Building and rebuilding fast No building room Now, you got several brushes, adds and substracts mixed. You dun like making a builder room, and want your multiple brush fast >>>> You made your elemental brushes for this complex brush, transport them out the map to an unused location. Reverse all CGS of the brush, meaning, substracts > adds, all adds > substracts. Cos you are in solid space only substracts are made, the adds will be left out > obvious So you have finaly left all substracts who were adds before in the map. Now make the red builder brush big enough to enclose all brushes. now logicaly, De-Intersect. You can now see that only the substracts are taken by the red builder brush. Take the red builder brush to the place were you wanna make it. Now press add again, you got your complete additif brush. What happened and why is this >>> In solid space only substracts are possible so all the brushes that have to remain should be substracts. in map only adds are used, so we will reverse this to be able to make it in solid space. Once done, you can see and work on the substract in inversed view. When all is done, and you merged the polygons, you can import the red builder as additif brush in map again. Anyone knows that rebuilding is very important. Very anoying thing is that it can take up lot of time. No worries, here bull touch >> Make and work with groups. make a group of all that should belong togheter. uncheck all unused groups, leave only the group you need to work on right now. Open settings for complete rebuild. Between Geometry and BSP, check the small square named Only rebuild visible actors. Now when you rebuild, only the visible brushes will be rebuild at lightspeed. do this untill all your work is done in this group. Do the same for all groups where you need to work on. Now, what's the point to this ? >>>> if you make your complex brushes like i explained in part one, you will use only the group where this brush has to be build in. making rebuild very fast, you can rebuild untill you got your complete brush and well in place.