.Map :: MoHAA Mapping

how do you circles like for train wheells?

You have choices for this.
You can (not recommended) create a cylinder, and cap it. (In Radiant, click Curve-->Primitives-->cylinder. Then choose Curve-->cap-->inverted endcap)

Or (recommended) Create a brush the approximate size you want the wheel. Then go to Brush-->Arbitrary sided, and then type 12.
I find a 12 sided brush works very well for round objects, and saves face count (and therefore performance) over a cylinder.

Of course, you may have to resize and rotate the brush, since the brush-->Arbitrary sided is going to make your sides along the z-axis (visible as "round" in xytop view).
Just be sure to set your grid to "1" and then ctrl + g to "snap" the brush back to the grid.

Hope this helps. Kill Ya Later!

another way could be making a custom texture of a wheel front with the space around the wheel and between the spokes being transparent.

This way u would get a perfect round wheel (which could even be rotating with an appropriate shader) with a brush of just 6 sides (5 with nodraw). The bad thing is that it won't be 3-dimensional.

Depends on how u would use it...