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Changinge the value of a shader over time
Hi. I am trying to change shader vaules over time on a object.
I Found shader HSV_shader, which enables me to change HueShift, Value and Saturation on texture. But I have no idea how to change those values over time. Can someone please hlep me.
The shader:
Shader "Custom/HSVShader" {
Properties {
_MainTex ("Texture", 2D) = "white" {}
_HueShift("HueShift", Float ) = 0
_Sat("Saturation", Float) = 1
_Val("Value", Float) = 1
}
SubShader {
Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType" = "Transparent" }
ZWrite Off
Blend SrcAlpha OneMinusSrcAlpha
Cull Off
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma target 2.0
#include "UnityCG.cginc"
float3 shift_col(float3 RGB, float3 shift)
{
float3 RESULT = float3(RGB);
float VSU = shift.z*shift.y*cos(shift.x*3.14159265/180);
float VSW = shift.z*shift.y*sin(shift.x*3.14159265/180);
RESULT.x = (.299*shift.z+.701*VSU+.168*VSW)*RGB.x
+ (.587*shift.z-.587*VSU+.330*VSW)*RGB.y
+ (.114*shift.z-.114*VSU-.497*VSW)*RGB.z;
RESULT.y = (.299*shift.z-.299*VSU-.328*VSW)*RGB.x
+ (.587*shift.z+.413*VSU+.035*VSW)*RGB.y
+ (.114*shift.z-.114*VSU+.292*VSW)*RGB.z;
RESULT.z = (.299*shift.z-.3*VSU+1.25*VSW)*RGB.x
+ (.587*shift.z-.588*VSU-1.05*VSW)*RGB.y
+ (.114*shift.z+.886*VSU-.203*VSW)*RGB.z;
return (RESULT);
}
struct v2f {
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
};
float4 _MainTex_ST;
v2f vert (appdata_base v)
{
v2f o;
o.pos = mul (UNITY_MATRIX_MVP, v.vertex);
o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
return o;
}
sampler2D _MainTex;
float _HueShift;
float _Sat;
float _Val;
half4 frag(v2f i) : COLOR
{
half4 col = tex2D(_MainTex, i.uv);
float3 shift = float3(_HueShift, _Sat, _Val);
return half4( half3(shift_col(col, shift)), col.a);
}
ENDCG
}
}
Fallback "Particles/Alpha Blended"
}
I also did the script in which I am trying to call and change those values.
using UnityEngine;
using System.Collections;
public class HsValue : MonoBehaviour {
void Start() {
renderer.material.shader = Shader.Find("HSVshader");
}
void Update() {
float _Sat = Mathf.PingPong(Time.time, 0.0F);
renderer.material.SetFloat("Saturation", _Sat);
float _HueShift = Mathf.PingPong(Time.time, 1.0F);
renderer.material.SetFloat("HueShift", _HueShift);
float _Val = Mathf.PingPong(Time.time, 1.0F);
renderer.material.SetFloat("Value", _Val);
}
}
Thanks for help :)
Tbh I can't see a reason for your hue and value to not be working but I thought I'd point out a few $$anonymous$$or problems. Firstly, saturation will currently always be 0 as you have set the length of the pingpong to 0. Secondly, it is bad practice to be creating 'new variables' every frame which is what happens when you have float _Sat etc, it is preferable to create the variable outside of the function and simply change their values in update (like Evil Tak suggested). Finally (and not really a problem) but in general, na$$anonymous$$g convention means that names like '_Val' are the ones inside your shader and 'Value' would be the name of your float variable but that is just convention, and it appears you are still using the right variable in the right place assu$$anonymous$$g the variable names in your shader are Saturation, HueShift and Value!
Oh just realised, you are not calling the SetFloat method correctly as I sort of mentioned in point 3 of my last comment. I think it should be:
renderer.material.SetFloat("_Sat", _Sat);
as _Sat is the name of the variable in your shader, similarly for the other 2!
Answer by EvilTak · Oct 08, 2014 at 10:00 AM
You can use something like this:
public float speed;
float sat, hueShift, val;
void Update(){
float t += Time.deltaTime * speed;
t = Mathf.Clamp01(t);
sat = hueShift = val = t; //If you want the value to be same
}
If you want the value of hueShift, sat and val to remain same. If not, you could use different values for both, you can use different speed variables for each of them.
Your answer
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