I just threw together a couple target ring images. I was hoping that the con ring would be a separate, stationary texture so I could put a pointer on one side so you could more easily see the direction a mob is facing but it looks like it rotates with the target ring.
One strange thing I noticed is that at certain camera distances the con ring sends out a colored line that circles like a beacon. This might be because the two DDS tools that I use (the GIMP plugin and the Microsoft DirectX Texture Tool) make 10 mip maps whereas the default target rings only use 3. What would be the easiest way to to generate just 3 mip maps (without the NVIDIA Photoshop plugin)?
Hmm, after some more research it looks like the ATI Compressonator can make a specific number of mip maps. Othewise it's kind of a clunky program.