Tiling/Pattern Filling a Sprite

Questions & Answers
1

I’ve spent hours beating my head against the wall so I thought maybe asking here could help.

I’m wondering if there’s a quick way to apply a pattern/texture to a sprite. I wanted to texture a 2D white sprite circle (not a sphere) with a repeating 2x2 pattern, resulting in something like this picture:
alt text

Everything I’ve done so far seems to suggest that this isn’t readily possible. I hope that’s not the case, because it’ll make everything messier. Thanks for any help you can provide.

2

Here is a “stipple/screen door transparency” shader that does what you need.

Alex Ocias Blog

Download link

Shader "Ocias/Diffuse (Stipple Transparency)" {
Properties {
    _MainTex ("Base (RGB)", 2D) = "white" {}
    _Transparency ("Transparency", Range(0,1)) = 1.0
}
SubShader {
    Tags { "RenderType"="Opaque" }
    LOD 150
CGPROGRAM
#pragma surface surf Lambert noforwardadd
sampler2D _MainTex;
struct Input {
    float2 uv_MainTex;
    float4 screenPos;
};
half _Transparency;
void surf (Input IN, inout SurfaceOutput o) {
    fixed4 c = tex2D(_MainTex, IN.uv_MainTex);
    o.Albedo = c.rgb;
    o.Alpha = c.a;
    // Screen-door transparency: Discard pixel if below threshold.
    float4x4 thresholdMatrix =
    {  1.0 / 17.0,  9.0 / 17.0,  3.0 / 17.0, 11.0 / 17.0,
      13.0 / 17.0,  5.0 / 17.0, 15.0 / 17.0,  7.0 / 17.0,
       4.0 / 17.0, 12.0 / 17.0,  2.0 / 17.0, 10.0 / 17.0,
      16.0 / 17.0,  8.0 / 17.0, 14.0 / 17.0,  6.0 / 17.0
    };
    float4x4 _RowAccess = { 1,0,0,0, 0,1,0,0, 0,0,1,0, 0,0,0,1 };
    float2 pos = IN.screenPos.xy / IN.screenPos.w;
    pos *= _ScreenParams.xy; // pixel position
    clip(_Transparency - thresholdMatrix[fmod(pos.x, 4)] * _RowAccess[fmod(pos.y, 4)]);
}
ENDCG
}
Fallback "Mobile/VertexLit"
}
3

run this:

	int i;
	int i2;
	bool b;
	public int size = 64;
	public int center;

	public Texture2D image;

	void Start(){
		center=(int)(size*.5f);
    image = new Texture2D (size, size);
	image.filterMode = FilterMode.Point;
     i = image.width;
		while(i>0){i--;b=!b;
			i2=image.height;
			while(i2>0){i2--;b=!b;
				if(dist(i,i2)<center){
				if(b){image.SetPixel(i,i2,Color.black);}
				 else{image.SetPixel(i,i2,Color.white);}
				}
				else{image.SetPixel(i,i2,Color.clear);}}}
		image.Apply ();
	}
	public float dist (int x, int y){
        int f1 = (center - x) * (center - x);
		int f2 = (center - y) * (center - y);
		
        return Mathf.Sqrt(f1+f2);}

	void OnGUI(){
		GUI.DrawTexture(new Rect(10,10,400,400),image);
	}