Just added a new colour cycle effect transparent Unity shader to the free shaders collection. This shader can be used to overlay a y-axis colour cycle effect over a texture
The code for the shader is shown below:
[sourcecode language=”js”]
Shader "Unlit/ColourCycleTexture"
{
Properties
{
_MainTex("Color (RGB) Alpha (A)", 2D) = "white" {}
_WaveSpeed ("WaveSpeed", Range(-1000, 1000)) = 20
_Frequency ("Frequency", Range(0, 100)) = 10
_Amplitude ("Amplitude", Range(0, 3)) = 0.02
_RedScale("Red Scale", Range(0, 3)) = 1
_GreenScale("Green Scale", Range(0, 3)) = 1
_BlueScale("Blue Scale", Range(0, 3)) = 1
}
SubShader
{
Tags{ "Queue" = "Transparent" "RenderType" = "Transparent" }
Blend SrcAlpha OneMinusSrcAlpha
LOD 100
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f
{
float2 uv : TEXCOORD0;
float4 vertex : SV_POSITION;
};
sampler2D _MainTex;
float4 _MainTex_ST;
fixed _Frequency;
fixed _WaveSpeed;
fixed _Amplitude;
fixed _RedScale;
fixed _GreenScale;
fixed _BlueScale;
v2f vert (appdata v)
{
v2f o;
o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
return o;
}
fixed4 frag (v2f i) : SV_Target
{
fixed2 uvs = i.uv;
fixed4 col = tex2D(_MainTex, uvs);
fixed d = sin(uvs.y * _Frequency + _Time * _WaveSpeed) * _Amplitude;
col.r += d * _RedScale;
col.g += d * _GreenScale;
col.b += d * _BlueScale;
return col;
}
ENDCG
}
}
}
[/sourcecode]
The shader works by adjusting the colour of the texel pulled from the texture applying a wave effect which is then scaled by red, green and blue scaling factors which can be used to change the colour of the overlaid effect. Here are a few parameters to try:
Produce a nice upwards red scroll effect:
Wave Speed – -150
Frequency – -20
Amplitude – -1
Red Scale – 0
Green Scale – 0.4
Blue Scale – 0
Produce a slow flash:
Wave Speed – 150
Frequency – 1
Amplitude – 1
Red Scale – 0
Green Scale – 0.4
Blue Scale – 0
You may need to adjust the red, green and blue scaling factors to match the colour of your texture.