Shader Graph

using UnityEngine;
using System.Collections;

public class DissolveEffect : MonoBehaviour
{
  // Property name must match the Shader Graph blackboard
  static readonly int DissolveID = Shader.PropertyToID("_DissolveThreshold");

  Renderer rend;

  void Awake() => rend = GetComponent<Renderer>();

  public void PlayDissolveOut(float duration = 1f)
  {
      StartCoroutine(DissolveRoutine(0f, 1f, duration));
  }

  public void PlayDissolveIn(float duration = 1f)
  {
      StartCoroutine(DissolveRoutine(1f, 0f, duration));
  }

  IEnumerator DissolveRoutine(float from, float to, float dur)
  {
      float t = 0f;
      while (t < dur)
      {
          t += Time.deltaTime;
          rend.material.SetFloat(DissolveID, Mathf.Lerp(from, to, t / dur));
          yield return null;
      }
      rend.material.SetFloat(DissolveID, to);
  }
}

// HLSL fragment shader equivalent of the graph above
// (ShaderLab wrapper omitted for brevity)

// Properties matching the Shader Graph blackboard
float4 _BaseColor;
sampler2D _BaseMap;
float _DissolveThreshold;   // Driven from C#
sampler2D _NoiseMap;

float4 frag(v2f i) : SV_Target
{
  // Sample noise at the mesh UV
  float noise = tex2D(_NoiseMap, i.uv).r;

  // Step: clip the pixel if noise < threshold
  float dissolve = step(_DissolveThreshold, noise);
  clip(dissolve - 0.001f);  // Discard if dissolve < 0.001

  // Edge glow: pixels near the boundary light up
  float edgeWidth = 0.05f;
  float edge = step(_DissolveThreshold - edgeWidth, noise) * dissolve;
  float3 edgeColor = float3(1, 0.4, 0.1) * edge * 3f;

  float4 baseColor = tex2D(_BaseMap, i.uv) * _BaseColor;
  return float4(baseColor.rgb + edgeColor, baseColor.a);
}