1. Navigational Mesh
2. Place Painting

Now we have an effective nav mesh, we still have one more step to go. You'll notice in the official CS:S maps that the green radar indicates your position and your teammates's position during radio communication. This makes team work possible, and this is made possible by place painting.

Place painting is basically inserting additional information to the existing navigational mesh. The information is also saved in the .NAV file. It's done with a different set of commands, similar to nav editing.

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