Does Lightmap resolution affect performance much?

Hello, after playing with the LightmapWizard on Unify, (here) I'd like to increase my Lightmap resolution to get a little more detail on the tree shadows. Doing a quick test swapping between 512,1024 & 2048, I can't see a frame rate difference but the shadows look better.

Can I assume that it's safe to do this if I'm not seeing an obvious performance hit, or might there be hidden problems lurking?

Thanks

Steve

It really depends on the size of the map and what type of game you're making. If it's an FPS go for 2048 otherwise the shadows will look funny. There is a performance hit but if you want decent looking terrain it's a good trade off.

Here's some stuff about light maps:

http://www.unifycommunity.com/wiki/index.php?title=Terrain_tutorial#Prepare_the_lightmaps