I wrote this simple terrain multitex shader a while ago and I can not seem to figure out how to blur the terrain at a distance...

Code:

---

 Texture entSkin1;
Texture mtlSkin1;
Texture mtlSkin2;
Texture mtlSkin3;

sampler2D tcolormap  = sampler_state
{
	Texture = (mtlSkin4);
	MinFilter = Linear;
	MagFilter = Linear;
	MipFilter = Linear;
};

sampler2D tgrass  = sampler_state
{
	Texture = (mtlSkin1);
	MinFilter = Linear;
	MagFilter = Linear;
	MipFilter = Linear;
};

sampler2D tdirt  = sampler_state
{
	Texture = (mtlSkin2);
	MinFilter = Linear;
	MagFilter = Linear;
	MipFilter = Linear;
};

sampler2D twater  = sampler_state
{
	Texture = (mtlSkin3);
	MinFilter = Linear;
	MagFilter = Linear;
	MipFilter = Linear;
};

struct PS_INPUT_STRUCT 
{ 
	float2 Tex : TEXCOORD0; 
	float3 light_angle : TEXCOORD1; 
};

struct PS_OUTPUT_STRUCT 
{
	float4 c : COLOR0;
};

float4 veccycle;
	PS_OUTPUT_STRUCT MyShader( PS_INPUT_STRUCT psInStruct, float4 inPos : POSITION)
{
	PS_OUTPUT_STRUCT Color;
	float4 Grass;
	float4 Dirt;
	float4 Water;
	
	Color.c = tex2D( tcolormap, psInStruct.Tex.xy);
	
	Grass = mul(tex2D( tgrass, mul(psInStruct.Tex.xy,800)),Color.c.g);
	Dirt = mul(tex2D( tdirt, mul(psInStruct.Tex.xy,500)),Color.c.r);
	Water = mul(tex2D( twater, mul(psInStruct.Tex.xy,120)),Color.c.b);
	
	Color.c=Grass+Dirt+Water;
	
	return Color;
}

technique PostProcess
{
	pass p0
	{
		PixelShader = compile ps_2_0 MyShader();
	}
}
 

---

Does anyone have any clue how I might go about doing this? You can use this if you want...

Thanks,
Brian