MicroSplatBoundsHole.cs

using Sirenix.OdinInspector;
using System.Collections.Generic;
using Unity.Mathematics;
using UnityEngine;

namespace AiGame.Terrains
{
    public class MicroSplatBoundsHole : MonoBehaviour
    {
        private const int MaxHoles = 50;

        [SerializeField]
        private MicroSplatTerrain MicroSplatTerrain;
        [SerializeField]
        private BoxCollider Collider;
        [SerializeField]
        private List<float3x2> Holes = new List<float3x2>();
      
        private void Start()
        {
            MicroSplatTerrain.OnMaterialSync += OnMaterialSync;
            MicroSplatTerrain.Sync();
        }

       
        private void OnMaterialSync(Material m)
        {
            MicroSplatTerrain.OnMaterialSync -= OnMaterialSync;

            Vector4[] shaderArray = new Vector4[MaxHoles * 2];
            int index = 0;
            for (int i=0;i<Holes.Count;i++)
            {
                float3x2 hole = Holes[i];
                shaderArray[index] = new Vector4(hole.c0.x, hole.c0.y, hole.c0.z);
                index++;
                shaderArray[index] = new Vector4(hole.c1.x, hole.c1.y, hole.c1.z);
                index++;
            }

            m.SetVectorArray("_BoundsHoleArray", shaderArray);
            m.SetInt("_BoundsHoleCount", Holes.Count);
            
        }

        [Button("SetHole")]
        public void SetHole()
        {
            SetHole(Collider.bounds);
        }

        public void SetHole(Bounds bounds)
        {
            if (Holes.Count > MaxHoles)
            {
                throw new UnityException("MaxHoles exceeded");
            }

            Holes.Add(new float3x2(bounds.min, bounds.max));

            MicroSplatTerrain.OnMaterialSync += OnMaterialSync;
            MicroSplatTerrain.Sync();
        }

        [Button("ClearHoles")]
        public void ClearHoles()
        {
            Holes.Clear();

            MicroSplatTerrain.OnMaterialSync += OnMaterialSync;
            MicroSplatTerrain.Sync();
        }
       
    }
}

// shader content


	// Surface function should call ClipAllBounds with i.worldPos


	// property
	_BoundsHoleCount("BoundsHoleCount", Int) = 0

	// shared
	float4 _BoundsHoleArray[100];
	int _BoundsHoleCount;

	 
	void ClipBounds(float3 min, float3 max, float3 pos) {
		float a = step(min.x, pos.x);
		float b = step(pos.x, max.x);

		float c = step(min.y, pos.y);
		float d = step(pos.y, max.y);

		float e = step(min.z, pos.z);
		float f = step(pos.z, max.z);

		clip(5.0f - a - b - c - d - e - f);
	}

		
	void ClipAllBounds(float3 worldPos)
	{
		int index = 0;
		for(int i=0;i<_BoundsHoleCount;i++)
		{
			float4 min = _BoundsHoleArray[index];
			index++;

			if (min.x > 0.0f)
			{
				float4 max = _BoundsHoleArray[index];
				ClipBounds(min.xyz, max.xyz, worldPos);
			}
			
			index++;
		}
	}