Brush has null material referances??? PLEASE HELP

[LtClifff]

Hi guys. I have started work on a stalker esq map (trying to recreate rookie camp) and it was all going well. Then one time I build the map and suddenly I cannot see half of the walls. I check map for errors and it says brush has null material referances What does this mean? And how do you fix it?

Please help me... I do not want to start again...

[D-Hunter]

You need to apply a material to the surface. Select a surface, then open up the Generic browser and select a material and it will automatically be applied.

[Nawrot]

to get rid of that annoying warning, select any CSG surface, right click then pick select all surfaces and apply some material. this will pain your whole level with same texture. And will help for some time.

Engine likes to optimise invisible surfaces by removing their materials, but later when you for eg move your brush surface with empty material will reapearr and engine will complain.

So for most time ignore those warnings and care only about visible surfaces. Then from time to time run "clean CSG surfaces" tool.

Also there is one good habbit I want to recommend:
at beginning of every day save your map under name with incrementing version number. Sometimes engine corrupts map, or you want go back to older version when you mess something. Or you had great idea before but it did not fit well in room, and you think it is awesome for new one spot. And so on.

For eg. I found out how to modify material from kismet and i liked resulting effect, but then i decided its too flickering for big floor surface, so i removed it. After 2 weeks I wanted to implement same effect for small detail surface where flickering does not annoy. I had to redo all effect if i did not made backup copy of old map.

Also get used to habit pressing "save" right before build all. Autosaves sometimes do strane things and like to start when i am moveing half of level.