, 0, 1);
terrainVertices[x + y * terrainWidth].TexWeights.W = MathHelper.Clamp(1.0f - Math.Abs(heightData[x, y] - 30) / 6.0f, 0, 1);
float total = terrainVertices[x + y * terrainWidth].TexWeights.X;
total += terrainVertices[x + y * terrainWidth].TexWeights.Y;
total += terrainVertices[x + y * terrainWidth].TexWeights.Z;
total += terrainVertices[x + y * terrainWidth].TexWeights.W;
terrainVertices[x + y * terrainWidth].TexWeights.X /= total;
terrainVertices[x + y * terrainWidth].TexWeights.Y /= total;
terrainVertices[x + y * terrainWidth].TexWeights.Z /= total;
terrainVertices[x + y * terrainWidth].TexWeights.W /= total;
}
}
return terrainVertices;
}
private int[] SetUpTerrainIndices()
...{
int[] indices = new int[(terrainWidth - 1) * (terrainLength - 1) * 6];
int counter = 0;
for (int y = 0; y < terrainLength - 1; y++)
...{
for (int x = 0; x < terrainWidth - 1; x++)
...{
int lowerLeft = x + y * terrainWidth;
int lowerRight = (x + 1) + y * terrainWidth;
int topLeft = x + (y + 1) * terrainWidth;
int topRight = (x + 1) + (y + 1) * terrainWidth;
indices[counter++] = topLeft;
indices[counter++] = lowerRight;
indices[counter++] = lowerLeft;
indices[counter++] = topLeft;
indices[counter++] = topRight;
indices[counter++] = lowerRight;
}
}
return indices;
}
private VertexMultitextured[] CalculateNormals(VertexMultitextured[] vertices, int[] indices)
...{
for (int i = 0; i < vertices.Length; i++)
vertices[i].Normal = new Vector3(0, 0, 0);
for (int i = 0; i < indices.Length / 3; i++)
...{
int index1 = indices[i * 3];
int index2 = indices[i * 3 + 1];
int index3 = indices[i * 3 + 2];
Vector3 side1 = vertices[index1].Position - vertices[index3].Position;
Vector3 side2 = vertices[index1].Position - vertices[index2].Position;
Vector3 normal = Vector3.Cross(side1, side2);
vertices[index1].Normal += normal;
vertices[index2].Normal += normal;
vertices[index3].Normal += normal;
}
for (int i = 0; i < vertices.Length; i++)
vertices[i].Normal.Normalize();
return vertices;
}
private void CopyToTerrainBuffers(VertexMultitextured[] vertices, int[] indices)
...{
terrainVertexBuffer = new VertexBuffer(device, vertices.Length * VertexMultitextured.SizeInBytes, BufferUsage.WriteOnly);
terrainVertexBuffer.SetData(vertices);
terrainIndexBuffer = new IndexBuffer(device, typeof(int), indices.Length, BufferUsage.WriteOnly);
terrainIndexBuffer.SetData(indices);
}
private void SetUpWaterVertices()
...{
VertexPositionTexture[] waterVertices = new VertexPositionTexture[6];
waterVertices[0] = new VertexPositionTexture(new Vector3(0, waterHeight, 0), new Vector2(0, 1));
waterVertices[2] = new VertexPositionTexture(new Vector3(terrainWidth, waterHeight, -terrainLength), new Vector2(1, 0));
waterVertices[1] = new VertexPositionTexture(new Vector3(0, waterHeight, -terrainLength), new Vector2(0, 0));
waterVertices[3] = new VertexPositionTexture(new Vector3(0, waterHeight, 0), new Vector2(0, 1));
waterVertices[5] = new VertexPositionTexture(new Vector3(terrainWidth, waterHeight, 0), new Vector2(1, 1));
waterVertices[4] = new VertexPositionTexture(new Vector3(terrainWidth, waterHeight, -terrainLength), new Vector2(1, 0));
waterVertexBuffer = new VertexBuffer(device, waterVertices.Length * VertexPositionTexture.SizeInBytes, BufferUsage.WriteOnly);
waterVertexBuffer.SetData(waterVertices);
}
private void CreateBillboardVerticesFromList(List<Vector3> treeList) ...{
VertexPositionTexture[] billboardVertices = new VertexPositionTexture[treeList.Count * 6];
int i = 0;
foreach (Vector3 currentV3 in treeList)
...{
billboardVertices[i++] = new VertexPositionTexture(currentV3, new Vector2(0, 0));
billboardVertices[i++] = new VertexPositionTexture(currentV3, new Vector2(1, 0));
billboardVertices[i++] = new VertexPositionTexture(currentV3, new Vector2(1, 1));
billboardVertices[i++] = new VertexPositionTexture(currentV3, new Vector2(0, 0));
billboardVertices[i++] = new VertexPositionTexture(currentV3, new Vector2(1, 1));
billboardVertices[i++] = new VertexPositionTexture(currentV3, new Vector2(0, 1));
}
treeVertexBuffer = new VertexBuffer(device, billboardVertices.Length * VertexPositionTexture.SizeInBytes, BufferUsage.WriteOnly);
treeVertexBuffer.SetData(billboardVertices);
treeVertexDeclaration = new VertexDeclaration(device, VertexPositionTexture.VertexElements);
}
private List<Vector3> GenerateTreePositions(Texture2D treeMap, VertexMultitextured[] terrainVertices) ...{
Color[] treeMapColors = new Color[treeMap.Width * treeMap.Height];
treeMap.GetData(treeMapColors);
int[,] noiseData = new int[treeMap.Width, treeMap.Height];
for (int x = 0; x < treeMap.Width; x++)
for (int y = 0; y < treeMap.Height; y++)
noiseData[x, y] = treeMapColors[y + x * treeMap.Height].R;
List<Vector3> treeList = new List<Vector3> (); Random random = new Random();
for (int x = 0; x < terrainWidth; x++)
...{
for (int y = 0; y < terrainLength; y++)
...{
float terrainHeight = heightData[x, y];
if ((terrainHeight > 8) && (terrainHeight < 14))
...{
float flatness = Vector3.Dot(terrainVertices[x + y * terrainWidth].Normal, new Vector3(0, 1, 0));
float minFlatness = (float)Math.Cos(MathHelper.ToRadians(15));
if (flatness > minFlatness)
...{
float relx = (float)x / (float)terrainWidth;
float rely = (float)y / (float)terrainLength;
float noiseValueAtCurrentPosition = noiseData[(int)(relx * treeMap.Width), (int)(rely * treeMap.Height)];
float treeDensity;
if (noiseValueAtCurrentPosition > 200)
treeDensity = 5;
else if (noiseValueAtCurrentPosition > 150)
treeDensity = 4;
else if (noiseValueAtCurrentPosition > 100)
treeDensity = 3;
else
treeDensity = 0;
for (int currDetail = 0; currDetail < treeDensity; currDetail++)
...{
float rand1 = (float)random.Next(1000) / 1000.0f;
float rand2 = (float)random.Next(1000) / 1000.0f;
Vector3 treePos = new Vector3((float)x - rand1, 0, -(float)y - rand2);
treePos.Y = heightData[x, y];
treeList.Add(treePos);
}
}
}
}
}
return treeList;
}
private Texture2D CreateStaticMap(int resolution)
...{
Random rand = new Random();
Color[] noisyColors = new Color[resolution * resolution];
for (int x = 0; x < resolution; x++)
for (int y = 0; y < resolution; y++)
noisyColors[x + y * resolution] = new Color(new Vector3((float)rand.Next(1000) / 1000.0f, 0, 0));
Texture2D noiseImage = new Texture2D(device, resolution, resolution, 1, TextureUsage.None, SurfaceFormat.Color);
noiseImage.SetData(noisyColors);
return noiseImage;
}
private VertexPositionTexture[] SetUpFullscreenVertices()
...{
VertexPositionTexture[] vertices = new VertexPositionTexture[4];
vertices[0] = new VertexPositionTexture(new Vector3(-1, 1, 0f), new Vector2(0, 1));
vertices[1] = new VertexPositionTexture(new Vector3(1, 1, 0f), new Vector2(1, 1));
vertices[2] = new VertexPositionTexture(new Vector3(-1, -1, 0f), new Vector2(0, 0));
vertices[3] = new VertexPositionTexture(new Vector3(1, -1, 0f), new Vector2(1, 0));
return vertices;
}
protected override void UnloadContent()
...{
}
protected override void Update(GameTime gameTime)
...{
if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
this.Exit();
float timeDifference = (float)gameTime.ElapsedGameTime.TotalMilliseconds / 1000.0f;
ProcessInput(timeDifference);
base.Update(gameTime);
}
private void ProcessInput(float amount)
...{
MouseState currentMouseState = Mouse.GetState();
if (currentMouseState != originalMouseState)
...{
float xDifference = currentMouseState.X - originalMouseState.X;
float yDifference = currentMouseState.Y - originalMouseState.Y;
leftrightRot -= rotationSpeed * xDifference * amount;
updownRot -= rotationSpeed * yDifference * amount;
Mouse.SetPosition(device.Viewport.Width / 2, device.Viewport.Height / 2);
UpdateViewMatrix();
}
Vector3 moveVector = new Vector3(0, 0, 0);
KeyboardState keyState = Keyboard.GetState();
if (keyState.IsKeyDown(Keys.Up) || keyState.IsKeyDown(Keys.W))
moveVector += new Vector3(0, 0, -1);
if (keyState.IsKeyDown(Keys.Down) || keyState.IsKeyDown(Keys.S))
moveVector += new Vector3(0, 0, 1);
if (keyState.IsKeyDown(Keys.Right) || keyState.IsKeyDown(Keys.D))
moveVector += new Vector3(1, 0, 0);
if (keyState.IsKeyDown(Keys.Left) || keyState.IsKeyDown(Keys.A))
moveVector += new Vector3(-1, 0, 0);
if (keyState.IsKeyDown(Keys.Q))
moveVector += new Vector3(0, 1, 0);
if (keyState.IsKeyDown(Keys.Z))
moveVector += new Vector3(0, -1, 0);
AddToCameraPosition(moveVector * amount);
}
private void AddToCameraPosition(Vector3 vectorToAdd)
...{
Matrix cameraRotation = Matrix.CreateRotationX(updownRot) * Matrix.CreateRotationY(leftrightRot);
Vector3 rotatedVector = Vector3.Transform(vectorToAdd, cameraRotation);
cameraPosition += moveSpeed * rotatedVector;
UpdateViewMatrix();
}
private void UpdateViewMatrix()
...{
Matrix cameraRotation = Matrix.CreateRotationX(updownRot) * Matrix.CreateRotationY(leftrightRot);
Vector3 cameraOriginalTarget = new Vector3(0, 0, -1);
Vector3 cameraOriginalUpVector = new Vector3(0, 1, 0);
Vector3 cameraRotatedTarget = Vector3.Transform(cameraOriginalTarget, cameraRotation);
Vector3 cameraFinalTarget = cameraPosition + cameraRotatedTarget;
Vector3 cameraRotatedUpVector = Vector3.Transform(cameraOriginalUpVector, cameraRotation);
viewMatrix = Matrix.CreateLookAt(cameraPosition, cameraFinalTarget, cameraRotatedUpVector);
Vector3 reflCameraPosition = cameraPosition;
reflCameraPosition.Y = -cameraPosition.Y + waterHeight * 2;
Vector3 reflTargetPos = cameraFinalTarget;
reflTargetPos.Y = -cameraFinalTarget.Y + waterHeight * 2;
Vector3 cameraRight = Vector3.Transform(new Vector3(1, 0, 0), cameraRotation);
Vector3 invUpVector = Vector3.Cross(cameraRight, reflTargetPos - reflCameraPosition);
reflectionViewMatrix = Matrix.CreateLookAt(reflCameraPosition, reflTargetPos, invUpVector);
}
protected override void Draw(GameTime gameTime)
...{
float time = (float)gameTime.TotalGameTime.TotalMilliseconds / 100.0f;
DrawRefractionMap();
DrawReflectionMap();
GeneratePerlinNoise(time);
device.Clear(ClearOptions.Target | ClearOptions.DepthBuffer, Color.White, 1.0f, 0);
DrawSkyDome(viewMatrix);
DrawTerrain(viewMatrix);
DrawWater(time);
DrawBillboards(viewMatrix);
base.Draw(gameTime);
}
private void DrawTerrain(Matrix currentViewMatrix)
...{
effect.CurrentTechnique = effect.Techniques["MultiTextured"];
effect.Parameters["xTexture0"].SetValue(sandTexture);
effect.Parameters["xTexture1"].SetValue(grassTexture);
effect.Parameters["xTexture2"].SetValue(rockTexture);
effect.Parameters["xTexture3"].SetValue(snowTexture);
Matrix worldMatrix = Matrix.Identity;
effect.Parameters["xWorld"].SetValue(worldMatrix);
effect.Parameters["xView"].SetValue(currentViewMatrix);
effect.Parameters["xProjection"].SetValue(projectionMatrix);
effect.Parameters["xEnableLighting"].SetValue(true);
effect.Parameters["xAmbient"].SetValue(0.4f);
effect.Parameters["xLightDirection"].SetValue(new Vector3(-0.5f, -1, -0.5f));
effect.Begin();
foreach (EffectPass pass in effect.CurrentTechnique.Passes)
...{
pass.Begin();
device.Vertices[0].SetSource(terrainVertexBuffer, 0, VertexMultitextured.SizeInBytes);
device.Indices = terrainIndexBuffer;
device.VertexDeclaration = terrainVertexDeclaration;
int noVertices = terrainVertexBuffer.SizeInBytes / VertexMultitextured.SizeInBytes;
int noTriangles = terrainIndexBuffer.SizeInBytes / sizeof(int) / 3;
device.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, noVertices, 0, noTriangles);
pass.End();
}
effect.End();
}
private void DrawSkyDome(Matrix currentViewMatrix)
...{
device.RenderState.DepthBufferWriteEnable = false;
Matrix[] modelTransforms = new Matrix[skyDome.Bones.Count];
skyDome.CopyAbsoluteBoneTransformsTo(modelTransforms);
Matrix wMatrix = Matrix.CreateTranslation(0, -0.3f, 0) * Matrix.CreateScale(100) * Matrix.CreateTranslation(cameraPosition);
foreach (ModelMesh mesh in skyDome.Meshes)
...{
foreach (Effect currentEffect in mesh.Effects)
...{
Matrix worldMatrix = modelTransforms[mesh.ParentBone.Index] * wMatrix;
currentEffect.CurrentTechnique = currentEffect.Techniques["SkyDome"];
currentEffect.Parameters["xWorld"].SetValue(worldMatrix);
currentEffect.Parameters["xView"].SetValue(currentViewMatrix);
currentEffect.Parameters["xProjection"].SetValue(projectionMatrix);
currentEffect.Parameters["xTexture"].SetValue(cloudMap);
}
mesh.Draw();
}
device.RenderState.DepthBufferWriteEnable = true;
}
private Plane CreatePlane(float height, Vector3 planeNormalDirection, Matrix currentViewMatrix, bool clipSide)
...{
planeNormalDirection.Normalize();
Vector4 planeCoeffs = new Vector4(planeNormalDirection, height);
if (clipSide)
planeCoeffs *= -1;
Matrix worldViewProjection = currentViewMatrix * projectionMatrix;
Matrix inverseWorldViewProjection = Matrix.Invert(worldViewProjection);
inverseWorldViewProjection = Matrix.Transpose(inverseWorldViewProjection);
planeCoeffs = Vector4.Transform(planeCoeffs, inverseWorldViewProjection);
Plane finalPlane = new Plane(planeCoeffs);
return finalPlane;
}
private void DrawRefractionMap()
...{
Plane refractionPlane = CreatePlane(waterHeight + 1.5f, new Vector3(0, -1, 0), viewMatrix, false);
device.ClipPlanes[0].Plane = refractionPlane;
device.ClipPlanes[0].IsEnabled = true;
device.SetRenderTarget(0, refractionRenderTarget);
device.Clear(ClearOptions.Target | ClearOptions.DepthBuffer, Color.Black, 1.0f, 0);
DrawTerrain(viewMatrix);
device.ClipPlanes[0].IsEnabled = false;
device.SetRenderTarget(0, null);
refractionMap = refractionRenderTarget.GetTexture();
}
private void DrawReflectionMap()
...{
Plane reflectionPlane = CreatePlane(waterHeight - 0.5f, new Vector3(0, -1, 0), reflectionViewMatrix, true);
device.ClipPlanes[0].Plane = reflectionPlane;
device.ClipPlanes[0].IsEnabled = true;
device.SetRenderTarget(0, reflectionRenderTarget);
device.Clear(ClearOptions.Target | ClearOptions.DepthBuffer, Color.Black, 1.0f, 0);
DrawSkyDome(reflectionViewMatrix);
DrawTerrain(reflectionViewMatrix);
DrawBillboards(reflectionViewMatrix);
device.ClipPlanes[0].IsEnabled = false;
device.SetRenderTarget(0, null);
reflectionMap = reflectionRenderTarget.GetTexture();
}
private void DrawWater(float time)
...{
effect.CurrentTechnique = effect.Techniques["Water"];
Matrix worldMatrix = Matrix.Identity;
effect.Parameters["xWorld"].SetValue(worldMatrix);
effect.Parameters["xView"].SetValue(viewMatrix);
effect.Parameters["xReflectionView"].SetValue(reflectionViewMatrix);
effect.Parameters["xProjection"].SetValue(projectionMatrix);
effect.Parameters["xReflectionMap"].SetValue(reflectionMap);
effect.Parameters["xRefractionMap"].SetValue(refractionMap);
effect.Parameters["xWaterBumpMap"].SetValue(waterBumpMap);
effect.Parameters["xWaveLength"].SetValue(0.1f);
effect.Parameters["xWaveHeight"].SetValue(0.3f);
effect.Parameters["xCamPos"].SetValue(cameraPosition);
effect.Parameters["xTime"].SetValue(time);
effect.Parameters["xWindForce"].SetValue(0.002f);
effect.Parameters["xWindDirection"].SetValue(windDirection);
effect.Begin();
foreach (EffectPass pass in effect.CurrentTechnique.Passes)
...{
pass.Begin();
device.Vertices[0].SetSource(waterVertexBuffer, 0, VertexPositionTexture.SizeInBytes);
device.VertexDeclaration = waterVertexDeclaration;
int noVertices = waterVertexBuffer.SizeInBytes / VertexPositionTexture.SizeInBytes;
device.DrawPrimitives(PrimitiveType.TriangleList, 0, noVertices / 3);
pass.End();
}
effect.End();
}
private void DrawBillboards(Matrix currentViewMatrix)
...{
bbEffect.CurrentTechnique = bbEffect.Techniques["CylBillboard"];
bbEffect.Parameters["xWorld"].SetValue(Matrix.Identity);
bbEffect.Parameters["xView"].SetValue(currentViewMatrix);
bbEffect.Parameters["xProjection"].SetValue(projectionMatrix);
bbEffect.Parameters["xCamPos"].SetValue(cameraPosition);
bbEffect.Parameters["xAllowedRotDir"].SetValue(new Vector3(0, 1, 0));
bbEffect.Parameters["xBillboardTexture"].SetValue(treeTexture);
bbEffect.Begin();
device.Vertices[0].SetSource(treeVertexBuffer, 0, VertexPositionTexture.SizeInBytes);
device.VertexDeclaration = treeVertexDeclaration;
int noVertices = treeVertexBuffer.SizeInBytes / VertexPositionTexture.SizeInBytes;
int noTriangles = noVertices / 3;
...{
device.RenderState.AlphaTestEnable = true;
device.RenderState.AlphaFunction = CompareFunction.GreaterEqual;
device.RenderState.ReferenceAlpha = 200;
bbEffect.CurrentTechnique.Passes[0].Begin();
device.DrawPrimitives(PrimitiveType.TriangleList, 0, noTriangles);
bbEffect.CurrentTechnique.Passes[0].End();
}
...{
device.RenderState.DepthBufferWriteEnable = false;
device.RenderState.AlphaBlendEnable = true;
device.RenderState.SourceBlend = Blend.SourceAlpha;
device.RenderState.DestinationBlend = Blend.InverseSourceAlpha;
device.RenderState.AlphaTestEnable = true;
device.RenderState.AlphaFunction = CompareFunction.Less;
device.RenderState.ReferenceAlpha = 200;
bbEffect.CurrentTechnique.Passes[0].Begin();
device.DrawPrimitives(PrimitiveType.TriangleList, 0, noTriangles);
bbEffect.CurrentTechnique.Passes[0].End();
}
device.RenderState.AlphaBlendEnable = false;
device.RenderState.DepthBufferWriteEnable = true;
device.RenderState.AlphaTestEnable = false;
bbEffect.End();
}
private void GeneratePerlinNoise(float time)
...{
device.SetRenderTarget(0, cloudsRenderTarget);
device.Clear(ClearOptions.Target | ClearOptions.DepthBuffer, Color.Black, 1.0f, 0);
effect.CurrentTechnique = effect.Techniques["PerlinNoise"];
effect.Parameters["xTexture"].SetValue(cloudStaticMap);
effect.Parameters["xOvercast"].SetValue(1.1f);
effect.Parameters["xTime"].SetValue(time/1000.0f);
effect.Begin();
foreach (EffectPass pass in effect.CurrentTechnique.Passes)
...{
pass.Begin();
device.VertexDeclaration = fullScreenVertexDeclaration;
device.DrawUserPrimitives(PrimitiveType.TriangleStrip, fullScreenVertices, 0, 2);
pass.End();
}
effect.End();
device.SetRenderTarget(0, null);
cloudMap = cloudsRenderTarget.GetTexture();
}
}
}
完整的HLSL代码：
//----------------------------------------------------
//-- --
//-- www.riemers.net --
//-- Series 4: Advanced terrain --
//-- Shader code --
//-- --
//----------------------------------------------------
//------- Constants --------
float4x4 xView;
float4x4 xReflectionView;
float4x4 xProjection;
float4x4 xWorld;
float3 xLightDirection;
float xAmbient;
bool xEnableLighting;
float xWaveLength;
float xWaveHeight;
float3 xCamPos;
float xTime;
float xWindForce;
float3 xWindDirection;
float xOvercast;
//------- Texture Samplers --------
Texture xTexture;
sampler TextureSampler = sampler_state ...{ texture = <xTexture> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = mirror; AddressV = mirror;};Texture xTexture0;
sampler TextureSampler0 = sampler_state ...{ texture = <xTexture0> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = wrap; AddressV = wrap;};Texture xTexture1;
sampler TextureSampler1 = sampler_state ...{ texture = <xTexture1> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = wrap; AddressV = wrap;};Texture xTexture2;
sampler TextureSampler2 = sampler_state ...{ texture = <xTexture2> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = mirror; AddressV = mirror;};Texture xTexture3;
sampler TextureSampler3 = sampler_state ...{ texture = <xTexture3> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = mirror; AddressV = mirror;};Texture xReflectionMap;
sampler ReflectionSampler = sampler_state ...{ texture = <xReflectionMap> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = mirror; AddressV = mirror;};Texture xRefractionMap;
sampler RefractionSampler = sampler_state ...{ texture = <xRefractionMap> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = mirror; AddressV = mirror;};Texture xWaterBumpMap;
sampler WaterBumpMapSampler = sampler_state ...{ texture = <xWaterBumpMap> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = mirror; AddressV = mirror;};
//------- Technique: Textured --------
struct TVertexToPixel
...{
float4 Position : POSITION;
float4 Color : COLOR0;
float LightingFactor: TEXCOORD0;
float2 TextureCoords: TEXCOORD1;
};
struct TPixelToFrame
...{
float4 Color : COLOR0;
};
TVertexToPixel TexturedVS( float4 inPos : POSITION, float3 inNormal: NORMAL, float2 inTexCoords: TEXCOORD0)
...{
TVertexToPixel Output = (TVertexToPixel)0;
float4x4 preViewProjection = mul (xView, xProjection);
float4x4 preWorldViewProjection = mul (xWorld, preViewProjection);
Output.Position = mul(inPos, preWorldViewProjection);
Output.TextureCoords = inTexCoords;
float3 Normal = normalize(mul(normalize(inNormal), xWorld));
Output.LightingFactor = 1;
if (xEnableLighting)
Output.LightingFactor = saturate(dot(Normal, -xLightDirection));
return Output;
}
TPixelToFrame TexturedPS(TVertexToPixel PSIn)
...{
TPixelToFrame Output = (TPixelToFrame)0;
Output.Color = tex2D(TextureSampler, PSIn.TextureCoords);
Output.Color.rgb *= saturate(PSIn.LightingFactor + xAmbient);
return Output;
}
technique Textured_2_0
...{
pass Pass0
...{
VertexShader = compile vs_2_0 TexturedVS();
PixelShader = compile ps_2_0 TexturedPS();
}
}
technique Textured
...{
pass Pass0
...{
VertexShader = compile vs_1_1 TexturedVS();
PixelShader = compile ps_1_1 TexturedPS();
}
}
//------- Technique: Multitextured --------
struct MTVertexToPixel
...{
float4 Position : POSITION;
float4 Color : COLOR0;
float3 Normal : TEXCOORD0;
float2 TextureCoords : TEXCOORD1;
float4 LightDirection : TEXCOORD2;
float4 TextureWeights : TEXCOORD3;
float Depth : TEXCOORD4;
};
struct MTPixelToFrame
...{
float4 Color : COLOR0;
};
MTVertexToPixel MultiTexturedVS( float4 inPos : POSITION, float3 inNormal: NORMAL, float2 inTexCoords: TEXCOORD0, float4 inTexWeights: TEXCOORD1)
...{
MTVertexToPixel Output = (MTVertexToPixel)0;
float4x4 preViewProjection = mul (xView, xProjection);
float4x4 preWorldViewProjection = mul (xWorld, preViewProjection);
Output.Position = mul(inPos, preWorldViewProjection);
Output.Normal = mul(normalize(inNormal), xWorld);
Output.TextureCoords = inTexCoords;
Output.LightDirection.xyz = -xLightDirection;
Output.LightDirection.w = 1;
Output.TextureWeights = inTexWeights;
Output.Depth = Output.Position.z/Output.Position.w;
return Output;
}
MTPixelToFrame MultiTexturedPS(MTVertexToPixel PSIn)
...{
MTPixelToFrame Output = (MTPixelToFrame)0;
float lightingFactor = 1;
if (xEnableLighting)
lightingFactor = saturate(saturate(dot(PSIn.Normal, PSIn.LightDirection)) + xAmbient);
float blendDistance = 0.99f;
float blendWidth = 0.005f;
float blendFactor = clamp((PSIn.Depth-blendDistance)/blendWidth, 0, 1);
float4 farColor;
farColor = tex2D(TextureSampler0, PSIn.TextureCoords)*PSIn.TextureWeights.x;
farColor += tex2D(TextureSampler1, PSIn.TextureCoords)*PSIn.TextureWeights.y;
farColor += tex2D(TextureSampler2, PSIn.TextureCoords)*PSIn.TextureWeights.z;
farColor += tex2D(TextureSampler3, PSIn.TextureCoords)*PSIn.TextureWeights.w;
float4 nearColor;
float2 nearTextureCoords = PSIn.TextureCoords*3;
nearColor = tex2D(TextureSampler0, nearTextureCoords)*PSIn.TextureWeights.x;
nearColor += tex2D(TextureSampler1, nearTextureCoords)*PSIn.TextureWeights.y;
nearColor += tex2D(TextureSampler2, nearTextureCoords)*PSIn.TextureWeights.z;
nearColor += tex2D(TextureSampler3, nearTextureCoords)*PSIn.TextureWeights.w;
Output.Color = lerp(nearColor, farColor, blendFactor);
Output.Color *= lightingFactor;
return Output;
}
technique MultiTextured
...{
pass Pass0
...{
VertexShader = compile vs_1_1 MultiTexturedVS();
PixelShader = compile ps_2_0 MultiTexturedPS();
}
}
//------- Technique: Water --------
struct WVertexToPixel
...{
float4 Position : POSITION;
float4 ReflectionMapSamplingPos : TEXCOORD1;
float2 BumpMapSamplingPos : TEXCOORD2;
float4 RefractionMapSamplingPos : TEXCOORD3;
float4 Position3D : TEXCOORD4;
};
struct WPixelToFrame
...{
float4 Color : COLOR0;
};
WVertexToPixel WaterVS(float4 inPos : POSITION, float2 inTex: TEXCOORD)
...{
WVertexToPixel Output = (WVertexToPixel)0;
float4x4 preViewProjection = mul (xView, xProjection);
float4x4 preWorldViewProjection = mul (xWorld, preViewProjection);
float4x4 preReflectionViewProjection = mul (xReflectionView, xProjection);
float4x4 preWorldReflectionViewProjection = mul (xWorld, preReflectionViewProjection);
Output.Position = mul(inPos, preWorldViewProjection);
Output.ReflectionMapSamplingPos = mul(inPos, preWorldReflectionViewProjection);
Output.RefractionMapSamplingPos = mul(inPos, preWorldViewProjection);
Output.Position3D = mul(inPos, xWorld);
float3 windDir = normalize(xWindDirection);
float3 perpDir = cross(xWindDirection, float3(0,1,0));
float ydot = dot(inTex, xWindDirection.xz);
float xdot = dot(inTex, perpDir.xz);
float2 moveVector = float2(xdot, ydot);
moveVector.y += xTime*xWindForce;
Output.BumpMapSamplingPos = moveVector/xWaveLength;
return Output;
}
WPixelToFrame WaterPS(WVertexToPixel PSIn)
...{
WPixelToFrame Output = (WPixelToFrame)0;
float4 bumpColor = tex2D(WaterBumpMapSampler, PSIn.BumpMapSamplingPos);
float2 perturbation = xWaveHeight*(bumpColor.rg - 0.5f)*2.0f;
float2 ProjectedTexCoords;
ProjectedTexCoords.x = PSIn.ReflectionMapSamplingPos.x/PSIn.ReflectionMapSamplingPos.w/2.0f + 0.5f;
ProjectedTexCoords.y = -PSIn.ReflectionMapSamplingPos.y/PSIn.ReflectionMapSamplingPos.w/2.0f + 0.5f;
float2 perturbatedTexCoords = ProjectedTexCoords + perturbation;
float4 reflectiveColor = tex2D(ReflectionSampler, perturbatedTexCoords);
float2 ProjectedRefrTexCoords;
ProjectedRefrTexCoords.x = PSIn.RefractionMapSamplingPos.x/PSIn.RefractionMapSamplingPos.w/2.0f + 0.5f;
ProjectedRefrTexCoords.y = -PSIn.RefractionMapSamplingPos.y/PSIn.RefractionMapSamplingPos.w/2.0f + 0.5f;
float2 perturbatedRefrTexCoords = ProjectedRefrTexCoords + perturbation;
float4 refractiveColor = tex2D(RefractionSampler, perturbatedRefrTexCoords);
float3 eyeVector = normalize(xCamPos - PSIn.Position3D);
float3 normalVector = (bumpColor.rbg-0.5f)*2.0f;
float fresnelTerm = dot(eyeVector, normalVector);
float4 combinedColor = lerp(reflectiveColor, refractiveColor, fresnelTerm);
float4 dullColor = float4(0.3f, 0.3f, 0.5f, 1.0f);
Output.Color = lerp(combinedColor, dullColor, 0.2f);
float3 reflectionVector = -reflect(xLightDirection, normalVector);
float specular = dot(normalize(reflectionVector), normalize(eyeVector));
specular = pow(specular, 256);
Output.Color.rgb += specular;
return Output;
}
technique Water
...{
pass Pass0
...{
VertexShader = compile vs_1_1 WaterVS();
PixelShader = compile ps_2_0 WaterPS();
}
}
//------- Technique: PerlinNoise --------
struct PNVertexToPixel
...{
float4 Position : POSITION;
float2 TextureCoords : TEXCOORD0;
};
struct PNPixelToFrame
...{
float4 Color : COLOR0;
};
PNVertexToPixel PerlinVS(float4 inPos : POSITION, float2 inTexCoords: TEXCOORD)
...{
PNVertexToPixel Output = (PNVertexToPixel)0;
Output.Position = inPos;
Output.TextureCoords = inTexCoords;
return Output;
}
PNPixelToFrame PerlinPS(PNVertexToPixel PSIn)
...{
PNPixelToFrame Output = (PNPixelToFrame)0;
float2 move = float2(0,1);
float4 perlin = tex2D(TextureSampler, (PSIn.TextureCoords)+xTime*move)/2;
perlin += tex2D(TextureSampler, (PSIn.TextureCoords)*2+xTime*move)/4;
perlin += tex2D(TextureSampler, (PSIn.TextureCoords)*4+xTime*move)/8;
perlin += tex2D(TextureSampler, (PSIn.TextureCoords)*8+xTime*move)/16;
perlin += tex2D(TextureSampler, (PSIn.TextureCoords)*16+xTime*move)/32;
perlin += tex2D(TextureSampler, (PSIn.TextureCoords)*32+xTime*move)/32;
Output.Color.rgb = 1.0f-pow(perlin.r, xOvercast)*2.0f;
Output.Color.a =1;
return Output;
}
technique PerlinNoise
...{
pass Pass0
...{
VertexShader = compile vs_1_1 PerlinVS();
PixelShader = compile ps_2_0 PerlinPS();
}
}
//------- Technique: SkyDome --------
struct SDVertexToPixel
...{
float4 Position : POSITION;
float2 TextureCoords : TEXCOORD0;
float4 ObjectPosition : TEXCOORD1;
};
struct SDPixelToFrame
...{
float4 Color : COLOR0;
};
SDVertexToPixel SkyDomeVS( float4 inPos : POSITION, float2 inTexCoords: TEXCOORD0)
...{
SDVertexToPixel Output = (SDVertexToPixel)0;
float4x4 preViewProjection = mul (xView, xProjection);
float4x4 preWorldViewProjection = mul (xWorld, preViewProjection);
Output.Position = mul(inPos, preWorldViewProjection);
Output.TextureCoords = inTexCoords;
Output.ObjectPosition = inPos;
return Output;
}
SDPixelToFrame SkyDomePS(SDVertexToPixel PSIn)
...{
SDPixelToFrame Output = (SDPixelToFrame)0;
float4 topColor = float4(0.3f, 0.3f, 0.8f, 1);
float4 bottomColor = 1;
float4 baseColor = lerp(bottomColor, topColor, saturate((PSIn.ObjectPosition.y)/0.4f));
float4 cloudValue = tex2D(TextureSampler, PSIn.TextureCoords).r;
Output.Color = lerp(baseColor,1, cloudValue);
return Output;
}
technique SkyDome
...{
pass Pass0
...{
VertexShader = compile vs_1_1 SkyDomeVS();
PixelShader = compile ps_2_0 SkyDomePS();
}
}
发布时间：2009/12/29 上午10:28:45 阅读次数：6451
