Can someone please tell me how to select the inner quads and delete them, basically I'm learning to implement A* and want to create a navmesh that will later be used in unity.

Here's the image.

It could depend also on the resulting mesh you wish to obtain, eg:

• a big plane with only 4 vertices?

• a big empty plane with only 4 vertices?

• the plane as it is but without inner quads?

see a couple of example below, using dissolve commands

with dissolve vertices, but you get a plane of more than 4 verts

or with dissolve edges

...you get the idea...

 in the tutoarial you are following inthe link above, it says

"Create a plane, subdivide it two times and then remove the inner four quads."

well,

• first, it is wrong: to get the subdivided plane I see in that image, which has a total of 16 face after subdivision, you have to subdivide the plane 3 times, not 2.

then it seems to convert those inner 4 faces into a a big square.

so you can switch to select faces mode, selet the inner 4 faces, and simply "dissolve faces"... like this

• How do I select specific quads? Commented Nov 20, 2015 at 9:28
• As shown above, select vertices or edges. But you can also do this: select all quads, switch to select edges and press CTRL-X Commented Nov 20, 2015 at 9:41
• Nope, I don't think i'll be able to do it Commented Nov 20, 2015 at 10:01
• It says, subdivide the plane two times and then remove inner four quads. And I don't even know how to select and remove! Commented Nov 20, 2015 at 10:01
• "it says"... Are you meaning in the the link you put in the post? I'll check it out. If you try on a simple quad subdivided, my method works, but in that tutorial, something could be different, let me check it. OK. I'll edit my answer. Commented Nov 20, 2015 at 10:04

Making the shape pictured below (a plane with a hole in it) is very easy.

All you have to do is select the center vertex and delete it, with Delete > Vertices (or X > Vertices ).