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 :slight_smile:

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.