Regarding what I do to obscure rooms in the NWN toolset, whenever possible I keep the next room scrolled off of the screen so it is not seen.
This is not always practical, however.
My general approach when there will be a lot of interior exploring is to use simply an image(s) of the map and prepare a map using Tabletop Mapper. For a number of reasons, building interior scaling is screwed up in NWN when using miniatures and so I prefer to use another program for interiors. But caves do not suffer from this scaling problem in general - so your desire to use it is quite legitimate.
So you want to stick with NWN for interiors. You want to be able do it in the toolset, and you want to keep part of the map hidden from your players so you can reveal the areas only as you need to during play. What can you do?
Right
here is a very quick and dirty file package to help you. The attached file is simply a .rar file with a placeables.2da and 4 placeable models in it. For the most part, you’ll want to use the BlackPlane 10 or 15 model.
The model is exactly that – an all black model of a flat plane, 10m x 10m in NWN scale, i.e., the same size in height and width as 1 NWN tile. The number of polygons in the model is negligible so it will have zero effect on frame rate, no matter how many you use. It is difficult to conceive of a simpler 3d model.
The model is a placeable and is parented up from the Z=0 plane at various heights, corresponding to the model name. There are 4 in there – but you should pretty much be using the 10m or 15m high planes.
What this means in English is that this is a placeable that goes OVER a tile on your area map and you should centre it more or less exactly on the tile. When you do, all geometry below +15m will be hidden from view when the camera is positioned above this blocker plane at a 90 degree angle or so (provided you are zoomed up higher than 15m in height, which you almost always will be when in the toolset). Just think of it as covering over your underlying map with little square pieces of black tape, arranged in a grid.
A lot of work to cover up all your map this way with placeables like this? Not as bad as you think. Most people don’t know this, but the NWN Toolset supports standard ctl+c for copy and ctl+v for paste for all geom currently selected in the area window. It also supports marquee selection with the mouse – left click and drag. So after you place 4 of these down. Marquee select, copy – move cursor to next blank area – paste. Wash, rinse, repeat. Marquee select again as you go when you have an even larger number of placeables on the map if you like to increase the number of blockers you will be plopping down all at once so you can finish your task even faster. In no time flat, *poof* you are done.
You can put these in a hak if you like – if not unrar this into the NWN override directory and create or edit a placeable in the toolset that uses the BlackPlane 10 or 15 appearance. If you have any custom placeables, you will need to do some combining of the placeable entries in this placeables.2da to the one you are using.
Anyways, upshot: using this placeable tiled all over your map you should be able to prepare and obscure your map with about 5 mins or less of prep time (probably less). After that, during play, make sure you have the placeables tab selected in the toolset, then just select one of the black blockers as you need to as the party explores on the map and hit the delete key, revealing the tile and all of what lies below it to your player (ctl+z works for undo). Not absolutely perfect but it’s pretty good for a kludge. - Should be fairly intuitive for you to use during play with the toolset as the players explore.
Hope this helps.
