I want to create a “wipe” effect, such as is often done by using a black and white gradient texture and changing the cutoff value of the cutout shader to create the desired animation. However, this only works on very basic UV maps; as soon as you have a real world scenario, you’re not going to have a correct wipe using this method.
I’m still very new to shaders, but I adapted a custom cutout shader that I happened across to have a “Height” property, which can be used to create a cut off based on the world position of the pixels. (if the object starts at y = 0, but for my specific case this is always true)
Shader "Animations/VerticalFadeInCutout"
{
Properties
{
_Color ("Main Color", Color) = (1,1,1,1)
_MainTex ("Base (RGB) Trans (A)", 2D) = "white" {}
_Cutoff ("Alpha cutoff", Range(0,1)) = 0.5
_Height("Height", Float) = 1
}
SubShader
{
Tags {"Queue"="AlphaTest" "IgnoreProjector"="True" "RenderType"="TransparentCutout"}
LOD 200
Cull Off
CGPROGRAM
#pragma surface surf Lambert alphatest:_Cutoff
sampler2D _MainTex;
fixed4 _Color;
float _Height;
struct Input
{
float2 uv_MainTex;
float3 worldPos;
};
void surf (Input IN, inout SurfaceOutput o)
{
fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
o.Albedo = c.rgb;
o.Alpha = (_Height - IN.worldPos.y) - (_Height / 2) + 0.5;
}
ENDCG
}
Fallback "Transparent/Cutout/Diffuse"
}
Turning the object transparent works just fine this way, however the shadow is still being cast, both on the transparent bits of the mesh itself and on the geometry behind it. If I change the color in the inspector directly though, the shadows do get removed. I reckon I’m doing something wrong here, so I’d really appreciate a hand in this matter.
Thanks!
