3D系列4.11 波浪 初级凹凸映射
现在我们的水面看起来象镜子,我们需要添加一些波浪让它更真实。那应该如何做?我们使用一个非常简单的技巧而无需进行正弦和余弦的计算(波浪的数学算式)。对水面的每个像素,我们将稍微改变一些每个像素的采样位置,而不是从反射贴图的正确位置进行采样,我把这叫做纹理坐标扰动(texture coordinate perturbation)。
一种方法是将水面分割成许多小三角形,在XNA程序中每帧更新它们的纹理坐标。这对CPU来说计算量很大,几乎不可能完成。正确的方法是仍使用两个三角形,但在像素着色器中进行纹理坐标的计算。
但仍有一个问题:我们需要调整每个像素的纹理坐标多大距离?要解决这个问题,试着想象一下自然中的现象:如果无风,水面是平静的,看起来像镜子。如果有风,,水面会产生波浪,但在波浪的顶部和底部,水面是平的,因此反射仍然很完美:在每个波浪的顶部和底部扰动最小。但是,波浪的侧面肯定不是水平的,因此需要最大的扰动!
我们需要的是每个像素的平整度,为此我们将使用一张真实水面的图像。但是,我们感兴趣的并不是要图像本身,而是每个像素的平整度。这就是高度图:如果你有一张256x256的水面图像A,它的高度图B也是一张256x256的图像,每个像素的颜色表示与图像A中对应像素的颜色区别。
高度贴图是一个数学术语;在游戏中通常叫做凹凸贴图,下图是水面的凹凸贴图:
这个图像的每个像素包含三个值,一个值对应一个颜色。这三个值对应法线向量的三个分量。例如,如果一个像素对应的面是平的,法线向量指向上方。它的X和Z分量为0,Y分量为1。在颜色中,红色和绿色为0,蓝色为1,所以,整个贴图会是蓝色的。
但是,因为水面不是平的,每个像素的法线并不相同,红色和绿色通道包含法线偏离X和Z轴的大小信息。因此红色和绿色分量越大,法线离开向上方向就越远,水面就越不平。
蓝色分量只用来创建法线向量,法线需要三个分量,但本例中我们只关心水面上像素的平整度,这是使用红色和绿色分量表示的。在XNA代码中,我们无需进行太多操作:只需将凹凸贴图传递到着色器中。所以声明以下变量: Texture2D waterBumpMap; 在LoadTextures方法中加载这个纹理:
waterBumpMap = Content.Load<Texture2D> ("waterbump");
在DrawWater 方法中将它传递到着色器:
effect.Parameters["xWaterBumpMap"].SetValue(waterBumpMap);
这就是XNA代码。让我们进入HLSL部分。首先声明凹凸贴图:
Texture xWaterBumpMap; sampler WaterBumpMapSampler = sampler_state { texture = <xWaterBumpMap>; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = mirror; AddressV = mirror; };
声明两个变量:
float xWaveLength; float xWaveHeight;
我认为它们的名称不需要进一步解释。现在开始更新着色器代码。截止上一章,我们已经定义了6个顶点的纹理坐标构成水面,现在需要这些坐标采样凹凸贴图,所以需要调整顶点输出结构和着色器让它可以传递到像素着色器:
struct WVertexToPixel { float4 Position : POSITION; float4 ReflectionMapSamplingPos : TEXCOORD1; float2 BumpMapSamplingPos : TEXCOORD2; }; ... Output.BumpMapSamplingPos = inTex/xWaveLength;
最后一行代码除以xWaveLength:这个值大会使纹理坐标小,这样凹凸贴图会扩展到一个很大的区域内。
现在看一下像素着色器。首先采样凹凸贴图:
float4 bumpColor = tex2D(WaterBumpMapSampler, PSIn.BumpMapSamplingPos);
这次,bumpColor的红色和绿色值表示采样反射贴图的坐标需要被扰动多少。所以你想让它包含范围为-1到+1之间的值。但是,颜色值范围在0和1之间!所以,在保存颜色前需要通过将值从[-1,1]区间映射到[0,1]才能创建高度图。这可以通过除2加0.5实现。例如,如果法线没有调整,X和Z分量为0,Y分量为1,当转换为颜色是为(0.5, 0.5, 1),这就是从凹凸贴图中获取的颜色。当然,我们需要将凹凸贴图中的值从[0,1]范围重新映射到[-1,1]范围:
float2 perturbation = xWaveHeight*(bumpColor.rg - 0.5f)*2.0f;
最终获取了扰动过的纹理坐标:
float2 perturbatedTexCoords = ProjectedTexCoords + perturbation;
使用这个最终的纹理坐标采样反射贴图:
Output.Color = tex2D(ReflectionSampler, perturbatedTexCoords);
这就是HLSL代码,我们要做的就是在DrawWater方法中设置2个变量:
effect.Parameters["xWaveLength"].SetValue(0.1f); effect.Parameters["xWaveHeight"].SetValue(0.3f);
运行代码后截图如下: 现在看起来像水面了。
- 试着改变xWaveLength和xWaveHeight
- 如果反射剪裁平面过高或过低会发生什么?
下面是目前为止的XNA代码,红色部分为相对上一章改变的代码:
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;
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namespace XNAseries4
{
public struct VertexMultitextured
{
public Vector3 Position;
public Vector3 Normal;
public Vector4 TextureCoordinate;
public Vector4 TexWeights;
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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 ),
};
}
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public class Game1 : Microsoft.Xna.Framework.Game
{
GraphicsDeviceManager graphics;
GraphicsDevice device;
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int terrainWidth;
int terrainLength;
float[,] heightData;
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VertexBuffer terrainVertexBuffer;
IndexBuffer terrainIndexBuffer;
VertexDeclaration terrainVertexDeclaration;
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VertexBuffer waterVertexBuffer;
VertexDeclaration waterVertexDeclaration;
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Effect effect;
Matrix viewMatrix;
Matrix projectionMatrix;
Matrix reflectionViewMatrix;
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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;
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Texture2D grassTexture;
Texture2D sandTexture;
Texture2D rockTexture;
Texture2D snowTexture;
Texture2D cloudMap;
Texture2D waterBumpMap;
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Model skyDome;
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const float waterHeight = 5.0f;
RenderTarget2D refractionRenderTarget;
Texture2D refractionMap;
RenderTarget2D reflectionRenderTarget;
Texture2D reflectionMap;
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public Game1()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
}
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protected override void Initialize()
{
graphics.PreferredBackBufferWidth = 500;
graphics.PreferredBackBufferHeight = 500;
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graphics.ApplyChanges();
Window.Title = "Riemer's XNA Tutorials -- Series 4";
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base.Initialize();
}
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protected override void LoadContent()
{
device = GraphicsDevice;
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effect = Content.Load<Effect> ("Series4Effects");
UpdateViewMatrix();
projectionMatrix = Matrix.CreatePerspectiveFieldOfView(MathHelper.PiOver4, device.Viewport.AspectRatio, 0.3f, 1000.0f);
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Mouse.SetPosition(device.Viewport.Width / 2, device.Viewport.Height / 2);
originalMouseState = Mouse.GetState();
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skyDome = Content.Load<Model> ("dome"); skyDome.Meshes[0].MeshParts[0].Effect = effect.Clone(device);
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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);
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LoadVertices();
LoadTextures();
}
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private void LoadVertices()
{
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Texture2D heightMap = Content.Load<Texture2D> ("heightmap"); LoadHeightData(heightMap);
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VertexMultitextured[] terrainVertices = SetUpTerrainVertices();
int[] terrainIndices = SetUpTerrainIndices();
terrainVertices = CalculateNormals(terrainVertices, terrainIndices);
CopyToTerrainBuffers(terrainVertices, terrainIndices);
terrainVertexDeclaration = new VertexDeclaration(device, VertexMultitextured.VertexElements);
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SetUpWaterVertices();
waterVertexDeclaration = new VertexDeclaration(device, VertexPositionTexture.VertexElements);
}
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private void LoadTextures()
{
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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");
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waterBumpMap = Content.Load<Texture2D> ("waterbump");
}
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private void LoadHeightData(Texture2D heightMap)
{
float minimumHeight = float.MaxValue;
float maximumHeight = float.MinValue;
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terrainWidth = heightMap.Width;
terrainLength = heightMap.Height;
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Color[] heightMapColors = new Color[terrainWidth * terrainLength];
heightMap.GetData(heightMapColors);
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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];
}
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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;
}
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private VertexMultitextured[] SetUpTerrainVertices()
{
VertexMultitextured[] terrainVertices = new VertexMultitextured[terrainWidth * terrainLength];
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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;
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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);
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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;
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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;
}
}
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return terrainVertices;
}
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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;
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indices[counter++] = topLeft;
indices[counter++] = lowerRight;
indices[counter++] = lowerLeft;
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indices[counter++] = topLeft;
indices[counter++] = topRight;
indices[counter++] = lowerRight;
}
}
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return indices;
}
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private VertexMultitextured[] CalculateNormals(VertexMultitextured[] vertices, int[] indices)
{
for (int i = 0; i < vertices.Length; i++)
vertices[i].Normal = new Vector3(0, 0, 0);
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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];
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Vector3 side1 = vertices[index1].Position - vertices[index3].Position;
Vector3 side2 = vertices[index1].Position - vertices[index2].Position;
Vector3 normal = Vector3.Cross(side1, side2);
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vertices[index1].Normal += normal;
vertices[index2].Normal += normal;
vertices[index3].Normal += normal;
}
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for (int i = 0; i < vertices.Length; i++)
vertices[i].Normal.Normalize();
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return vertices;
}
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private void CopyToTerrainBuffers(VertexMultitextured[] vertices, int[] indices)
{
terrainVertexBuffer = new VertexBuffer(device, vertices.Length * VertexMultitextured.SizeInBytes, BufferUsage.WriteOnly);
terrainVertexBuffer.SetData(vertices);
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terrainIndexBuffer = new IndexBuffer(device, typeof(int), indices.Length, BufferUsage.WriteOnly);
terrainIndexBuffer.SetData(indices);
}
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private void SetUpWaterVertices()
{
VertexPositionTexture[] waterVertices = new VertexPositionTexture[6];
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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));
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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));
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waterVertexBuffer = new VertexBuffer(device, waterVertices.Length * VertexPositionTexture.SizeInBytes, BufferUsage.WriteOnly);
waterVertexBuffer.SetData(waterVertices);
}
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protected override void UnloadContent()
{
}
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protected override void Update(GameTime gameTime)
{
if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
this.Exit();
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float timeDifference = (float)gameTime.ElapsedGameTime.TotalMilliseconds / 1000.0f;
ProcessInput(timeDifference);
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base.Update(gameTime);
}
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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();
}
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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);
}
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private void AddToCameraPosition(Vector3 vectorToAdd)
{
Matrix cameraRotation = Matrix.CreateRotationX(updownRot) * Matrix.CreateRotationY(leftrightRot);
Vector3 rotatedVector = Vector3.Transform(vectorToAdd, cameraRotation);
cameraPosition += moveSpeed * rotatedVector;
UpdateViewMatrix();
}
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private void UpdateViewMatrix()
{
Matrix cameraRotation = Matrix.CreateRotationX(updownRot) * Matrix.CreateRotationY(leftrightRot);
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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);
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viewMatrix = Matrix.CreateLookAt(cameraPosition, cameraFinalTarget, cameraRotatedUpVector);
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Vector3 reflCameraPosition = cameraPosition;
reflCameraPosition.Y = -cameraPosition.Y + waterHeight * 2;
Vector3 reflTargetPos = cameraFinalTarget;
reflTargetPos.Y = -cameraFinalTarget.Y + waterHeight * 2;
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Vector3 cameraRight = Vector3.Transform(new Vector3(1, 0, 0), cameraRotation);
Vector3 invUpVector = Vector3.Cross(cameraRight, reflTargetPos - reflCameraPosition);
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reflectionViewMatrix = Matrix.CreateLookAt(reflCameraPosition, reflTargetPos, invUpVector);
}
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protected override void Draw(GameTime gameTime)
{
float time = (float)gameTime.TotalGameTime.TotalMilliseconds / 100.0f;
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DrawRefractionMap();
DrawReflectionMap();
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device.Clear(ClearOptions.Target | ClearOptions.DepthBuffer, Color.Black, 1.0f, 0);
DrawSkyDome(viewMatrix);
DrawTerrain(viewMatrix);
DrawWater(time);
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base.Draw(gameTime);
}
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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);
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Matrix worldMatrix = Matrix.Identity;
effect.Parameters["xWorld"].SetValue(worldMatrix);
effect.Parameters["xView"].SetValue(currentViewMatrix);
effect.Parameters["xProjection"].SetValue(projectionMatrix);
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effect.Parameters["xEnableLighting"].SetValue(true);
effect.Parameters["xAmbient"].SetValue(0.4f);
effect.Parameters["xLightDirection"].SetValue(new Vector3(-0.5f, -1, -0.5f));
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effect.Begin();
foreach (EffectPass pass in effect.CurrentTechnique.Passes)
{
pass.Begin();
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device.Vertices[0].SetSource(terrainVertexBuffer, 0, VertexMultitextured.SizeInBytes);
device.Indices = terrainIndexBuffer;
device.VertexDeclaration = terrainVertexDeclaration;
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int noVertices = terrainVertexBuffer.SizeInBytes / VertexMultitextured.SizeInBytes;
int noTriangles = terrainIndexBuffer.SizeInBytes / sizeof(int) / 3;
device.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, noVertices, 0, noTriangles);
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pass.End();
}
effect.End();
}
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private void DrawSkyDome(Matrix currentViewMatrix)
{
device.RenderState.DepthBufferWriteEnable = false;
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Matrix[] modelTransforms = new Matrix[skyDome.Bones.Count];
skyDome.CopyAbsoluteBoneTransformsTo(modelTransforms);
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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["Textured"];
currentEffect.Parameters["xWorld"].SetValue(worldMatrix);
currentEffect.Parameters["xView"].SetValue(currentViewMatrix);
currentEffect.Parameters["xProjection"].SetValue(projectionMatrix);
currentEffect.Parameters["xTexture"].SetValue(cloudMap);
currentEffect.Parameters["xEnableLighting"].SetValue(false);
}
mesh.Draw();
}
device.RenderState.DepthBufferWriteEnable = true;
}
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private Plane CreatePlane(float height, Vector3 planeNormalDirection, Matrix currentViewMatrix, bool clipSide)
{
planeNormalDirection.Normalize();
Vector4 planeCoeffs = new Vector4(planeNormalDirection, height);
if (clipSide)
planeCoeffs *= -1;
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Matrix worldViewProjection = currentViewMatrix * projectionMatrix;
Matrix inverseWorldViewProjection = Matrix.Invert(worldViewProjection);
inverseWorldViewProjection = Matrix.Transpose(inverseWorldViewProjection);
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planeCoeffs = Vector4.Transform(planeCoeffs, inverseWorldViewProjection);
Plane finalPlane = new Plane(planeCoeffs);
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return finalPlane;
}
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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;
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device.SetRenderTarget(0, null);
refractionMap = refractionRenderTarget.GetTexture();
}
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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);
DrawTerrain(reflectionViewMatrix);
DrawSkyDome(reflectionViewMatrix);
device.ClipPlanes[0].IsEnabled = false;
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device.SetRenderTarget(0, null);
reflectionMap = reflectionRenderTarget.GetTexture();
}
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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);
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effect.Begin();
foreach (EffectPass pass in effect.CurrentTechnique.Passes)
{
pass.Begin();
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device.Vertices[0].SetSource(waterVertexBuffer, 0, VertexPositionTexture.SizeInBytes);
device.VertexDeclaration = waterVertexDeclaration;
int noVertices = waterVertexBuffer.SizeInBytes / VertexPositionTexture.SizeInBytes;
device.DrawPrimitives(PrimitiveType.TriangleList, 0, noVertices / 3);
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pass.End();
}
effect.End();
}
}
}
HLSL文件,红色部分为相对上一章改变的代码:
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//-- --
//-- www.riemers.net --
//-- Series 4: Advanced terrain --
//-- Shader code --
//-- --
//----------------------------------------------------
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//------- Constants --------
float4x4 xView;
float4x4 xReflectionView;
float4x4 xProjection;
float4x4 xWorld;
float3 xLightDirection;
float xAmbient;
bool xEnableLighting;
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float xWaveLength;
float xWaveHeight;
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//------- Texture Samplers --------
Texture xTexture;
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sampler TextureSampler = sampler_state { texture = <xTexture> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = mirror; AddressV = mirror;};Texture xTexture0;
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sampler TextureSampler0 = sampler_state { texture = <xTexture0> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = wrap; AddressV = wrap;};Texture xTexture1;
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sampler TextureSampler1 = sampler_state { texture = <xTexture1> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = wrap; AddressV = wrap;};Texture xTexture2;
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sampler TextureSampler2 = sampler_state { texture = <xTexture2> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = mirror; AddressV = mirror;};Texture xTexture3;
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sampler TextureSampler3 = sampler_state { texture = <xTexture3> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = mirror; AddressV = mirror;};Texture xReflectionMap;
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sampler ReflectionSampler = sampler_state { texture = <xReflectionMap> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = mirror; AddressV = mirror;};Texture xRefractionMap;
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sampler RefractionSampler = sampler_state { texture = <xRefractionMap> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = mirror; AddressV = mirror;};
Texture xWaterBumpMap;
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sampler WaterBumpMapSampler = sampler_state { texture = <xWaterBumpMap> ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = mirror; AddressV = mirror;};
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//------- Technique: Textured --------
struct TVertexToPixel
{
float4 Position : POSITION;
float4 Color : COLOR0;
float LightingFactor: TEXCOORD0;
float2 TextureCoords: TEXCOORD1;
};
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struct TPixelToFrame
{
float4 Color : COLOR0;
};
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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);
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Output.Position = mul(inPos, preWorldViewProjection);
Output.TextureCoords = inTexCoords;
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float3 Normal = normalize(mul(normalize(inNormal), xWorld));
Output.LightingFactor = 1;
if (xEnableLighting)
Output.LightingFactor = saturate(dot(Normal, -xLightDirection));
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return Output;
}
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TPixelToFrame TexturedPS(TVertexToPixel PSIn)
{
TPixelToFrame Output = (TPixelToFrame)0;
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Output.Color = tex2D(TextureSampler, PSIn.TextureCoords);
Output.Color.rgb *= saturate(PSIn.LightingFactor + xAmbient);
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return Output;
}
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technique Textured_2_0
{
pass Pass0
{
VertexShader = compile vs_2_0 TexturedVS();
PixelShader = compile ps_2_0 TexturedPS();
}
}
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technique Textured
{
pass Pass0
{
VertexShader = compile vs_1_1 TexturedVS();
PixelShader = compile ps_1_1 TexturedPS();
}
}
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//------- 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;
};
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struct MTPixelToFrame
{
float4 Color : COLOR0;
};
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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);
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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;
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return Output;
}
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MTPixelToFrame MultiTexturedPS(MTVertexToPixel PSIn)
{
MTPixelToFrame Output = (MTPixelToFrame)0;
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float lightingFactor = 1;
if (xEnableLighting)
lightingFactor = saturate(saturate(dot(PSIn.Normal, PSIn.LightDirection)) + xAmbient);
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float blendDistance = 0.99f;
float blendWidth = 0.005f;
float blendFactor = clamp((PSIn.Depth-blendDistance)/blendWidth, 0, 1);
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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;
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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;
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Output.Color = lerp(nearColor, farColor, blendFactor);
Output.Color *= lightingFactor;
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return Output;
}
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technique MultiTextured
{
pass Pass0
{
VertexShader = compile vs_1_1 MultiTexturedVS();
PixelShader = compile ps_2_0 MultiTexturedPS();
}
}
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//------- Technique: Water --------
struct WVertexToPixel
{
float4 Position : POSITION;
float4 ReflectionMapSamplingPos : TEXCOORD1;
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float2 BumpMapSamplingPos : TEXCOORD2;
};
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struct WPixelToFrame
{
float4 Color : COLOR0;
};
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WVertexToPixel WaterVS(float4 inPos : POSITION, float2 inTex: TEXCOORD)
{
WVertexToPixel Output = (WVertexToPixel)0;
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float4x4 preViewProjection = mul (xView, xProjection);
float4x4 preWorldViewProjection = mul (xWorld, preViewProjection);
float4x4 preReflectionViewProjection = mul (xReflectionView, xProjection);
float4x4 preWorldReflectionViewProjection = mul (xWorld, preReflectionViewProjection);
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Output.Position = mul(inPos, preWorldViewProjection);
Output.ReflectionMapSamplingPos = mul(inPos, preWorldReflectionViewProjection);
Output.BumpMapSamplingPos = inTex/xWaveLength;
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return Output;
}
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WPixelToFrame WaterPS(WVertexToPixel PSIn)
{
WPixelToFrame Output = (WPixelToFrame)0;
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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;
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float4 bumpColor = tex2D(WaterBumpMapSampler, PSIn.BumpMapSamplingPos);
float2 perturbation = xWaveHeight*(bumpColor.rg - 0.5f)*2.0f;
float2 perturbatedTexCoords = ProjectedTexCoords + perturbation;
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Output.Color = tex2D(ReflectionSampler, perturbatedTexCoords);
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return Output;
}
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technique Water
{
pass Pass0
{
VertexShader = compile vs_1_1 WaterVS();
PixelShader = compile ps_2_0 WaterPS();
}
}
发布时间:2009/12/17 下午3:27:24 阅读次数:7767