U3D运行时修改地型中的树木_treeinstance 碰撞

Vector3.Scale(currentTree.position, terrain.size) + Terrain.activeTerrain.transform.position;

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using System;
 
 
public class TreeChop : MonoBehaviour
{
	public GameObject FallingTreePrefab;
	private List<TreeInstance> TreeInstances;
	// Use this for initialization
	private void Start()
	{
		TreeInstances = new List<TreeInstance>(Terrain.activeTerrain.terrainData.treeInstances);
		Debug.Log("Tree Instances:" + TreeInstances.Count);
	}
	
	// Update is called once per frame
	private void Update()
	{
		// did we click on a tree?
		if (Input.GetMouseButtonDown(0))
		{
			DateTime start = DateTime.Now;
			RaycastHit hit;
			// This ray will see where we clicked er chopped
			Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
			
			// Did we hit anything at that point, out as far as 10 units?
			if (Physics.Raycast(ray, out hit, 10.0f))
			{
				// Did we even click er chop on the terrain/tree?
				if (hit.collider.name != Terrain.activeTerrain.name)
				{
					// No, must have been a frantic attack on a giant spider >:)
					return;
				}
				
				// We hit the "terrain"! Now, how high is the ground at that point?
				float sampleHeight = Terrain.activeTerrain.SampleHeight(hit.point);
				
				// If the height of the exact point we clicked/chopped at or below ground level, all we did
				// was chop dirt.
				if (hit.point.y <= sampleHeight + 0.01f)
				{
					return;
				}
				
				TerrainData terrain = Terrain.activeTerrain.terrainData;
				TreeInstance[] treeInstances = terrain.treeInstances;
				
				// Our current closest tree initializes to far away
				float maxDistance = float.MaxValue;
				// Track our closest tree's position
				Vector3 closestTreePosition = new Vector3();
				// Let's find the closest tree to the place we chopped and hit something
				int closestTreeIndex = 0;
				for (int i = 0; i < treeInstances.Length; i++)
				{
					TreeInstance currentTree = treeInstances[i];
					// The the actual world position of the current tree we are checking
					Vector3 currentTreeWorldPosition = Vector3.Scale(currentTree.position, terrain.size) + Terrain.activeTerrain.transform.position;
					
					// Find the distance between the current tree and whatever we hit when chopping
					float distance = Vector3.Distance(currentTreeWorldPosition, hit.point);
					
					// Is this tree even closer?
					if (distance < maxDistance)
					{
						maxDistance = distance;
						closestTreeIndex = i;
						closestTreePosition = currentTreeWorldPosition;
					}
				}
 
 
				// replace the tree prototypeIndex
				var temptree = new TreeInstance();
				temptree.prototypeIndex = 6;
				temptree.position = treeInstances[closestTreeIndex].position;
				temptree.color = new Color(1,1,1,1);
				temptree.lightmapColor = new Color(1,1,1,1);//must add
				TreeInstances.Add(temptree);
 
				// Remove the tree from the terrain tree list
				TreeInstances.RemoveAt(closestTreeIndex);
 
				//set back treeInstances array
				terrain.treeInstances = TreeInstances.ToArray();
 
 
				
				// Now refresh the terrain, getting rid of the darn collider
				float[,] heights = terrain.GetHeights(0, 0, 0, 0);
				terrain.SetHeights(0, 0, heights);
 
		 //		Terrain.activeTerrain.collider.enabled = false;
		 //		Terrain.activeTerrain.collider.enabled = true;
 
		 //		Terrain.activeTerrain.Flush();
				// Put a falling tree in its place
				Instantiate(FallingTreePrefab, closestTreePosition, Quaternion.identity);
				Debug.Log(DateTime.Now - start);
			}
		}
	}
}

temptree.color = new Color(1,1,1,1);
temptree.lightmapColor = new Color(1,1,1,1);

			// Now refresh the terrain, getting rid of the darn collider
				float[,] heights = terrain.GetHeights(0, 0, 0, 0);
				terrain.SetHeights(0, 0, heights);
 
		 //		Terrain.activeTerrain.collider.enabled = false;
		 //		Terrain.activeTerrain.collider.enabled = true;
 
		 //		Terrain.activeTerrain.Flush();