Unity3d 使用 Node Canvas

Node Canvas

Node Canvas是一个行为树的插件，它是图形化的操作模式，可以简化开发逻辑，官方文档在这 .

基本元素

流程上的原则是，一旦返回值为False则向上返回。一般在BehaviourTreeOwner组件上，要勾选Repeat循环监测。通常这些监测指的是各子树的条件判断。常用的元素如下：

元素名称	对应逻辑	备注
Action	操作	各种操作，用过都说好
Condition	条件判断	各种判断，没它真不成
Selector	选择器	逻辑|| 如果有返回为真的子树，则停止执行，返回真
Sequencer	顺序器	逻辑&&与Selector相反，有返回假的，则返回假
Parallel	并行器	“同时”执行子树，返回值根据Policy取舍
Conditional	条件节点	如果不合条件，直接返回False，不执行子节点
Filter	过滤器	限制性访问，比如初始化时只进一次
Iterate	迭代器	做循环用
OverrideAgent	复写变量	对于子节点，不使用行为树挂载的Agent

快捷键

Here are the node/canvas controls and shortcuts:

• Right Click on the canvas to add a new node.
• Click & Drag to pan the node.
• Middle Click & Drag in the canvas to pan the canvas.
• Shift + Click & Drag a node to pan it and all of it’s children together; panning a branch.
• Click & Drag from a port over a target node to connect. Right click a connected port to disconnect.
• Click & Drag from a port into empty canvas space, will show context menu to automaticaly create and connect a new node.
• Click a connected port or connection itself to select the connection.
• Delete the selected node or connection with Delete Key, or through the right click context menu.
• Duplicate a node with Control+D or through the right click context menu.
• Double Clicking a node will open it’s script in the IDE, unless it’s a Nested Node in which case it will open the nested tree.
• Relink a connection by click and dragging it over a new node.
• Hit “F” will focus the canvas on the center of all your nodes within it.
• Mouse Scroll Wheel will Zoom In/Out the canvas.
• Left Click and Drag in the canvas, will allow you to create a selection rectangle.
• Holding Control while making a rectangle selection will create a Canvas Group.

On right click on a node or connection, a context menu will show up. Depending on the node or connection type there might be different extra options. Following are the common operations:

• Delete: Deletes the Node or Connection. (available in multiselection as well).
• Copy Node: Copies the Node possible to Paste later. (available in multiselection as well)
• Copy Assigned Task: Will copy the task that has been assigned to the Node or Connection.
• Paste Assigned Task: Will paste the currently copied Task to the Node or Connection and assign it.