how do i add a line on this model

[cobra_violet]

this picture shows a cylinder like structure im working on for a project. in the picture is the highlighted face that i want to apply lines to. the red lines are the results i want. how do i achieve this? should i extrude one corner then merge at the other side?

[Richard_Marklew]

Select the top and bottom middle vertices and press J to connect the them. Then use K (knife tool) to cut between the two side vertices and cut the edge you just made.

Make the vertical cut first so you maintain the circular cross section.

Demo: http://screencast.com/t/b5yYyqDFNXu

[Sanctuary]

Select the top and bottom middle vertices and press J to connect the them. Then use K (knife tool) to cut between the two side vertices and cut the edge you just made.

Make the vertical cut first so you maintain the circular cross section.

Demo: http://screencast.com/t/b5yYyqDFNXu

To add on this, in the incoming Blender 2.68 (and so in current buildbot versions) , the J to connect vertices got an upgrade and is now able to connect vertices by crossing through several edges, creating the required cuts all by itself.
So in 2.68 you will only need to use J, you will not need the knife to cut the edge after that, the J upgrade will do that automatically

[sabba]

That’s a nice improvement, Sanctuary! Thanks for the tip.

[JA12]

There’s also another cool tool coming in 2.68 called grid fill. Not that fast with the face shown in the starting post but if you have a larger area to fill: select the face, delete it, select two edge loops, grid fill.