[SOLVED]Billboard sprite shader

Questions & Answers
1

Hi guys !

I’m trying to modify the “Sprite - Default” shader (from the builtin_shaders-5.5.0f3) with another shader that I found to make my sprite become billboards.

Currently the billboarding part of the code is operating well (sprites are facing the camera) but I got some weird “disappearing”… Some sprites are blinking or disappearing when I move the camera (even in viewport).

No doubt it comes from the part of code I’ve implemented but since I’m fairly new in shader programming, I have absolutely no clue on how to solve this.

here’s the shader :

Shader "Custom/Sprite_Billboard" {
	Properties
	{
		[PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
		_Color ("Tint", Color) = (1,1,1,1)
		//_Time ("Time", Float) = 0
		[MaterialToggle] PixelSnap ("Pixel snap", Float) = 0
	}

	SubShader
	{
		Tags
		{ 
			"Queue"="Transparent"
			"SortingLayer"="Resources_Sprites" 
			"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
			#pragma multi_compile _ ETC1_EXTERNAL_ALPHA
			#include "UnityCG.cginc"

//			uniform Float _Time;

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

			struct v2f
			{
				float4 vertex   : SV_POSITION;
				fixed4 color    : COLOR;
				float2 texcoord  : TEXCOORD0;
				UNITY_VERTEX_OUTPUT_STEREO
			};
			
			fixed4 _Color;

			v2f vert(appdata_t IN)
			{
				v2f OUT;
				UNITY_SETUP_INSTANCE_ID(IN);
				UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(OUT);
//				OUT.vertex = UnityObjectToClipPos(IN.vertex);
				OUT.texcoord = IN.texcoord;
				OUT.color = IN.color * _Color;
			//	#ifdef PIXELSNAP_ON

				OUT.vertex = mul(UNITY_MATRIX_P, 
             	mul(UNITY_MATRIX_MV, float4(0.0, 0.0, 0.0, 1.0))
            	- float4(IN.vertex.y, IN.vertex.x, 0.0, 0.0)
             	* float4(0.1, 0.1, 1.0, 1.0));

//				OUT.vertex = UnityPixelSnap (OUT.vertex);
			//	#endif

				return OUT;
			}

			sampler2D _MainTex;
			sampler2D _AlphaTex;

			fixed4 SampleSpriteTexture (float2 uv)
			{
				fixed4 color = tex2D (_MainTex, uv);

#if ETC1_EXTERNAL_ALPHA
				// get the color from an external texture (usecase: Alpha support for ETC1 on android)
				color.a = tex2D (_AlphaTex, uv).r;
#endif //ETC1_EXTERNAL_ALPHA

				return color;
			}

			fixed4 frag(v2f IN) : SV_Target
			{
				fixed4 c = SampleSpriteTexture (IN.texcoord) * IN.color;
				c.rgb *= c.a;
				return c;
			}
		ENDCG
		}
	}
}

Does anyone have a clue on how I can solve this problem ?

2

Problem solved !
I just needed to add “DisableBatching” = “True” in Tags section :wink: