generate blur renderTexture

getBulurTex.cs

	public void GetBlurTex(RenderTexture targetTexture, int iteration, int ds){
		RenderTexture rt = targetTexture;
		float
			widthMod = 1f / (1f * (1 << ds));
		int
			rtW = rt.width,
			rtH = rt.height;
		for(int i = 0; i < iteration; i++){
			float iterationOffs = (float)i;
			bMat.SetVector("_Parameter", new Vector4(bSize * widthMod + iterationOffs, -bSize * widthMod - iterationOffs, 0, 0));
			
			RenderTexture rt2 = RenderTexture.GetTemporary(rtW, rtH, 0, rt.format);
			rt2.filterMode = FilterMode.Bilinear;
			Graphics.Blit(rt, rt2, bMat, 1);
			RenderTexture.ReleaseTemporary(rt);
			rt = rt2;
			
			rt2 = RenderTexture.GetTemporary(rtW, rtH, 0, rt.format);
			rt2.filterMode = FilterMode.Bilinear;
			Graphics.Blit(rt, rt2, bMat, 2);
			RenderTexture.ReleaseTemporary(rt);
			rt = rt2;
		}
	}