why are shadows in UED Better BEFORE rebuilding?

[alto]

When you have an object that casts shadows in UED4, before you rebuilds it "guesses" where the shadows are gonna be, and it casts perfect shadows on other objects, but when you rebuild you get, simply put, strange shadows that are WAY to soft and the static meshes that the shadow is cast onto just goes completely black sometimes.

I know about the texture properties thing where you can change the resolution or something to make shadows finer (I can't remember what It's called) but is there an option like this for static meshes? I always hated how Unreal Engine handles static meshes, some things are great, collision is great, but lighting is a really bad point. Unless I'm missing something, do you really have to use lightmaps? (pre-made ones... I can't think what they are atm)

I'm probably making no sense because I bumped my head and its screwing my mind up so yeah...

[MrSilent]

I know exactly what you mean, Im leaving my lighting for now and concentrating on other things because ive already lost soo much time testing etc.
Its gotta be a flag somewhere, just don't know which one, would love to hear some suggestions also.

[ts_falcon]

by default all static meshes are vertex lit. so unless you have either a dense mesh or one that was designed to be vertex lit, it probably wont look too good.however, with the new version of unreal you can lightmap SM's just like the bsp. to do this you need to add another uv channel to the mesh and this is explained here (http://www.hourences.com/book/tutorialsue3lightmap.htm)

this is "expensive" however so you wouldnt want to do it on all your static meshes. if you look through the gears maps, most of the props are still vertex lit, with only the larger ones having their own lightmaps. if you are looking for razor sharp shadowing, you need to use a dynamic light, which can really bog down performance if you have a bunch of them. plus, shadows in real life dont tend to have those super sharp edges and by using lightmaps effectively you can get some really nice soft shadows.

[Ganjaman]

I wanted to ask the same question but then i saw your post, i have the same problem.

When i placed lights or a static mesh (or even moved these) the shadows look sharp but after a rebuild the shadows are like we are all used to in the old ued editor.

Not sure whats the deal but when i load in a gow map i dont see sharp shadows aswell (only after moving some lights)

Btw: i have less problems with the light on a static mesh with this engine , i use to set shadows to off on the static meshes in the old ued so i would not have weird dark shadows on my mesh.

[CrysAk]

adding lights in unreal without building shows them as DYNAMIC, with sharp real time (expensive)shadows

rebuilding the level renders "lightmaps" which is a much cheaper way to view lights/shadows in game at the expense of not so sharp shadows

you can alter the lightmap resolution to be higher and therefor being sharp again but this again comes at a performance cost