Aug
20
2016

Sprite Shader with Clip() *Discard pixels

An article by mgear Comments

Testing what happens if add clip(discard), remove transparency and remove color tint from default Sprite Shader..
Just wanted to see if there is big difference or not,
but seems like no huge difference on PC (asus laptop, gtx970m), unless you have thousands of sprites on screen (*will test on mobile later)

This thread says in mobile devices it might be worse performance to use Clip()..

Stats for test scene (20000 sprites overlapping, sprite texture: 128×128) *Using Unity 5.4.0p2

Sprite used (sprite mesh type: full rect)

Shader sources

Sprites/Clip

	// removed ColorTint, Added clip() based on alpha
	Shader "Sprites/Clip"
	{
	Properties
	{
	[PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
	[MaterialToggle] PixelSnap ("Pixel snap", Float) = 0
	_Cutoff ("AlphaCutoff", Range(0,1)) = 1
	}

	SubShader
	{
	Tags
	{
	"Queue"="Transparent"
	"IgnoreProjector"="True"
	"RenderType"="Transparent"
	"PreviewType"="Plane"
	"CanUseSpriteAtlas"="True"
	}

	Cull Off
	Lighting Off
	ZWrite Off
	Blend One OneMinusSrcAlpha

	Pass
	{
	CGPROGRAM
	#pragma vertex vert
	#pragma fragment frag
	#pragma target 2.0
	#pragma multi_compile _ PIXELSNAP_ON
	#include "UnityCG.cginc"

	struct appdata_t
	{
	float4 vertex : POSITION;
	float2 texcoord : TEXCOORD0;
	};

	struct v2f
	{
	float4 vertex : SV_POSITION;
	float2 texcoord : TEXCOORD0;
	};

	v2f vert(appdata_t IN)
	{
	v2f OUT;
	OUT.vertex = UnityObjectToClipPos(IN.vertex);
	OUT.texcoord = IN.texcoord;
	#ifdef PIXELSNAP_ON
	OUT.vertex = UnityPixelSnap (OUT.vertex);
	#endif
	return OUT;
	}

	sampler2D _MainTex;
	fixed _Cutoff;

	fixed4 frag(v2f IN) : SV_Target
	{
	fixed4 c = tex2D (_MainTex,IN.texcoord);
	clip(c.a-_Cutoff);
	c.rgb *= c.a;
	return c;
	}
	ENDCG
	}
	}
	}

view raw

Sprites_Clip.shader

hosted with ❤ by GitHub

Sprites/Clip-NoTransparency

	// removed ColorTint, Transparency, Added clip() based on alpha
	Shader "Sprites/Clip-NoTransparency"
	{
	Properties
	{
	[PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
	[MaterialToggle] PixelSnap ("Pixel snap", Float) = 0
	_Cutoff ("AlphaCutoff", Range(0,1)) = 1
	}

	SubShader
	{
	Tags
	{
	"Queue"="Geometry"
	"IgnoreProjector"="True"
	"RenderType"="Opaque"
	"PreviewType"="Plane"
	"CanUseSpriteAtlas"="True"
	}

	Cull Off
	Lighting Off
	ZWrite Off

	Pass
	{
	CGPROGRAM
	#pragma vertex vert
	#pragma fragment frag
	#pragma target 2.0
	#pragma multi_compile _ PIXELSNAP_ON
	#include "UnityCG.cginc"

	struct appdata_t
	{
	float4 vertex : POSITION;
	float2 texcoord : TEXCOORD0;
	};

	struct v2f
	{
	float4 vertex : SV_POSITION;
	float2 texcoord : TEXCOORD0;
	};

	v2f vert(appdata_t IN)
	{
	v2f OUT;
	OUT.vertex = UnityObjectToClipPos(IN.vertex);
	OUT.texcoord = IN.texcoord;
	#ifdef PIXELSNAP_ON
	OUT.vertex = UnityPixelSnap (OUT.vertex);
	#endif
	return OUT;
	}

	sampler2D _MainTex;
	fixed _Cutoff;

	fixed4 frag(v2f IN) : SV_Target
	{
	fixed4 c = tex2D (_MainTex, IN.texcoord);
	clip(c.a-_Cutoff);
	//if (c.a<_Cutoff) discard;
	return c;
	}
	ENDCG
	}
	}
	}