Using the demo level Sunset Island, and using the F1 light map action, the program took about two and a half minutes to build the lightmap. Is this the normal level of performance? Also, after having built the lightmap, shadows on rock entities notably shimmered when the player moved.

Lightmapping times will vary depending on scene complexity and PC how fast your PC is.

Pre-baked lighting is still a work in progress so there are several issues with it currently.

@Polaraul

The Shimmering is a bug ... This has been reported and rectified for 0.28 ..
If you lightmap a fresh map it should be fine ..... If you light map a second time you get the shimmering .... hence your error with sunset island as its already been done once ...

But all is good for the update

I have a monster computer. Light mapping is still slow. Needs a lot of work.

Thank you for all the replies.

I didn't even attempt anything more complex than the F1 light map as it was just too slow in the production process. I have been out of touch with GG for a while, but looking at what is being planned, I really hope that this type of core functionality gets some priority over new features. I think I read somewhere that GG only uses one core, perhaps this is the issue.

Lightmapping is an intensive process and I can't see it speeding up much really. It already uses multiple cores, indeed it is the only part of Game guru that does at this point. It has been suggested by myself and others to have some way of making the bake process run while you are in the editor, so it does each part as you place items down, so would be a better option. That way although it may slow things in editor a tad (after placing an item it would be baked) it would avoid the sitting waiting process that is currently available.

I have had to wait over 5 hours on some maps with an F3 bake. It can be a slow process when you have a large and complex map.

Glad to see people using my map!

You should try a production quality light bake on a complex scene in Unreal Engine 4... just have a copy of War And Peace handy, oh, and a good 32Gb of RAM in your machine...

Incidentally, any good quality lighting algorithm, be it static, baked or dynamic is always going to be very intensive...
For an idea of whats involved, here's a great video of The Carmack explaining the techniques:

Be aware of Models with things like Scale = 5000 in the FPE
It will take the whole grid to lightmap this one object and about 20 minutes ...but a t should take 30 seconds
so if you have 10 of these scaled models in your map then lightmapping can take hours ...

Just a bit of info