Intersection Shader intersects with Intersection Shader!
Hi everyone,
I would like to write a shader which can be applied to two objects. Where the two objects intersect, an unlit red area should be drawn. How can I do this please?
I already have the shader below, but it doesn't seem to work if you have two objects with the same shader applied:
//Highlights intersections with other objects
Shader "Custom/IntersectionHighlights"
{
Properties
{
_RegularColor("Main Color", Color) = (1, 1, 1, .5) //Color when not intersecting
_HighlightColor("Highlight Color", Color) = (1, 1, 1, .5) //Color when intersecting
_HighlightThresholdMax("Highlight Threshold Max", Float) = 1 //Max difference for intersections
}
SubShader
{
Tags { "Queue" = "Transparent" "RenderType"="Transparent" }
Pass
{
Blend SrcAlpha OneMinusSrcAlpha
ZWrite Off
Cull Off
CGPROGRAM
#pragma target 3.0
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
uniform sampler2D _CameraDepthTexture; //Depth Texture
uniform float4 _RegularColor;
uniform float4 _HighlightColor;
uniform float _HighlightThresholdMax;
struct v2f
{
float4 pos : SV_POSITION;
float4 projPos : TEXCOORD1; //Screen position of pos
};
v2f vert(appdata_base v)
{
v2f o;
o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
o.projPos = ComputeScreenPos(o.pos);
return o;
}
half4 frag(v2f i) : COLOR
{
float4 finalColor = _RegularColor;
//Get the distance to the camera from the depth buffer for this point
float sceneZ = LinearEyeDepth (tex2Dproj(_CameraDepthTexture,
UNITY_PROJ_COORD(i.projPos)).r);
//Actual distance to the camera
float partZ = i.projPos.z;
//If the two are similar, then there is an object intersecting with our object
float diff = (abs(sceneZ - partZ)) /
_HighlightThresholdMax;
if(diff <= 1)
{
finalColor = lerp(_HighlightColor,
_RegularColor,
float4(diff, diff, diff, diff));
}
half4 c;
c.r = finalColor.r;
c.g = finalColor.g;
c.b = finalColor.b;
c.a = finalColor.a;
return c;
}
ENDCG
}
}
FallBack "VertexLit"
}
This doesn't work because objects with ZWrite off (i.e. semitransparent objects) do not write to the depth buffer.
Your answer
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