Ok, this version worked!
There was still an error-message when I opened it in the editor but it loaded.
Here is the message:
First of all: I don't know how it's going to play later one when it's finished, but this is one nice looking map already!
Based on you not knowing how to use the myLevel package I expected something that looked much more like a newbie's work, but this looks really good!
Now on to optimization. Some of these tips won't help reducing the size of your map (e.g. the substitutions for some textures which are in retail-packages won't help reducing the size of your map-file as they are stored in packages everyone has already, but the substitutions will help to reduce the strain on people's graphicscards as they will use less memory). Ok, here we go:
You have some textures in your myLevel package which are abnormally large!
There is a 4096*4096 (!) bunker texture. That's pretty much insane. The engine can handle it, and most graphics cards can handle it too, but do they have to?
You can export the texture and scale it down to 1024*1024 and it won't look noticably worse in-game but it'll only be a 16th of the size of the 4096² monster! Maybe it won't "fit" the StaticMesh when you try to apply it to it
. If this is the case create a texture scaler (in the texture browser File -> New), use the newly imported bunker texture as its material and scale it. Use the texture scaler as the StaticMesh's skin then.
A Fritz skin is in there which is 2048*2048. I don't know how large the regular RO skins are but either way, that's too large. Again, 1024*1024 will look just as good. No one will be able to see a difference but the texture's size will be quartered!
Basically, try and keep your textures to 1024*1024 or below.
Almost all your lightmap resolution seem to be set to default (32). You can reduce that on many surfaces. Here is an example:
The surface is in the shadow of the building and unless you put more lights there (maybe from a lamp or something) the whole surface can basically be lit the same! There would technically be no need for a lightmap bigger than 1*1 on that surface! On surfaces like this you can drastically reduce th lightmap-resolution. Set it to 256 in this example and go through your map searching for more of these cases.
The terrain resolution is WAY too high! 256*256 would work just as well! I know it's a huge terrain, but if you look at the individual sectors you will see the resolution is too high. Just as a rule-of-thumb: A sector of the terrain should be at least as big as a tank! If the terrain is mostly flat it can be even bigger without it looking much worse! A reduction to 256*256 from 1024*1024 means the reduction of the size to a 16th! This applies for the deco-layers as well!
Export your heightmap and use photoshop or something similar to reduce the size to 256*256 and then import it again (with a different name, for now). You will have to do the same with different formats for the deco-layers or you can delete them and make them again by hand. Delete the texture and deco layers from your terrain (they have to have the same size as the heightmap and that's going to change now). Open the TerrainInfo Properties and use the newly imported heightmap as its Terrainmap. Use the TerrainScale below to adjust the scaling so the new Terrain has the same size as the old one. If you only changed the size of the heightmap to a quarter of a side's length (1024 -> 256) then you should be able to make it fit by scaling it with the factor *4 on both the x and the y axis.
You will need this program
. Use the documentation of that site to find out what it does and why.
You can use another terrain for detail work like your trenches or you can make these differently. E.g. with StaticMeshes or with BSP. There are examples of all of these methods in RO maps.
ColorModifiers instead of different textures!
These two textures wheat_big_yellow and wheat_big_yellow_light are identical except one is brighter than the other! You can easily get rid of one of them and use a colormodifier instead. Create a colormodifier (texture browser -> File -> New) and use one of them as its material and adjust its color. Use the colormodifier instead of the other texture then. You also have loads of different wooden plank textures which are more or less the same except for their color! You can use one of them (preferably one with a more neutral, greyish color) and create some color-modifiers and use those instead of the many other wooden plank textures. The same is true for your different sand-bag textures, your concrete and plaster textures, some of your dirt textures and maybe more.
You can also color the projected craters that way and make them look a bit different depending on where they hit. E.g. darker where they hit mud and lighter where they hit sand. Or you can color some of your leaves (either to replace others that are similar except for the color or) to create even more variation. E.g. some that are already a little brown, some that are still greener, etc.
Don't overdo it (e.g. you can keep a concrete wall plus a damaged concrete wall. Stuff that really does look different on a structural level) but you can seriously cut down on the memory waste by using colormodifiers instead.
On a similar note: re-use more of the debris / litter! You have different debris at every corner. Some of it is only used once. If you would reuse more of it instead of using new stuff everywhere this would help as well. Again, don't overdo it. Diversity is nice. But keep it in mind.
Use Culldistances for small deco stuff!
This thing here doesn't have to be seen too far. The culldistance value means it can only be seen if the player is as close or closer to it than the specified value in unreal units. Many of the smaller debris pieces that can't be used for cover anyway can have a relatively low culldistance. Some other examples where this can be handy are window frames or the two dead Russians near the broken truck.
One last thing for now: Zone off your houses where applicable. With many windows and doors I suspect it won't help a whole lot but it's worth a try for some.
The changes with the terrain are the messiest and the most work but they will help the most, both in regards to map-size and performance.