如何添加树的季节性变化？

问题

• 我想通过Terrain绘制工具给树木添加季节性变化。但树在Hierarchy面板不并不是以GameObject的形式存在。 

原因

没有换树木Prefab的功能。

解决方案

Unity Terrain用数组Terrain.treeInstances暴露树的实例。数组的每一个树的实例在Terrain设置(prototypeIndex)中都有一个属性存储树prefab的配置。

树prefab 通过改变这个值自动更新。

TreeInstance[] currentTreeList;
TerrainData terrain;
int springTreeIndex;
int fallTreeIndex;
bool season;

void ChangeSeasons ()
{
    // The currentTreeList array must be at least

terrain.treeInstances.Length in size

//currentTreeList数组的大小至少为terrain.treeInstance.Length
    System.Array.Copy (terrain.treeInstances, currentTreeList, terrain.treeInstances.Length);
    if (terrain.treeInstances.Length == currentTreeList.Length)
    {
        for (int tcnt=0; tcnt < currentTreeList.Length; tcnt++)
        {
            if (season)
            {
                if (currentTreeList [tcnt].prototypeIndex == springTreeIndex)
                    currentTreeList [tcnt].prototypeIndex = fallTreeIndex;
                }
                else
                {
                if (currentTreeList [tcnt].prototypeIndex == fallTreeIndex)
                    currentTreeList [tcnt].prototypeIndex = springTreeIndex;
            }
        }
        terrain.treeInstances = currentTreeList;
        season = !season;
    }
}

更多信息

http://answers.unity3d.com/questions/521056/access-terrain-tree-material-from-script.html