diff --git a/Src/Graphics/New3D/R3DShaderCommon.h b/Src/Graphics/New3D/R3DShaderCommon.h
index df392ea..f1b39f1 100644
--- a/Src/Graphics/New3D/R3DShaderCommon.h
+++ b/Src/Graphics/New3D/R3DShaderCommon.h
@@ -263,6 +263,7 @@ vec4 textureR3D(usampler2D texSampler, ivec2 wrapMode, ivec2 texSize, ivec2 texP
 	}
 	else
 	{
+		// if fLevel is 0, no need to mix with next mipmap level; slight performance boost
 		return texBiLinear(texSampler, wrapMode, vec2(texSize0), texPos0, texCoord);
 	}
 }