单色高斯模糊效果结果为纯色纹理2D

Question

我正在开发一个单一游戏的游戏，最近从XNA转换过来，我的模糊效果停止了。在成功运行它并且没有错误（并且不改变任何代码逻辑）之后，应该模糊的图像变成纯色。

图片： 之前：      之后（XNA）：      之后（monogame）：     

这是我的模糊功能的逻辑（在VB中）： `

Public Shared Function blurImage(p As player, img As Texture2D, sb As SpriteBatch, Optional radius As Integer = 2, Optional amount As Single = 1.0F) As Texture2D

Dim sigma As Single = radius / amount : Dim kernel As Single() = New Single(radius * 2) {} : Dim index As Integer = 0
Dim twoSigmaSquare As Single = 2.0F * sigma * sigma : Dim sigmaRoot As Single = CSng(Math.Sqrt(twoSigmaSquare * Math.PI))
Dim offsetsHoriz As Vector2() = New Vector2(radius * 2) {} : Dim offsetsVert As Vector2() = New Vector2(radius * 2) {}
Dim effect As Effect = content.Load(Of Effect)("Effects\GaussianBlur")

For i As Integer = -radius To radius
    index = i + radius
    offsetsHoriz(index) = New Vector2(i * 1.0F / img.Width, 0F)
    offsetsVert(index) = New Vector2(0F, i * 1.0F / img.Height)
Next

Dim total As Single = 0F : Dim distance As Single = 0F : index = 0
For i As Integer = -radius To radius
    distance = i * i : index = i + radius
    kernel(index) = CSng(Math.Exp(-distance / twoSigmaSquare)) / sigmaRoot
    total += kernel(index)
Next
For i As Integer = 0 To kernel.Length - 1 : kernel(i) /= total : Next

Dim renderTarget1 As Texture2D = New RenderTarget2D(Game.graphics.GraphicsDevice, img.Width, img.Height, False, Game.graphics.GraphicsDevice.PresentationParameters.BackBufferFormat, DepthFormat.None)
Dim renderTarget2 As Texture2D = New RenderTarget2D(Game.graphics.GraphicsDevice, img.Width, img.Height, False, Game.graphics.GraphicsDevice.PresentationParameters.BackBufferFormat, DepthFormat.None)

Dim outputTexture As Texture2D = Nothing
Dim srcRect As New Rectangle(0, 0, img.Width, img.Height)
Dim destRect1 As New Rectangle(0, 0, renderTarget1.Width, renderTarget1.Height)
Dim destRect2 As New Rectangle(0, 0, renderTarget2.Width, renderTarget2.Height)
Game.graphics.GraphicsDevice.SetRenderTarget(renderTarget1)

effect.CurrentTechnique = effect.Techniques("GaussianBlur")
effect.Parameters("weights").SetValue(kernel)
effect.Parameters("colorMapTexture").SetValue(img)
effect.Parameters("offsets").SetValue(offsetsHoriz)

sb.Begin(0, BlendState.Opaque, Nothing, Nothing, Nothing, effect)
sb.Draw(img, destRect1, Color.White)
sb.[End]()

Game.graphics.GraphicsDevice.SetRenderTarget(renderTarget2)
outputTexture = DirectCast(renderTarget1, Texture2D)

effect.Parameters("colorMapTexture").SetValue(outputTexture)
effect.Parameters("offsets").SetValue(offsetsVert)

sb.Begin(0, BlendState.Opaque, Nothing, Nothing, Nothing, effect)
sb.Draw(outputTexture, destRect2, Color.White)
sb.End()

Game.graphics.GraphicsDevice.SetRenderTarget(Nothing)
outputTexture = DirectCast(renderTarget2, Texture2D)

Return outputTexture
End Function

`

以下是guassian模糊效果文件中包含的代码： `

#define RADIUS  2
#define KERNEL_SIZE (RADIUS * 2 + 1)

//-----------------------------------------------------------------------------
// Globals.
//-----------------------------------------------------------------------------

float weights[KERNEL_SIZE];
float2 offsets[KERNEL_SIZE];

//-----------------------------------------------------------------------------
// Textures.
//-----------------------------------------------------------------------------

texture colorMapTexture;

sampler2D colorMap = sampler_state
{
    Texture = <colorMapTexture>;
    MipFilter = Linear;
    MinFilter = Linear;
    MagFilter = Linear;
};

//-----------------------------------------------------------------------------
// Pixel Shaders.
//-----------------------------------------------------------------------------

float4 PS_GaussianBlur(float2 texCoord : TEXCOORD) : COLOR0
{
    float4 color = float4(0.0f, 0.0f, 0.0f, 0.0f);

    for (int i = 0; i < KERNEL_SIZE; ++i)
        color += tex2D(colorMap, texCoord + offsets[i]) * weights[i];

    return color;
}

//-----------------------------------------------------------------------------
// Techniques.
//-----------------------------------------------------------------------------

technique GaussianBlur
{
    pass
    {
        PixelShader = compile ps_4_0_level_9_1 PS_GaussianBlur();
    }
}

`