Render a object on top of another.

Question

I have two objects in the scene.

alt text

How can I make it, that the red Object is always seen by the camera? Here, red is seen by the camera with red color.

I read somewhere, that is possible with the depth of a second camera. But I want a shader.

I found, that it must be possible with a tag in a shader like this here:

 Tags { "Queue" = "Overlay" }

or with this:

 Tags { "Queue" = "Geometry+1" }

But it's not working with these tags.

Here the full shader code:

 Shader "Custom/ObjectControlAxisZ" {
     Properties {
         _MainTex ("Base (RGB)", 2D) = "white" {}
     }
     SubShader {
         Tags {  "Queue" = "Geometry+1" "RenderType"="Opaque" }
         LOD 200
         
         CGPROGRAM
         #pragma surface surf Lambert
 
         sampler2D _MainTex;
 
         struct Input {
             float2 uv_MainTex;
         };
 
         void surf (Input IN, inout SurfaceOutput o) {
             half4 c = tex2D (_MainTex, IN.uv_MainTex);
             o.Albedo = c.rgb;
             o.Alpha = c.a;
         }
         ENDCG
     } 
     FallBack "Diffuse"
 }

Answer 1

Best Answer

Answer by tanoshimi · Jul 04, 2015 at 11:53 AM

You want the ZTest Always tag. (And possibly also ZWrite Off).

http://docs.unity3d.com/Manual/SL-CullAndDepth.html

Add comment · Show 2 · Share

dixonalex · Jul 24, 2019 at 06:46 AM 0

Share

Is that offer us a 4D effect? I can see the diffuse function has 4 vertices. I think we are using 4 vertices for 4D object, aren't we?

tgrushka · Jul 05, 2020 at 04:00 AM 0

Share

There is a more helpful answer by lolmaster2 below with a code example with twice as many upvotes. Why is this one still marked as the best answer?

Answer 2

1 - In the menu: Assets -> Create -> Shader -> Standard Surface Shader

2 - Name it AlwaysOnTop

3 - Open it and replace the content with this code

4 - In the Inspector goto your material and choose your new shader: Custom -> AlwaysOnTop

You can also use transparency by changing the alpha value of the "Text Color" parameter of the material (the shader is just a modified version of the 3D Text Shader)

 Shader "Custom/AlwaysOnTop" {
     Properties {
         _MainTex ("Font Texture", 2D) = "white" {}
         _Color ("Text Color", Color) = (1,1,1,1)
         
         _StencilComp ("Stencil Comparison", Float) = 8
         _Stencil ("Stencil ID", Float) = 0
         _StencilOp ("Stencil Operation", Float) = 0
         _StencilWriteMask ("Stencil Write Mask", Float) = 255
         _StencilReadMask ("Stencil Read Mask", Float) = 255
 
         _ColorMask ("Color Mask", Float) = 15
     }
 
     SubShader {
 
         Tags 
         {
             "Queue"="Transparent"
             "IgnoreProjector"="True"
             "RenderType"="Transparent"
             "PreviewType"="Plane"
         }
         
         Stencil
         {
             Ref [_Stencil]
             Comp [_StencilComp]
             Pass [_StencilOp] 
             ReadMask [_StencilReadMask]
             WriteMask [_StencilWriteMask]
         }
         
         Lighting Off 
         Cull Off 
         ZTest Off
         ZWrite Off 
         Blend SrcAlpha OneMinusSrcAlpha
         ColorMask [_ColorMask]
 
         Pass 
         {
             CGPROGRAM
             #pragma vertex vert
             #pragma fragment frag
 
             #include "UnityCG.cginc"
 
             struct appdata_t {
                 float4 vertex : POSITION;
                 fixed4 color : COLOR;
                 float2 texcoord : TEXCOORD0;
             };
 
             struct v2f {
                 float4 vertex : SV_POSITION;
                 fixed4 color : COLOR;
                 float2 texcoord : TEXCOORD0;
             };
 
             sampler2D _MainTex;
             uniform float4 _MainTex_ST;
             uniform fixed4 _Color;
             
             v2f vert (appdata_t v)
             {
                 v2f o;
                 o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
                 o.color = v.color * _Color;
                 o.texcoord = TRANSFORM_TEX(v.texcoord, _MainTex);
 #ifdef UNITY_HALF_TEXEL_OFFSET
                 o.vertex.xy += (_ScreenParams.zw-1.0)*float2(-1,1);
 #endif
                 return o;
             }
 
             fixed4 frag (v2f i) : SV_Target
             {
                 fixed4 col = i.color;
                 col.a *= tex2D(_MainTex, i.texcoord).a;
                 clip (col.a - 0.01);
                 return col;
             }
             ENDCG 
         }
     }
 }

Answer 3

Answer by conscienceawake · Nov 06, 2018 at 10:02 AM

can anyone hep , i have a problem i need to solve

sprite 1 = is an overlay is in front of everything sprite 2 = buildings, are behind the overlay sprite 3 = stars, are behind the buildings

i want to render sprite 3 on top of sprite 1, but i want to render sprite 3 behind sprite 2 and sprite 2 must render behind sprite 1.

any Ideas :(

Add comment · Show 1 · Share

LostOter · Jul 24, 2019 at 06:10 AM 0

Share

assu$$anonymous$$g sprite 2 is completely opaque then this can be achieved with a sprite mask. Sprite3 is in front of everything, Sprite1 is behind Sprite3, Sprite2 is behind Sprite1, Sprite2 has a sprite$$anonymous$$ask component blocking out parts of Sprite3.

Render a object on top of another.

3 Replies

Your answer

Follow this Question

Related Questions