koobas.hobune.stream
How to access to a variable in shader from a script ?
Hi, I have a variable to control a value of a something in my shader. I need to control and change that value from a script.
The variable is "fovSize". Bellow my shader :
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
static const float fovSize = 0.1;
And
fragmentOutput frag(v2f i)
{
fragmentOutput o;
o.zvalue = 0.0;
o.color = (1, 1, 1, 1);
if ((i.posInObjectCoords.y < -fovSize || i.posInObjectCoords.y > fovSize) ||
(i.posInObjectCoords.x < -fovSize || i.posInObjectCoords.x > fovSize))
{
o.zvalue = 1.0;
}
return o;
}
But it looks like I can't use that kind of code in my script because its not in the Properties :
rend.material.SetFloat("_FovSize", fovSize);
I tried to declare in the Properties : _FovSize("fovSize", Float) = 1
And to use : if (i.posInObjectCoords.y < -_FovSize)
But doesn't work.
Any idea ?
If you want to control a shader value from a script you don't need to declare it in the properties. Just declare it like this.
// Shader
uniform float _myValue;
In your script use Shader.SetGlobalFloat or Material.SetFloat depending on you use case.
// Script
public float myValue = 1.0f;
Shader.SetGlobalFloat("_myValue", myValue);
I would also suggest you to take a look at those chapters Accessing shader properties in Cg/HLSL and MaterialPropertyBlock.
Thank you,
Why don't you declare it like this :
_FovSize("fovSize", Float) = 1.0
What is the difference ? And why do you use uniform ?
The declaration you showed is used to expose the properties in the inspector.
// Visible in the material inspector
_FovSize("fovSize", Float) = 1.0
float _FovSize;
// Not visible in the material inspector
float _FovSize;
the uniform attribute is used when you want to control the value from the application or if you prefer from "outside" the shader.
Ok, So first I tried to do every thing in the shader but I have two new errors :
Shader error in 'FadeBlack': Parse error: syntax error, unexpected TO$$anonymous$$_FLOAT, expecting '(' at line 6
Shader warning in 'FadeBlack': Shader is not supported on this GPU (none of subshaders/fallbacks are suitable)
I declare _fovSize in the Properties, define it in the Pass and affect a value in fragmentOutput to use it.
I post my complete shader bellow :
Shader "Custom/FadeBlack"
{ Properties
{
uniform float _fovSize;
}
SubShader
{
Tags{ "Queue" = "Geometry+5" "IgnoreProjector" = "True" "RenderType" = "Opaque" }
ZTest Always
ZWrite On
Color$$anonymous$$ask 0
Pass
{
CGPROGRA$$anonymous$$
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
float _fovSize;
struct appdata
{
float4 vertex : POSITION;
};
struct v2f
{
float4 vertex : SV_POSITION;
float4 posInObjectCoords : TEXCOORD0;
};
v2f vert(appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.posInObjectCoords = v.vertex;
return o;
}
struct fragmentOutput
{
float zvalue : SV_Depth;
fixed4 color : SV_Target;
};
fragmentOutput frag(v2f i)
{
fragmentOutput o;
o.zvalue = 0.0;
o.color = (1, 1, 1, 1);
_fovSize = 0.1;
if ((i.posInObjectCoords.y <(-_fovSize) || i.posInObjectCoords.y >(_fovSize)) ||
(i.posInObjectCoords.x <(-_fovSize) || i.posInObjectCoords.x >(_fovSize)))
{
o.zvalue = 1.0;
}
return o;
}
ENDCG
}
}
}
I'm really novice with shader and i read pages you have suggested.
