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Control materials opacity.
Im doing a game where I need to control the opacity of a material when a object is beetween the character and the camera.
I found this shader:
Shader "Tinted Alpha Blend" {
Properties {
_Color ("Tint (A = Opacity)", Color) = (1,1,1,1)
_MainTex ("Texture (A = Transparency)", 2D) = ""
}
SubShader {
Tags {Queue = Transparent}
ZWrite On
Blend SrcAlpha OneMinusSrcAlpha
Pass {
SetTexture[_MainTex] {
ConstantColor [_Color]
Combine texture * constant
}
}
}
}
But then I realised that it isn't affected by lights.
Can anyone give me a hand? (Keep in mind I don't understand anything about shaders yet)
Answer by azmat786n · Dec 06, 2012 at 08:08 PM
right click in project select create > shader then rename it opacity edit using mono develop erase all copy paste below code into shader save it
go to material select shader > Custom-->opacity i hope this is helpful.
Shader "Custom/Opacity" { Properties { _BumpAmt ("Distortion", range (0,128)) = 10 _MainTex ("Tint Color (RGB)", 2D) = "white" {} _BumpMap ("Normalmap", 2D) = "bump" {} }
Category {
// We must be transparent, so other objects are drawn before this one.
Tags { "Queue"="Transparent" "RenderType"="Opaque" }
SubShader {
// This pass grabs the screen behind the object into a texture.
// We can access the result in the next pass as _GrabTexture
GrabPass {
Name "BASE"
Tags { "LightMode" = "Always" }
}
// Main pass: Take the texture grabbed above and use the bumpmap to perturb it
// on to the screen
Pass {
Name "BASE"
Tags { "LightMode" = "Always" }
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma fragmentoption ARB_precision_hint_fastest
#include "UnityCG.cginc"
struct appdata_t {
float4 vertex : POSITION;
float2 texcoord: TEXCOORD0;
};
struct v2f {
float4 vertex : POSITION;
float4 uvgrab : TEXCOORD0;
float2 uvbump : TEXCOORD1;
float2 uvmain : TEXCOORD2;
};
float _BumpAmt;
float4 _BumpMap_ST;
float4 _MainTex_ST;
v2f vert (appdata_t v)
{
v2f o;
o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
#if UNITY_UV_STARTS_AT_TOP
float scale = -1.0;
#else
float scale = 1.0;
#endif
o.uvgrab.xy = (float2(o.vertex.x, o.vertex.y*scale) + o.vertex.w) * 0.5;
o.uvgrab.zw = o.vertex.zw;
o.uvbump = TRANSFORM_TEX( v.texcoord, _BumpMap );
o.uvmain = TRANSFORM_TEX( v.texcoord, _MainTex );
return o;
}
sampler2D _GrabTexture;
float4 _GrabTexture_TexelSize;
sampler2D _BumpMap;
sampler2D _MainTex;
half4 frag( v2f i ) : COLOR
{
// calculate perturbed coordinates
half2 bump = UnpackNormal(tex2D( _BumpMap, i.uvbump )).rg; // we could optimize this by just reading the x & y without reconstructing the Z
float2 offset = bump * _BumpAmt * _GrabTexture_TexelSize.xy;
i.uvgrab.xy = offset * i.uvgrab.z + i.uvgrab.xy;
half4 col = tex2Dproj( _GrabTexture, UNITY_PROJ_COORD(i.uvgrab));
half4 tint = tex2D( _MainTex, i.uvmain );
return col * tint;
}
ENDCG
}
}
// ------------------------------------------------------------------
// Fallback for older cards and Unity non-Pro
SubShader {
Blend DstColor Zero
Pass {
Name "BASE"
SetTexture [_MainTex] { combine texture }
}
}
}
}
Thanks. Looks great, but still it doesn´t recive shadows (or at less I can't notice them) and I need a way to control the opacity level.
Answer by Bunny83 · Dec 07, 2012 at 01:07 AM
Transparent shaders never cast or receive shadows. The only one is the cut-out shader which doesn't have transparency, just areas which are cut out completely.
See this thread for more details:
http://forum.unity3d.com/threads/9909-No-shadows-visible-on-Transparency-Shaders-!!
You should also be clearer in your question. Light and shadows are two very different things in gameengines. Shadows have to be generated. They aren't simply a result of blocking light (which would be very hard to detect).