Question

我试图用置换贴图实现2D失真效果，我将在运行时通过组合这样的图像来创建。 Link to Displacementmap

但是由于（255,255，x）等于无位移的事实，我无法将这些图像与现有的BlendModes结合起来。

所以我想将信息存储在RGBA（对于x +，y +，x-，y-）的颜色中，但渲染到RenderTarget2D会将每个颜色设置为Alpha = 0到Black，Alpha = 0。是否有更好的方法来组合位移图或防止这种行为的方法？

Answer 1

您可以像这样使用自定义着色器

/* Variables */

float OffsetPower;

texture TextureMap; // texture 0
sampler2D textureMapSampler = sampler_state
{
    Texture = (TextureMap);
    MagFilter = Linear;
    MinFilter = Linear;
    AddressU = Clamp;
    AddressV = Clamp;
};

texture DisplacementMap; // texture 1
sampler2D displacementMapSampler = sampler_state
{
    Texture = (DisplacementMap);
    MagFilter = Linear;
    MinFilter = Linear;
    AddressU = Clamp;
    AddressV = Clamp;
};

/* Vertex shader output structures */

struct VertexShaderOutput
{
    float4 Position : position0;
    float2 TexCoord : texcoord0;
};

/* Pixel shaders */

float4 PixelShader1(VertexShaderOutput pVertexOutput) : color0
{
    float4 displacementColor = tex2D(displacementMapSampler, pVertexOutput.TexCoord);
    float offset = (displacementColor.g - displacementColor.r) * OffsetPower;

    float2 newTexCoord = float2(pVertexOutput.TexCoord.x + offset, pVertexOutput.TexCoord.y + offset);
    float4 texColor = tex2D(textureMapSampler, newTexCoord);

    return texColor;
}

/* Techniques */

technique Technique1
{
    pass Pass1
    {
        PixelShader = compile ps_2_0 PixelShader1();
    }
}

在LoadContent方法中：

this.textureMap = this.Content.Load<Texture2D>(@"Textures/creeper");
this.displacementMap = this.Content.Load<Texture2D>(@"Textures/displacement_map");
this.displacementEffect = this.Content.Load<Effect>(@"Effects/displacement");

在Draw方法中：

Rectangle destinationRectangle = new Rectangle(0, 0, this.GraphicsDevice.Viewport.Width, this.GraphicsDevice.Viewport.Height);

this.displacementEffect.Parameters["OffsetPower"].SetValue(0.5f);
this.displacementEffect.Parameters["DisplacementMap"].SetValue(this.displacementMap);

this.spriteBatch.Begin(SpriteSortMode.Immediate, BlendState.AlphaBlend, null, null, null, this.displacementEffect);
this.spriteBatch.Draw(this.textureMap, destinationRectangle, Color.White);
this.spriteBatch.End();

Result

c＃XNA 2D失真效果

1 个答案: