Routing - Auto Completion

Interactively Routing a Net - English documentation - The Altium Wiki: 

"The Interactive Router is able to attempt automatic completion (Auto-Complete) of connections to the target pad, hold CTRL and Left Click to instruct the Interactive Router to attempt to complete the current connection. 

This can make routing much faster than placing individual track segments, however, there are some limitations to Auto-Complete feature, as follows: 

Start point and target pad are on the same layer The route can be completed in accordance with design rules (provided that routing conflicts are not being ignored). 

Auto-Complete is available at any time, and you can even CTRL + Click directly on a pad or connection line to route it, there is no need to select it first. 

You can use Auto-Complete on connections that are partially routed as well. To do this, CTRL + Click on the end of the last track segment or the remaining connection line to complete it to the target. 

 If a connection cannot be auto-completed the tool will return to the last used interactive routing mode."

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