How to animate disappearing Object?

Questions & Answers
1

I want a GameObject like the cube do fade in or fade out when I want it to.
With fading in and out I mean that the Object seems to disappear and slowly becomes invisible.

I know that if I want to make an Object invisible I can do gameObject.SetActive(false). But I want it to be animated.
I also tried changing the Renderers alph over time. That works but doesn´t look good. And even if the object is fully transparent you can still see it.

So I thought about creating a transparent wall that somehow hides the Object. So that you don´t see the wall and you don´t see the gameObject. I don´t know if this is even possible.

Does anyone have a better aproach about doing this? Or do you have any idea on how I would realize my idea?
Thanks in advance!

3

you need shaders for this.

Shader "Custom/Fade" {
	Properties
    {
        _Color ("Color", Color) = (1,1,1,1)
        _MainTex ("Albedo (RGB)", 2D) = "white" {}
        _Glossiness ("Smoothness", Range(0,1)) = 0.5
        _Metallic ("Metallic", Range(0,1)) = 0.0
        _Visibility ("Visibility", Range(0,1)) = 1
    }
    SubShader
    {
        Tags {"Queue" = "Transparent" "RenderType"="Transparent" }
        LOD 200
   
        CGPROGRAM
 
        #pragma surface surf Standard fullforwardshadows alpha:fade
        #pragma target 3.0
 
        sampler2D _MainTex;
        float _Visibility;
 
        struct Input {
            float2 uv_MainTex;
        };
 
        half _Glossiness;
        half _Metallic;
        fixed4 _Color;
 
        void surf (Input IN, inout SurfaceOutputStandard o)
        {
            fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
            o.Albedo = c.rgb;
            o.Metallic = _Metallic;
            o.Smoothness = _Glossiness;
            o.Alpha = _Visibility;
        }
        ENDCG
    }
    FallBack "Standard"
}

This is a basic Standard Surface Shader. I modified a bit so you can change the visibitily.
All you need to do is make a script that changes the _Visibility value.

bool FadeIn() {
	float val = Mathf.Lerp (0, 1, t);
	t += speed * Time.deltaTime;
	renderer.material.SetFloat ("_Visibility", val);
	return t > 1;
}

If the Fade is done the method returns true. After every fade you need to reset the variable t to 0.
Good Luck!

2

You need to create your own shader if ou want it to be perfect. Plugins like Amplify Shader and Shader Forge can help you create it.

4

If you have SpriteRenderer, you can create animation where you change alfa value of color from 1 to 0 over time.