在 Unity 中使用 Shells 技术实现 Fur
Implementing Fur with Shells technique in Unity
我正在尝试使用 Shells technique 在 Unity 中实现毛发。 Fins 技术被故意排除在外，因为我希望它在低端手机（主要是 Android 设备）上 运行 并且需要 OpenGL ES 3.0 及更高版本，而 Shell技术只需要OpenGL ES 2.0.
有一个基于 XNA 的 Shell 技术示例，我尝试将其移植到 Unity 中，但没有成功。 Here 是 XNA 项目的文章。
XNA 着色器：
float4x4 World;
float4x4 View;
float4x4 Projection;
float CurrentLayer; //value between 0 and 1
float MaxHairLength; //maximum hair length
texture FurTexture;
sampler FurSampler = sampler_state
{
Texture = (FurTexture);
MinFilter = Point;
MagFilter = Point;
MipFilter = Point;
AddressU = Wrap;
AddressV = Wrap;
};
struct VertexShaderInput
{
float3 Position : POSITION0;
float3 Normal : NORMAL0;
float2 TexCoord : TEXCOORD0;
};
struct VertexShaderOutput
{
float4 Position : POSITION0;
float2 TexCoord : TEXCOORD0;
};
VertexShaderOutput FurVertexShader(VertexShaderInput input)
{
VertexShaderOutput output;
float3 pos;
pos = input.Position + input.Normal * MaxHairLength * CurrentLayer;
float4 worldPosition = mul(float4(pos,1), World);
float4 viewPosition = mul(worldPosition, View);
output.Position = mul(viewPosition, Projection);
output.TexCoord = input.TexCoord;
return output;
}
float4 FurPixelShader(VertexShaderOutput input) : COLOR0
{
return tex2D(FurSampler, input.TexCoord);
}
technique Fur
{
pass Pass1
{
AlphaBlendEnable = true;
SrcBlend = SRCALPHA;
DestBlend = INVSRCALPHA;
CullMode = None;
VertexShader = compile vs_2_0 FurVertexShader();
PixelShader = compile ps_2_0 FurPixelShader();
}
}
控制着色器的XNAC#脚本：
/// <summary>
/// This is the main type for your game
/// </summary>
public class Game1 : Microsoft.Xna.Framework.Game
{
GraphicsDeviceManager graphics;
SpriteBatch spriteBatch;
public Game1()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
}
//simple camera for use in the game
Camera camera;
//texture containing fur data
Texture2D furTexture;
//effect for fur shaders
Effect furEffect;
//number of layers of fur
int nrOfLayers = 60;
//total length of the hair
float maxHairLength = 2.0f;
//density of hair
float density = 0.2f;
Texture2D furColorTexture;
//movement vectors
Vector3 gravity = new Vector3(0, -1.0f, 0);
Vector3 forceDirection = Vector3.Zero;
//final displacement for hair
Vector3 displacement;
/// <summary>
/// Allows the game to perform any initialization it needs to before starting to run.
/// This is where it can query for any required services and load any non-graphic
/// related content. Calling base.Initialize will enumerate through any components
/// and initialize them as well.
/// </summary>
protected override void Initialize()
{
// TODO: Add your initialization logic here
camera = new Camera(this);
Components.Add(camera);
base.Initialize();
}
/// <summary>
/// LoadContent will be called once per game and is the place to load
/// all of your content.
/// </summary>
protected override void LoadContent()
{
// Create a new SpriteBatch, which can be used to draw textures.
spriteBatch = new SpriteBatch(GraphicsDevice);
//generate the geometry
GenerateGeometry();
//load the effect
furEffect = Content.Load<Effect>("FurEffect");
//create the texture
furTexture = new Texture2D(GraphicsDevice,
256, 256, 1,
TextureUsage.None,
SurfaceFormat.Color);
//fill the texture
FillFurTexture(furTexture, density);
furColorTexture = Content.Load<Texture2D>("bigtiger");
}
/// <summary>
/// UnloadContent will be called once per game and is the place to unload
/// all content.
/// </summary>
protected override void UnloadContent()
{
// TODO: Unload any non ContentManager content here
}
/// <summary>
/// Allows the game to run logic such as updating the world,
/// checking for collisions, gathering input, and playing audio.
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values.</param>
protected override void Update(GameTime gameTime)
{
// Allows the game to exit
if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
this.Exit();
// TODO: Add your update logic here
base.Update(gameTime);
}
/// <summary>
/// This is called when the game should draw itself.
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values.</param>
protected override void Draw(GameTime gameTime)
{
forceDirection.X = (float)Math.Sin(gameTime.TotalGameTime.TotalSeconds) * 0.5f;
displacement = gravity + forceDirection;
furEffect.Parameters["Displacement"].SetValue(displacement);
graphics.GraphicsDevice.Clear(Color.CornflowerBlue);
furEffect.Parameters["World"].SetValue(Matrix.CreateTranslation(0, -10, 0));
furEffect.Parameters["View"].SetValue(camera.View);
furEffect.Parameters["Projection"].SetValue(camera.Projection);
furEffect.Parameters["MaxHairLength"].SetValue(maxHairLength);
furEffect.Parameters["FurTexture"].SetValue(furTexture);
furEffect.Parameters["Texture"].SetValue(furColorTexture);
furEffect.Begin();
for (int i = 0; i < nrOfLayers; i++)
{
furEffect.Parameters["CurrentLayer"].SetValue((float)i / nrOfLayers);
furEffect.CommitChanges();
furEffect.CurrentTechnique.Passes[0].Begin();
DrawGeometry();
furEffect.CurrentTechnique.Passes[0].End();
}
furEffect.End();
base.Draw(gameTime);
}
/// <summary>
/// This functions prepares a texture to be used for fur rendering
/// </summary>
/// <param name="furTexture">This will contain the final texture</param>
/// <param name="density">Hair density in [0..1] range </param>
private void FillFurTexture(Texture2D furTexture, float density)
{
//read the width and height of the texture
int width = furTexture.Width;
int height = furTexture.Height;
int totalPixels = width * height;
//an array to hold our pixels
Color[] colors;
colors = new Color[totalPixels];
//random number generator
Random rand = new Random();
//initialize all pixels to transparent black
for (int i = 0; i < totalPixels; i++)
colors[i] = Color.TransparentBlack;
//compute the number of opaque pixels = nr of hair strands
int nrStrands = (int)(density * totalPixels);
//compute the number of strands that stop at each layer
int strandsPerLayer = nrStrands / nrOfLayers;
//fill texture with opaque pixels
for (int i = 0; i < nrStrands; i++)
{
int x, y;
//random position on the texture
x = rand.Next(height);
y = rand.Next(width);
//compute max layer
int max_layer = i / strandsPerLayer;
//normalize into [0..1] range
float max_layer_n = (float)max_layer / (float)nrOfLayers;
//put color (which has an alpha value of 255, i.e. opaque)
//max_layer_n needs to be multiplied by 255 to achieve a color in [0..255] range
colors[x * width + y] = new Color((byte)(max_layer_n * 255), 0, 0, 255);
}
//set the pixels on the texture.
furTexture.SetData<Color>(colors);
}
VertexPositionNormalTexture[] vertices;
private void GenerateGeometry()
{
vertices = new VertexPositionNormalTexture[6];
vertices[0] = new VertexPositionNormalTexture(
new Vector3(-10, 0, 0),
-Vector3.UnitZ,
new Vector2(0, 0));
vertices[1] = new VertexPositionNormalTexture(
new Vector3(10, 20, 0),
-Vector3.UnitZ,
new Vector2(1, 1));
vertices[2] = new VertexPositionNormalTexture(
new Vector3(-10, 20, 0),
-Vector3.UnitZ,
new Vector2(0, 1));
vertices[3] = vertices[0];
vertices[4] = new VertexPositionNormalTexture(
new Vector3(10, 0, 0),
-Vector3.UnitZ,
new Vector2(1, 0));
vertices[5] = vertices[1];
}
private void DrawGeometry()
{
using (VertexDeclaration vdecl = new VertexDeclaration(
GraphicsDevice,
VertexPositionNormalTexture.VertexElements))
{
GraphicsDevice.VertexDeclaration = vdecl;
GraphicsDevice.DrawUserPrimitives<VertexPositionNormalTexture>(PrimitiveType.TriangleList, vertices, 0, 2);
}
}
}
我小心地将着色器和控制脚本逐行移植到Unity。
移植的 Unity 着色器：
Shader "Programmer/Fur Shader"
{
Properties
{
_MainTex("Texture", 2D) = "white" {}
//_TintColor("Tint Color", Color) = (1,1,1,1)
}
SubShader
{
Tags{ "Queue" = "Transparent" "RenderType" = "Transparent" }
LOD 100
Blend SrcAlpha One
Blend DstAlpha OneMinusSrcAlpha
ZWrite Off
Cull Off
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
// make fog work
//#pragma multi_compile_fog
#include "UnityCG.cginc"
//In
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
//Out
struct v2f
{
float2 uv : TEXCOORD0;
UNITY_FOG_COORDS(1)
float4 vertex : SV_POSITION;
};
struct VertexShaderInput
{
float3 Position : POSITION0;
float3 Normal : NORMAL0;
float2 TexCoord : TEXCOORD0;
};
struct VertexShaderOutput
{
float4 Position : POSITION0;
float2 TexCoord : TEXCOORD0;
};
sampler2D _MainTex;
float4 _MainTex_ST;
//Test variable/delete after
float4 _TintColor;
//The variables
float4x4 World;
float4x4 View;
float4x4 Projection;
float CurrentLayer; //value between 0 and 1
float MaxHairLength; //maximum hair length
VertexShaderOutput vert(VertexShaderInput input)
{
VertexShaderOutput output;
float3 pos;
pos = input.Position + input.Normal * MaxHairLength * CurrentLayer;
float4 worldPosition = mul(float4(pos, 1), World);
float4 viewPosition = mul(worldPosition, View);
output.Position = mul(viewPosition, Projection);
output.TexCoord = input.TexCoord;
return output;
}
float4 frag(VertexShaderOutput i) : COLOR0
{
return tex2D(_MainTex, i.TexCoord);
}
ENDCG
}
}
}
移植的Unity控制着色器的C#脚本：
public class Game1 : MonoBehaviour
{
public Material material;
public Vector3 pos = new Vector3(0f, 0.98f, -9.54f);
//simple camera for use in the game
private new Camera camera;
//texture containing fur data
public Texture2D furTexture;
//effect for fur shaders
//Effect furEffect;
//number of layers of fur
public int nrOfLayers = 40;
//total length of the hair
public float maxHairLength = 2.0f;
//density of hair
public float density = 0.2f;
//[Space(20)]
//public Vector3 dirWorldVal = new Vector3(0, -10, 0);
void Start()
{
Initialize();
GenerateGeometry();
}
public void Update()
{
Draw();
}
void Initialize()
{
//Initialize the camera
camera = Camera.main;
//create the texture
furTexture = new Texture2D(256, 256, TextureFormat.ARGB32, false);
furTexture.wrapModeU = TextureWrapMode.Repeat;
furTexture.wrapModeV = TextureWrapMode.Repeat;
furTexture.filterMode = FilterMode.Point;
//fill the texture
FillFurTexture(furTexture, density);
/*XNA's SurfaceFormat.Color is ARGB.
//https://gamedev.stackexchange.com/a/6442/98839*/
if (material.mainTexture != null)
{
material.mainTexture.wrapModeU = TextureWrapMode.Repeat;
material.mainTexture.wrapModeV = TextureWrapMode.Repeat;
material.mainTexture.filterMode = FilterMode.Point;
}
}
bool firstDraw = true;
protected void Draw()
{
camera.backgroundColor = CornflowerBlue();
Matrix4x4 worldValue = Matrix4x4.Translate(pos);
Matrix4x4 viewValue = camera.projectionMatrix;
// viewValue = camera.worldToCameraMatrix;
Matrix4x4 projectionValue = camera.projectionMatrix;
material.SetMatrix("World", worldValue);
material.SetMatrix("View", viewValue);
material.SetMatrix("Projection", projectionValue); //Causes object to disappear
material.SetFloat("MaxHairLength", maxHairLength);
if (firstDraw)
material.SetTexture("_MainTex", furTexture);
//furEffect.Begin();
for (int i = 0; i < nrOfLayers; i++)
{
material.SetFloat("CurrentLayer", (float)i / nrOfLayers);
DrawGeometry();
}
if (firstDraw)
{
material.mainTexture.wrapModeU = TextureWrapMode.Repeat;
material.mainTexture.wrapModeV = TextureWrapMode.Repeat;
material.mainTexture.filterMode = FilterMode.Point;
}
if (firstDraw)
firstDraw = false;
}
void DrawGeometry()
{
Quaternion rotation = Quaternion.Euler(0, 180, 0);
Graphics.DrawMesh(verticesMesh, pos, rotation, material, 0, camera);
}
private VertexPositionNormalTexture[] verticesPText;
public Mesh verticesMesh;
private void GenerateGeometry()
{
verticesPText = new VertexPositionNormalTexture[6];
verticesPText[0] = new VertexPositionNormalTexture(new Vector3(-10, 0, 0),
-UnitZ(),
new Vector2(0, 0));
verticesPText[1] = new VertexPositionNormalTexture(new Vector3(10, 20, 0),
-UnitZ(),
new Vector2(1, 1));
verticesPText[2] = new VertexPositionNormalTexture(new Vector3(-10, 20, 0),
-UnitZ(),
new Vector2(0, 1));
verticesPText[3] = verticesPText[0];
verticesPText[4] = new VertexPositionNormalTexture(new Vector3(10, 0, 0),
-UnitZ(),
new Vector2(1, 0));
verticesPText[5] = verticesPText[1];
verticesMesh = VertexPositionNormalTextureToUnityMesh(verticesPText);
}
Mesh VertexPositionNormalTextureToUnityMesh(VertexPositionNormalTexture[] vpnt)
{
Vector3[] vertices = new Vector3[vpnt.Length];
Vector3[] normals = new Vector3[vpnt.Length];
Vector2[] uvs = new Vector2[vpnt.Length];
int[] triangles = new int[vpnt.Length];
//Copy variables to create a mesh
for (int i = 0; i < vpnt.Length; i++)
{
vertices[i] = vpnt[i].Position;
normals[i] = vpnt[i].Normal;
uvs[i] = vpnt[i].TextureCoordinate;
triangles[i] = i;
}
Mesh mesh = new Mesh();
mesh.vertices = vertices;
mesh.normals = normals;
mesh.uv = uvs;
mesh.triangles = triangles;
return mesh;
}
private void FillFurTexture(Texture2D furTexture, float density)
{
//read the width and height of the texture
int width = furTexture.width;
int height = furTexture.height;
int totalPixels = width * height;
//an array to hold our pixels
Color32[] colors = new Color32[totalPixels];
//random number generator
System.Random rand = new System.Random();
//initialize all pixels to transparent black
for (int i = 0; i < totalPixels; i++)
colors[i] = TransparentBlack();
//compute the number of opaque pixels = nr of hair strands
int nrStrands = (int)(density * totalPixels);
//fill texture with opaque pixels
for (int i = 0; i < nrStrands; i++)
{
int x, y;
//random position on the texture
x = rand.Next(height);
y = rand.Next(width);
//put color (which has an alpha value of 255, i.e. opaque)
colors[x * width + y] = Gold();
}
//set the pixels on the texture.
furTexture.SetPixels32(colors);
// actually apply all SetPixels, don't recalculate mip levels
furTexture.Apply();
}
Color32 TransparentBlack()
{
//http://www.monogame.net/documentation/?page=P_Microsoft_Xna_Framework_Color_TransparentBlack
Color32 color = new Color32(0, 0, 0, 0);
return color;
}
Color32 Gold()
{
//http://www.monogame.net/documentation/?page=P_Microsoft_Xna_Framework_Color_Gold
Color32 color = new Color32(255, 215, 0, 255);
return color;
}
Color32 CornflowerBlue()
{
//http://www.monogame.net/documentation/?page=P_Microsoft_Xna_Framework_Color_CornflowerBlue
Color32 color = new Color32(100, 149, 237, 255);
return color;
}
public static Vector3 UnitZ()
{
return new Vector3(0f, 0f, 1f);
}
}
为 Unity
移植的 VertexPositionNormalTexture 结构
public struct VertexPositionNormalTexture
{
public Vector3 Position;
public Vector3 Normal;
public Vector2 TextureCoordinate;
//public static readonly VertexDeclaration VertexDeclaration;
public VertexPositionNormalTexture(Vector3 position, Vector3 normal, Vector2 textureCoordinate)
{
this.Position = position;
this.Normal = normal;
this.TextureCoordinate = textureCoordinate;
}
public override int GetHashCode()
{
// TODO: FIc gethashcode
return 0;
}
public override string ToString()
{
return string.Format("{{Position:{0} Normal:{1} TextureCoordinate:{2}}}", new object[] { this.Position, this.Normal, this.TextureCoordinate });
}
public static bool operator ==(VertexPositionNormalTexture left, VertexPositionNormalTexture right)
{
return (((left.Position == right.Position) && (left.Normal == right.Normal)) && (left.TextureCoordinate == right.TextureCoordinate));
}
public static bool operator !=(VertexPositionNormalTexture left, VertexPositionNormalTexture right)
{
return !(left == right);
}
public override bool Equals(object obj)
{
if (obj == null)
{
return false;
}
if (obj.GetType() != base.GetType())
{
return false;
}
return (this == ((VertexPositionNormalTexture)obj));
}
}
移植的Unity工作不正常。没有贝壳，输出图像是平的。
这是 预期的 结果XNA（工作正常）：
但这是我在 Unity 中看到的（无壳）：
最终图像应该如下图所示，但我无法继续进行移植工作，因为基本实现无法在 Unity 中正常工作。
我的脚本public变量设置：
为什么移植后的Unity结果是平的？我错过了什么吗？
编辑：
提到了可能的backface问题，因为Unity使用的是左手坐标系，而XNA使用的是右手坐标系。
我翻转了 UnitZ() 值并尝试反转网格顶点，但屏幕上没有任何内容。 这不太可能是问题所在。
Unity 正在对 material 进行批量优化。您可以在帧调试器中看到这一点。每个 DrawGeometry 调用都使用相同的 CurrentLayer 值。每次调用 DrawMesh 都需要使用属性块。
设置新的 material 会导致一些闪烁。
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
namespace foo {
public class FurBehavior : MonoBehaviour
{
public Material material;
public Vector3 pos = new Vector3(0f, 0.98f, -9.54f);
//simple camera for use in the game
private new Camera camera;
//texture containing fur data
public Texture2D furTexture;
//effect for fur shaders
//Effect furEffect;
//number of layers of fur
public int nrOfLayers = 40;
//total length of the hair
public float maxHairLength = 2.0f;
//density of hair
public float density = 0.2f;
//[Space(20)]
//public Vector3 dirWorldVal = new Vector3(0, -10, 0);
void Start()
{
this.transform.position = new Vector3(0f, 0.98f, -9.54f);
this.transform.rotation = Quaternion.Euler(0, 180, 0);
Initialize();
GenerateGeometry();
}
public void Update()
{
Draw();
}
void Initialize()
{
//Initialize the camera
camera = Camera.main;
//create the texture
furTexture = new Texture2D(256, 256, TextureFormat.ARGB32, false);
furTexture.wrapModeU = TextureWrapMode.Repeat;
furTexture.wrapModeV = TextureWrapMode.Repeat;
//furTexture.filterMode = FilterMode.Point;
//fill the texture
FillFurTexture(furTexture, density);
/*XNA's SurfaceFormat.Color is ARGB.
//https://gamedev.stackexchange.com/a/6442/98839*/
if (material.mainTexture != null)
{
material.mainTexture.wrapModeU = TextureWrapMode.Repeat;
material.mainTexture.wrapModeV = TextureWrapMode.Repeat;
// material.mainTexture.filterMode = FilterMode.Point;
}
}
bool firstDraw = true;
protected void Draw()
{
var pos = this.transform.position;
camera.backgroundColor = CornflowerBlue();
Matrix4x4 worldValue = Matrix4x4.Translate(pos);
Matrix4x4 viewValue = camera.projectionMatrix;
// viewValue = camera.worldToCameraMatrix;
Matrix4x4 projectionValue = camera.projectionMatrix;
material.SetMatrix("World", worldValue);
material.SetMatrix("View", viewValue);
material.SetMatrix("Projection", projectionValue); //Causes object to disappear
material.SetFloat("MaxHairLength", maxHairLength);
//if (firstDraw)
material.SetTexture("_MainTex", furTexture);
//furEffect.Begin();
for (int i = 0; i < nrOfLayers; i++)
{
var propertyBlock = new MaterialPropertyBlock();
var layer = (float)i / (float)nrOfLayers;
propertyBlock.SetFloat("CurrentLayer", layer);
propertyBlock.SetFloat("MaxHairLength", maxHairLength);
propertyBlock.SetColor("_TintColor", new Color(layer, layer, layer, layer));
DrawGeometry(propertyBlock);
}
if (firstDraw)
{
material.mainTexture.wrapModeU = TextureWrapMode.Repeat;
material.mainTexture.wrapModeV = TextureWrapMode.Repeat;
material.mainTexture.filterMode = FilterMode.Point;
}
if (firstDraw)
firstDraw = false;
}
void DrawGeometry(MaterialPropertyBlock props)
{
var rot = Quaternion.Euler(0, 180, 0);
Graphics.DrawMesh(verticesMesh, pos, rot, material, 0, camera, 0, props);
}
private VertexPositionNormalTexture[] verticesPText;
public Mesh verticesMesh;
private void GenerateGeometry()
{
var UnitZ = new Vector3(0, 0, 1);
var verticesPText = new VertexPositionNormalTexture[6];
verticesPText[5] = new VertexPositionNormalTexture(new Vector3(-10, 0, 0),
-UnitZ,
new Vector2(0, 0));
verticesPText[4] = new VertexPositionNormalTexture(new Vector3(10, 20, 0),
-UnitZ,
new Vector2(1, 1));
verticesPText[3] = new VertexPositionNormalTexture(new Vector3(-10, 20, 0),
-UnitZ,
new Vector2(0, 1));
verticesPText[2] = verticesPText[5];
verticesPText[1] = new VertexPositionNormalTexture(new Vector3(10, 0, 0),
-UnitZ,
new Vector2(1, 0));
verticesPText[0] = verticesPText[4];
}
Mesh VertexPositionNormalTextureToUnityMesh(VertexPositionNormalTexture[] vpnt)
{
Vector3[] vertices = new Vector3[vpnt.Length];
Vector3[] normals = new Vector3[vpnt.Length];
Vector2[] uvs = new Vector2[vpnt.Length];
int[] triangles = new int[vpnt.Length];
//Copy variables to create a mesh
for (int i = 0; i < vpnt.Length; i++)
{
vertices[i] = vpnt[i].Position;
normals[i] = vpnt[i].Normal;
uvs[i] = vpnt[i].TextureCoordinate;
triangles[i] = i;
}
Mesh mesh = new Mesh();
mesh.vertices = vertices;
mesh.normals = normals;
mesh.uv = uvs;
mesh.MarkDynamic();
mesh.triangles = triangles;
mesh.UploadMeshData(false);
return mesh;
}
private void FillFurTexture(Texture2D furTexture, float density)
{
//read the width and height of the texture
int width = furTexture.width;
int height = furTexture.height;
int totalPixels = width * height;
//an array to hold our pixels
Color32[] colors = new Color32[totalPixels];
//random number generator
System.Random rand = new System.Random();
//initialize all pixels to transparent black
for (int i = 0; i < totalPixels; i++)
colors[i] = TransparentBlack();
//compute the number of opaque pixels = nr of hair strands
int nrStrands = (int)(density * totalPixels);
//fill texture with opaque pixels
for (int i = 0; i < nrStrands; i++)
{
int x, y;
//random position on the texture
x = rand.Next(height);
y = rand.Next(width);
//put color (which has an alpha value of 255, i.e. opaque)
// colors[x * width + y] = new Color32((byte)255, (byte)x, (byte)y, (byte)255);
colors[x * width + y] = Gold();
}
//set the pixels on the texture.
furTexture.SetPixels32(colors);
// actually apply all SetPixels, don't recalculate mip levels
furTexture.Apply();
}
Color32 TransparentBlack()
{
//http://www.monogame.net/documentation/?page=P_Microsoft_Xna_Framework_Color_TransparentBlack
Color32 color = new Color32(0, 0, 0, 0);
return color;
}
Color32 Gold()
{
//http://www.monogame.net/documentation/?page=P_Microsoft_Xna_Framework_Color_Gold
Color32 color = new Color32(255, 215, 0, 255);
return color;
}
Color32 CornflowerBlue()
{
//http://www.monogame.net/documentation/?page=P_Microsoft_Xna_Framework_Color_CornflowerBlue
Color32 color = new Color32(100, 149, 237, 255);
return color;
}
public static Vector3 UnitZ()
{
return new Vector3(0f, 0f, 1f);
}
}
}
我还修改了着色器以可视化外壳。
// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with
'UnityObjectToClipPos(*)'
Shader "Programmer/Fur Shader"
{
Properties
{
_MainTex("Texture", 2D) = "white" {}
_TintColor("Tint Color", Color) = (1,1,1,1)
}
SubShader
{
Tags{ "Queue" = "Transparent" "RenderType" = "Transparent" }
LOD 100
//Blend SrcAlpha One
//Blend DstAlpha OneMinusSrcAlpha
Blend SrcAlpha OneMinusSrcAlpha
ZWrite Off
Cull Off
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
// make fog work
//#pragma multi_compile_fog
#include "UnityCG.cginc"
//In
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
//Out
struct v2f
{
float2 uv : TEXCOORD0;
UNITY_FOG_COORDS(1)
float4 vertex : SV_POSITION;
};
struct VertexShaderInput
{
float3 Position : POSITION0;
float3 Normal : NORMAL0;
float2 TexCoord : TEXCOORD0;
};
struct VertexShaderOutput
{
float4 Position : POSITION0;
float2 TexCoord : TEXCOORD0;
float4 Tint: COLOR1;
};
sampler2D _MainTex;
float4 _MainTex_ST;
//Test variable/delete after
float4 _TintColor;
//The variables
float4x4 World;
float4x4 View;
float4x4 Projection;
float CurrentLayer; //value between 0 and 1
float MaxHairLength; //maximum hair length
VertexShaderOutput vert(VertexShaderInput input)
{
VertexShaderOutput output;
float3 pos;
pos = input.Position + input.Normal * MaxHairLength * CurrentLayer;
//float4 worldPosition = mul(float4(pos, 1), World);
//float4 viewPosition = mul(worldPosition, View);
output.Position = UnityObjectToClipPos(pos);
output.TexCoord = input.TexCoord;
output.Tint = float4(CurrentLayer, CurrentLayer, 0, 1);
return output;
}
float4 frag(VertexShaderOutput i) : COLOR0
{
float4 t = tex2D(_MainTex, i.TexCoord) * i.Tint;
return t;//float4(t, i.x, i.y, 1);
}
ENDCG
}
}
}
这是在修改参数并稍微移动相机后的样子。
我正在尝试使用 Shells technique 在 Unity 中实现毛发。 Fins 技术被故意排除在外，因为我希望它在低端手机（主要是 Android 设备）上 运行 并且需要 OpenGL ES 3.0 及更高版本，而 Shell技术只需要OpenGL ES 2.0.
有一个基于 XNA 的 Shell 技术示例，我尝试将其移植到 Unity 中，但没有成功。 Here 是 XNA 项目的文章。
XNA 着色器：
float4x4 World;
float4x4 View;
float4x4 Projection;
float CurrentLayer; //value between 0 and 1
float MaxHairLength; //maximum hair length
texture FurTexture;
sampler FurSampler = sampler_state
{
Texture = (FurTexture);
MinFilter = Point;
MagFilter = Point;
MipFilter = Point;
AddressU = Wrap;
AddressV = Wrap;
};
struct VertexShaderInput
{
float3 Position : POSITION0;
float3 Normal : NORMAL0;
float2 TexCoord : TEXCOORD0;
};
struct VertexShaderOutput
{
float4 Position : POSITION0;
float2 TexCoord : TEXCOORD0;
};
VertexShaderOutput FurVertexShader(VertexShaderInput input)
{
VertexShaderOutput output;
float3 pos;
pos = input.Position + input.Normal * MaxHairLength * CurrentLayer;
float4 worldPosition = mul(float4(pos,1), World);
float4 viewPosition = mul(worldPosition, View);
output.Position = mul(viewPosition, Projection);
output.TexCoord = input.TexCoord;
return output;
}
float4 FurPixelShader(VertexShaderOutput input) : COLOR0
{
return tex2D(FurSampler, input.TexCoord);
}
technique Fur
{
pass Pass1
{
AlphaBlendEnable = true;
SrcBlend = SRCALPHA;
DestBlend = INVSRCALPHA;
CullMode = None;
VertexShader = compile vs_2_0 FurVertexShader();
PixelShader = compile ps_2_0 FurPixelShader();
}
}
控制着色器的XNAC#脚本：
/// <summary>
/// This is the main type for your game
/// </summary>
public class Game1 : Microsoft.Xna.Framework.Game
{
GraphicsDeviceManager graphics;
SpriteBatch spriteBatch;
public Game1()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
}
//simple camera for use in the game
Camera camera;
//texture containing fur data
Texture2D furTexture;
//effect for fur shaders
Effect furEffect;
//number of layers of fur
int nrOfLayers = 60;
//total length of the hair
float maxHairLength = 2.0f;
//density of hair
float density = 0.2f;
Texture2D furColorTexture;
//movement vectors
Vector3 gravity = new Vector3(0, -1.0f, 0);
Vector3 forceDirection = Vector3.Zero;
//final displacement for hair
Vector3 displacement;
/// <summary>
/// Allows the game to perform any initialization it needs to before starting to run.
/// This is where it can query for any required services and load any non-graphic
/// related content. Calling base.Initialize will enumerate through any components
/// and initialize them as well.
/// </summary>
protected override void Initialize()
{
// TODO: Add your initialization logic here
camera = new Camera(this);
Components.Add(camera);
base.Initialize();
}
/// <summary>
/// LoadContent will be called once per game and is the place to load
/// all of your content.
/// </summary>
protected override void LoadContent()
{
// Create a new SpriteBatch, which can be used to draw textures.
spriteBatch = new SpriteBatch(GraphicsDevice);
//generate the geometry
GenerateGeometry();
//load the effect
furEffect = Content.Load<Effect>("FurEffect");
//create the texture
furTexture = new Texture2D(GraphicsDevice,
256, 256, 1,
TextureUsage.None,
SurfaceFormat.Color);
//fill the texture
FillFurTexture(furTexture, density);
furColorTexture = Content.Load<Texture2D>("bigtiger");
}
/// <summary>
/// UnloadContent will be called once per game and is the place to unload
/// all content.
/// </summary>
protected override void UnloadContent()
{
// TODO: Unload any non ContentManager content here
}
/// <summary>
/// Allows the game to run logic such as updating the world,
/// checking for collisions, gathering input, and playing audio.
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values.</param>
protected override void Update(GameTime gameTime)
{
// Allows the game to exit
if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
this.Exit();
// TODO: Add your update logic here
base.Update(gameTime);
}
/// <summary>
/// This is called when the game should draw itself.
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values.</param>
protected override void Draw(GameTime gameTime)
{
forceDirection.X = (float)Math.Sin(gameTime.TotalGameTime.TotalSeconds) * 0.5f;
displacement = gravity + forceDirection;
furEffect.Parameters["Displacement"].SetValue(displacement);
graphics.GraphicsDevice.Clear(Color.CornflowerBlue);
furEffect.Parameters["World"].SetValue(Matrix.CreateTranslation(0, -10, 0));
furEffect.Parameters["View"].SetValue(camera.View);
furEffect.Parameters["Projection"].SetValue(camera.Projection);
furEffect.Parameters["MaxHairLength"].SetValue(maxHairLength);
furEffect.Parameters["FurTexture"].SetValue(furTexture);
furEffect.Parameters["Texture"].SetValue(furColorTexture);
furEffect.Begin();
for (int i = 0; i < nrOfLayers; i++)
{
furEffect.Parameters["CurrentLayer"].SetValue((float)i / nrOfLayers);
furEffect.CommitChanges();
furEffect.CurrentTechnique.Passes[0].Begin();
DrawGeometry();
furEffect.CurrentTechnique.Passes[0].End();
}
furEffect.End();
base.Draw(gameTime);
}
/// <summary>
/// This functions prepares a texture to be used for fur rendering
/// </summary>
/// <param name="furTexture">This will contain the final texture</param>
/// <param name="density">Hair density in [0..1] range </param>
private void FillFurTexture(Texture2D furTexture, float density)
{
//read the width and height of the texture
int width = furTexture.Width;
int height = furTexture.Height;
int totalPixels = width * height;
//an array to hold our pixels
Color[] colors;
colors = new Color[totalPixels];
//random number generator
Random rand = new Random();
//initialize all pixels to transparent black
for (int i = 0; i < totalPixels; i++)
colors[i] = Color.TransparentBlack;
//compute the number of opaque pixels = nr of hair strands
int nrStrands = (int)(density * totalPixels);
//compute the number of strands that stop at each layer
int strandsPerLayer = nrStrands / nrOfLayers;
//fill texture with opaque pixels
for (int i = 0; i < nrStrands; i++)
{
int x, y;
//random position on the texture
x = rand.Next(height);
y = rand.Next(width);
//compute max layer
int max_layer = i / strandsPerLayer;
//normalize into [0..1] range
float max_layer_n = (float)max_layer / (float)nrOfLayers;
//put color (which has an alpha value of 255, i.e. opaque)
//max_layer_n needs to be multiplied by 255 to achieve a color in [0..255] range
colors[x * width + y] = new Color((byte)(max_layer_n * 255), 0, 0, 255);
}
//set the pixels on the texture.
furTexture.SetData<Color>(colors);
}
VertexPositionNormalTexture[] vertices;
private void GenerateGeometry()
{
vertices = new VertexPositionNormalTexture[6];
vertices[0] = new VertexPositionNormalTexture(
new Vector3(-10, 0, 0),
-Vector3.UnitZ,
new Vector2(0, 0));
vertices[1] = new VertexPositionNormalTexture(
new Vector3(10, 20, 0),
-Vector3.UnitZ,
new Vector2(1, 1));
vertices[2] = new VertexPositionNormalTexture(
new Vector3(-10, 20, 0),
-Vector3.UnitZ,
new Vector2(0, 1));
vertices[3] = vertices[0];
vertices[4] = new VertexPositionNormalTexture(
new Vector3(10, 0, 0),
-Vector3.UnitZ,
new Vector2(1, 0));
vertices[5] = vertices[1];
}
private void DrawGeometry()
{
using (VertexDeclaration vdecl = new VertexDeclaration(
GraphicsDevice,
VertexPositionNormalTexture.VertexElements))
{
GraphicsDevice.VertexDeclaration = vdecl;
GraphicsDevice.DrawUserPrimitives<VertexPositionNormalTexture>(PrimitiveType.TriangleList, vertices, 0, 2);
}
}
}
我小心地将着色器和控制脚本逐行移植到Unity。
移植的 Unity 着色器：
Shader "Programmer/Fur Shader"
{
Properties
{
_MainTex("Texture", 2D) = "white" {}
//_TintColor("Tint Color", Color) = (1,1,1,1)
}
SubShader
{
Tags{ "Queue" = "Transparent" "RenderType" = "Transparent" }
LOD 100
Blend SrcAlpha One
Blend DstAlpha OneMinusSrcAlpha
ZWrite Off
Cull Off
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
// make fog work
//#pragma multi_compile_fog
#include "UnityCG.cginc"
//In
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
//Out
struct v2f
{
float2 uv : TEXCOORD0;
UNITY_FOG_COORDS(1)
float4 vertex : SV_POSITION;
};
struct VertexShaderInput
{
float3 Position : POSITION0;
float3 Normal : NORMAL0;
float2 TexCoord : TEXCOORD0;
};
struct VertexShaderOutput
{
float4 Position : POSITION0;
float2 TexCoord : TEXCOORD0;
};
sampler2D _MainTex;
float4 _MainTex_ST;
//Test variable/delete after
float4 _TintColor;
//The variables
float4x4 World;
float4x4 View;
float4x4 Projection;
float CurrentLayer; //value between 0 and 1
float MaxHairLength; //maximum hair length
VertexShaderOutput vert(VertexShaderInput input)
{
VertexShaderOutput output;
float3 pos;
pos = input.Position + input.Normal * MaxHairLength * CurrentLayer;
float4 worldPosition = mul(float4(pos, 1), World);
float4 viewPosition = mul(worldPosition, View);
output.Position = mul(viewPosition, Projection);
output.TexCoord = input.TexCoord;
return output;
}
float4 frag(VertexShaderOutput i) : COLOR0
{
return tex2D(_MainTex, i.TexCoord);
}
ENDCG
}
}
}
移植的Unity控制着色器的C#脚本：
public class Game1 : MonoBehaviour
{
public Material material;
public Vector3 pos = new Vector3(0f, 0.98f, -9.54f);
//simple camera for use in the game
private new Camera camera;
//texture containing fur data
public Texture2D furTexture;
//effect for fur shaders
//Effect furEffect;
//number of layers of fur
public int nrOfLayers = 40;
//total length of the hair
public float maxHairLength = 2.0f;
//density of hair
public float density = 0.2f;
//[Space(20)]
//public Vector3 dirWorldVal = new Vector3(0, -10, 0);
void Start()
{
Initialize();
GenerateGeometry();
}
public void Update()
{
Draw();
}
void Initialize()
{
//Initialize the camera
camera = Camera.main;
//create the texture
furTexture = new Texture2D(256, 256, TextureFormat.ARGB32, false);
furTexture.wrapModeU = TextureWrapMode.Repeat;
furTexture.wrapModeV = TextureWrapMode.Repeat;
furTexture.filterMode = FilterMode.Point;
//fill the texture
FillFurTexture(furTexture, density);
/*XNA's SurfaceFormat.Color is ARGB.
//https://gamedev.stackexchange.com/a/6442/98839*/
if (material.mainTexture != null)
{
material.mainTexture.wrapModeU = TextureWrapMode.Repeat;
material.mainTexture.wrapModeV = TextureWrapMode.Repeat;
material.mainTexture.filterMode = FilterMode.Point;
}
}
bool firstDraw = true;
protected void Draw()
{
camera.backgroundColor = CornflowerBlue();
Matrix4x4 worldValue = Matrix4x4.Translate(pos);
Matrix4x4 viewValue = camera.projectionMatrix;
// viewValue = camera.worldToCameraMatrix;
Matrix4x4 projectionValue = camera.projectionMatrix;
material.SetMatrix("World", worldValue);
material.SetMatrix("View", viewValue);
material.SetMatrix("Projection", projectionValue); //Causes object to disappear
material.SetFloat("MaxHairLength", maxHairLength);
if (firstDraw)
material.SetTexture("_MainTex", furTexture);
//furEffect.Begin();
for (int i = 0; i < nrOfLayers; i++)
{
material.SetFloat("CurrentLayer", (float)i / nrOfLayers);
DrawGeometry();
}
if (firstDraw)
{
material.mainTexture.wrapModeU = TextureWrapMode.Repeat;
material.mainTexture.wrapModeV = TextureWrapMode.Repeat;
material.mainTexture.filterMode = FilterMode.Point;
}
if (firstDraw)
firstDraw = false;
}
void DrawGeometry()
{
Quaternion rotation = Quaternion.Euler(0, 180, 0);
Graphics.DrawMesh(verticesMesh, pos, rotation, material, 0, camera);
}
private VertexPositionNormalTexture[] verticesPText;
public Mesh verticesMesh;
private void GenerateGeometry()
{
verticesPText = new VertexPositionNormalTexture[6];
verticesPText[0] = new VertexPositionNormalTexture(new Vector3(-10, 0, 0),
-UnitZ(),
new Vector2(0, 0));
verticesPText[1] = new VertexPositionNormalTexture(new Vector3(10, 20, 0),
-UnitZ(),
new Vector2(1, 1));
verticesPText[2] = new VertexPositionNormalTexture(new Vector3(-10, 20, 0),
-UnitZ(),
new Vector2(0, 1));
verticesPText[3] = verticesPText[0];
verticesPText[4] = new VertexPositionNormalTexture(new Vector3(10, 0, 0),
-UnitZ(),
new Vector2(1, 0));
verticesPText[5] = verticesPText[1];
verticesMesh = VertexPositionNormalTextureToUnityMesh(verticesPText);
}
Mesh VertexPositionNormalTextureToUnityMesh(VertexPositionNormalTexture[] vpnt)
{
Vector3[] vertices = new Vector3[vpnt.Length];
Vector3[] normals = new Vector3[vpnt.Length];
Vector2[] uvs = new Vector2[vpnt.Length];
int[] triangles = new int[vpnt.Length];
//Copy variables to create a mesh
for (int i = 0; i < vpnt.Length; i++)
{
vertices[i] = vpnt[i].Position;
normals[i] = vpnt[i].Normal;
uvs[i] = vpnt[i].TextureCoordinate;
triangles[i] = i;
}
Mesh mesh = new Mesh();
mesh.vertices = vertices;
mesh.normals = normals;
mesh.uv = uvs;
mesh.triangles = triangles;
return mesh;
}
private void FillFurTexture(Texture2D furTexture, float density)
{
//read the width and height of the texture
int width = furTexture.width;
int height = furTexture.height;
int totalPixels = width * height;
//an array to hold our pixels
Color32[] colors = new Color32[totalPixels];
//random number generator
System.Random rand = new System.Random();
//initialize all pixels to transparent black
for (int i = 0; i < totalPixels; i++)
colors[i] = TransparentBlack();
//compute the number of opaque pixels = nr of hair strands
int nrStrands = (int)(density * totalPixels);
//fill texture with opaque pixels
for (int i = 0; i < nrStrands; i++)
{
int x, y;
//random position on the texture
x = rand.Next(height);
y = rand.Next(width);
//put color (which has an alpha value of 255, i.e. opaque)
colors[x * width + y] = Gold();
}
//set the pixels on the texture.
furTexture.SetPixels32(colors);
// actually apply all SetPixels, don't recalculate mip levels
furTexture.Apply();
}
Color32 TransparentBlack()
{
//http://www.monogame.net/documentation/?page=P_Microsoft_Xna_Framework_Color_TransparentBlack
Color32 color = new Color32(0, 0, 0, 0);
return color;
}
Color32 Gold()
{
//http://www.monogame.net/documentation/?page=P_Microsoft_Xna_Framework_Color_Gold
Color32 color = new Color32(255, 215, 0, 255);
return color;
}
Color32 CornflowerBlue()
{
//http://www.monogame.net/documentation/?page=P_Microsoft_Xna_Framework_Color_CornflowerBlue
Color32 color = new Color32(100, 149, 237, 255);
return color;
}
public static Vector3 UnitZ()
{
return new Vector3(0f, 0f, 1f);
}
}
为 Unity
移植的VertexPositionNormalTexture 结构
public struct VertexPositionNormalTexture
{
public Vector3 Position;
public Vector3 Normal;
public Vector2 TextureCoordinate;
//public static readonly VertexDeclaration VertexDeclaration;
public VertexPositionNormalTexture(Vector3 position, Vector3 normal, Vector2 textureCoordinate)
{
this.Position = position;
this.Normal = normal;
this.TextureCoordinate = textureCoordinate;
}
public override int GetHashCode()
{
// TODO: FIc gethashcode
return 0;
}
public override string ToString()
{
return string.Format("{{Position:{0} Normal:{1} TextureCoordinate:{2}}}", new object[] { this.Position, this.Normal, this.TextureCoordinate });
}
public static bool operator ==(VertexPositionNormalTexture left, VertexPositionNormalTexture right)
{
return (((left.Position == right.Position) && (left.Normal == right.Normal)) && (left.TextureCoordinate == right.TextureCoordinate));
}
public static bool operator !=(VertexPositionNormalTexture left, VertexPositionNormalTexture right)
{
return !(left == right);
}
public override bool Equals(object obj)
{
if (obj == null)
{
return false;
}
if (obj.GetType() != base.GetType())
{
return false;
}
return (this == ((VertexPositionNormalTexture)obj));
}
}
移植的Unity工作不正常。没有贝壳，输出图像是平的。
这是 预期的 结果XNA（工作正常）：
但这是我在 Unity 中看到的（无壳）：
最终图像应该如下图所示，但我无法继续进行移植工作，因为基本实现无法在 Unity 中正常工作。
我的脚本public变量设置：
为什么移植后的Unity结果是平的？我错过了什么吗？
编辑：
我翻转了 UnitZ() 值并尝试反转网格顶点，但屏幕上没有任何内容。 这不太可能是问题所在。
Unity 正在对 material 进行批量优化。您可以在帧调试器中看到这一点。每个 DrawGeometry 调用都使用相同的 CurrentLayer 值。每次调用 DrawMesh 都需要使用属性块。 设置新的 material 会导致一些闪烁。
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
namespace foo {
public class FurBehavior : MonoBehaviour
{
public Material material;
public Vector3 pos = new Vector3(0f, 0.98f, -9.54f);
//simple camera for use in the game
private new Camera camera;
//texture containing fur data
public Texture2D furTexture;
//effect for fur shaders
//Effect furEffect;
//number of layers of fur
public int nrOfLayers = 40;
//total length of the hair
public float maxHairLength = 2.0f;
//density of hair
public float density = 0.2f;
//[Space(20)]
//public Vector3 dirWorldVal = new Vector3(0, -10, 0);
void Start()
{
this.transform.position = new Vector3(0f, 0.98f, -9.54f);
this.transform.rotation = Quaternion.Euler(0, 180, 0);
Initialize();
GenerateGeometry();
}
public void Update()
{
Draw();
}
void Initialize()
{
//Initialize the camera
camera = Camera.main;
//create the texture
furTexture = new Texture2D(256, 256, TextureFormat.ARGB32, false);
furTexture.wrapModeU = TextureWrapMode.Repeat;
furTexture.wrapModeV = TextureWrapMode.Repeat;
//furTexture.filterMode = FilterMode.Point;
//fill the texture
FillFurTexture(furTexture, density);
/*XNA's SurfaceFormat.Color is ARGB.
//https://gamedev.stackexchange.com/a/6442/98839*/
if (material.mainTexture != null)
{
material.mainTexture.wrapModeU = TextureWrapMode.Repeat;
material.mainTexture.wrapModeV = TextureWrapMode.Repeat;
// material.mainTexture.filterMode = FilterMode.Point;
}
}
bool firstDraw = true;
protected void Draw()
{
var pos = this.transform.position;
camera.backgroundColor = CornflowerBlue();
Matrix4x4 worldValue = Matrix4x4.Translate(pos);
Matrix4x4 viewValue = camera.projectionMatrix;
// viewValue = camera.worldToCameraMatrix;
Matrix4x4 projectionValue = camera.projectionMatrix;
material.SetMatrix("World", worldValue);
material.SetMatrix("View", viewValue);
material.SetMatrix("Projection", projectionValue); //Causes object to disappear
material.SetFloat("MaxHairLength", maxHairLength);
//if (firstDraw)
material.SetTexture("_MainTex", furTexture);
//furEffect.Begin();
for (int i = 0; i < nrOfLayers; i++)
{
var propertyBlock = new MaterialPropertyBlock();
var layer = (float)i / (float)nrOfLayers;
propertyBlock.SetFloat("CurrentLayer", layer);
propertyBlock.SetFloat("MaxHairLength", maxHairLength);
propertyBlock.SetColor("_TintColor", new Color(layer, layer, layer, layer));
DrawGeometry(propertyBlock);
}
if (firstDraw)
{
material.mainTexture.wrapModeU = TextureWrapMode.Repeat;
material.mainTexture.wrapModeV = TextureWrapMode.Repeat;
material.mainTexture.filterMode = FilterMode.Point;
}
if (firstDraw)
firstDraw = false;
}
void DrawGeometry(MaterialPropertyBlock props)
{
var rot = Quaternion.Euler(0, 180, 0);
Graphics.DrawMesh(verticesMesh, pos, rot, material, 0, camera, 0, props);
}
private VertexPositionNormalTexture[] verticesPText;
public Mesh verticesMesh;
private void GenerateGeometry()
{
var UnitZ = new Vector3(0, 0, 1);
var verticesPText = new VertexPositionNormalTexture[6];
verticesPText[5] = new VertexPositionNormalTexture(new Vector3(-10, 0, 0),
-UnitZ,
new Vector2(0, 0));
verticesPText[4] = new VertexPositionNormalTexture(new Vector3(10, 20, 0),
-UnitZ,
new Vector2(1, 1));
verticesPText[3] = new VertexPositionNormalTexture(new Vector3(-10, 20, 0),
-UnitZ,
new Vector2(0, 1));
verticesPText[2] = verticesPText[5];
verticesPText[1] = new VertexPositionNormalTexture(new Vector3(10, 0, 0),
-UnitZ,
new Vector2(1, 0));
verticesPText[0] = verticesPText[4];
}
Mesh VertexPositionNormalTextureToUnityMesh(VertexPositionNormalTexture[] vpnt)
{
Vector3[] vertices = new Vector3[vpnt.Length];
Vector3[] normals = new Vector3[vpnt.Length];
Vector2[] uvs = new Vector2[vpnt.Length];
int[] triangles = new int[vpnt.Length];
//Copy variables to create a mesh
for (int i = 0; i < vpnt.Length; i++)
{
vertices[i] = vpnt[i].Position;
normals[i] = vpnt[i].Normal;
uvs[i] = vpnt[i].TextureCoordinate;
triangles[i] = i;
}
Mesh mesh = new Mesh();
mesh.vertices = vertices;
mesh.normals = normals;
mesh.uv = uvs;
mesh.MarkDynamic();
mesh.triangles = triangles;
mesh.UploadMeshData(false);
return mesh;
}
private void FillFurTexture(Texture2D furTexture, float density)
{
//read the width and height of the texture
int width = furTexture.width;
int height = furTexture.height;
int totalPixels = width * height;
//an array to hold our pixels
Color32[] colors = new Color32[totalPixels];
//random number generator
System.Random rand = new System.Random();
//initialize all pixels to transparent black
for (int i = 0; i < totalPixels; i++)
colors[i] = TransparentBlack();
//compute the number of opaque pixels = nr of hair strands
int nrStrands = (int)(density * totalPixels);
//fill texture with opaque pixels
for (int i = 0; i < nrStrands; i++)
{
int x, y;
//random position on the texture
x = rand.Next(height);
y = rand.Next(width);
//put color (which has an alpha value of 255, i.e. opaque)
// colors[x * width + y] = new Color32((byte)255, (byte)x, (byte)y, (byte)255);
colors[x * width + y] = Gold();
}
//set the pixels on the texture.
furTexture.SetPixels32(colors);
// actually apply all SetPixels, don't recalculate mip levels
furTexture.Apply();
}
Color32 TransparentBlack()
{
//http://www.monogame.net/documentation/?page=P_Microsoft_Xna_Framework_Color_TransparentBlack
Color32 color = new Color32(0, 0, 0, 0);
return color;
}
Color32 Gold()
{
//http://www.monogame.net/documentation/?page=P_Microsoft_Xna_Framework_Color_Gold
Color32 color = new Color32(255, 215, 0, 255);
return color;
}
Color32 CornflowerBlue()
{
//http://www.monogame.net/documentation/?page=P_Microsoft_Xna_Framework_Color_CornflowerBlue
Color32 color = new Color32(100, 149, 237, 255);
return color;
}
public static Vector3 UnitZ()
{
return new Vector3(0f, 0f, 1f);
}
}
}
我还修改了着色器以可视化外壳。
// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with
'UnityObjectToClipPos(*)'
Shader "Programmer/Fur Shader"
{
Properties
{
_MainTex("Texture", 2D) = "white" {}
_TintColor("Tint Color", Color) = (1,1,1,1)
}
SubShader
{
Tags{ "Queue" = "Transparent" "RenderType" = "Transparent" }
LOD 100
//Blend SrcAlpha One
//Blend DstAlpha OneMinusSrcAlpha
Blend SrcAlpha OneMinusSrcAlpha
ZWrite Off
Cull Off
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
// make fog work
//#pragma multi_compile_fog
#include "UnityCG.cginc"
//In
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
//Out
struct v2f
{
float2 uv : TEXCOORD0;
UNITY_FOG_COORDS(1)
float4 vertex : SV_POSITION;
};
struct VertexShaderInput
{
float3 Position : POSITION0;
float3 Normal : NORMAL0;
float2 TexCoord : TEXCOORD0;
};
struct VertexShaderOutput
{
float4 Position : POSITION0;
float2 TexCoord : TEXCOORD0;
float4 Tint: COLOR1;
};
sampler2D _MainTex;
float4 _MainTex_ST;
//Test variable/delete after
float4 _TintColor;
//The variables
float4x4 World;
float4x4 View;
float4x4 Projection;
float CurrentLayer; //value between 0 and 1
float MaxHairLength; //maximum hair length
VertexShaderOutput vert(VertexShaderInput input)
{
VertexShaderOutput output;
float3 pos;
pos = input.Position + input.Normal * MaxHairLength * CurrentLayer;
//float4 worldPosition = mul(float4(pos, 1), World);
//float4 viewPosition = mul(worldPosition, View);
output.Position = UnityObjectToClipPos(pos);
output.TexCoord = input.TexCoord;
output.Tint = float4(CurrentLayer, CurrentLayer, 0, 1);
return output;
}
float4 frag(VertexShaderOutput i) : COLOR0
{
float4 t = tex2D(_MainTex, i.TexCoord) * i.Tint;
return t;//float4(t, i.x, i.y, 1);
}
ENDCG
}
}
}
这是在修改参数并稍微移动相机后的样子。