Я пытаюсь реализовать мех в Unity с помощью техники Shells .Техника Fins намеренно опущена, потому что я хочу, чтобы она работала на недорогих мобильных устройствах (в основном на устройствах Android), и для этого требуется OpenGL ES 3.0 и выше, в то время как Техника оболочек требует только OpenGL ES 2.0 .
Существует пример использования технологии Shell, основанной на XNA, и я попытался перенести ее в Unity, но она не сработала. Здесь - статья с проектом XNA.
Шейдер XNA :
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();
}
}
Сценарий XNA C #, управляющий шейдером:
/// <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);
}
}
}
Я осторожно портировал шейдер и скрипт управления построчно в Unity.
Портированный шейдер Unity :
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
}
}
}
Портированный Unity C # скрипт, управляющий шейдером:
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);
}
}
Портированная VertexPositionNormalTexture структура для Unity
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));
}
}
Портированная работа Unity не работает должным образом.Оболочек нет, а выходное изображение плоское.
Это ожидаемый результат в XNA (Работает нормально):
Но это то, что я вижу в Unity (без снарядов):
Окончательное изображение должно выглядеть примерно так, как показано ниже, но я не могу продолжить работу по портированию, поскольку базовая реализация не работает в Unity должным образом.
Настройки открытых переменных моего скрипта:
Почему результат переноса Unity плоский?Я что-то пропустил?
РЕДАКТИРОВАТЬ:
Лев упомянул о возможной backface проблема, потому что Unity использует левшусистема координат, в то время как XNA использует правую систему координат.
Я перевернул значение UnitZ(), а также попытался повернуть вершины сетки, но на экране ничего не было. Это вряд ли проблема.