We're not actually going to draw anything in this lesson, but I'll show you how you can speed up working with BSP by using the Group Window.

You'll notice as your maps grow larger that it becomes increasingly difficult to select particular brushes to work with. Also, 3-D rendering becomes slower the more brushes you have in your map. In small maps you'll hardly notice any slow down, but the lag seems to grow exponentially as your map grows. This isn't the fault of BSP; it just takes longer to draw all those brushes. We need a way to hide brushes in areas of the map we aren't working in. That way, we can concentrate on a specific area without having to suffer the overhead of all those other brushes. Fortunately, BSP provides a convenient way to do just that: Grouping.

In BSP, you can select groups of brushes and make them invisible to the editor. This can speed things up by not having to re-draw all those brushes all the time. If that were all you could do with groups, that would be great, but there's more. You can copy and move entire groups as one. You can export and import groups between maps. The usefulness of groups is enormous. And you get all this power without much work on your part. (That's the really great part).

So what do you say we get started. Load up a map (any map, it doesn't matter). Now, pick a part of your map that you aren't currently working on, like a room that you are finished with or something. Select all the brushes that make up this area. Since you're essentially done with this area, those brushes just get in the way when we're trying to work on other areas of our map. Let's make them into a group and turn them invisible.

It's probably going to be easiest to select these brushes in the 3-D wireframe view, so switch over there and move your camera position around so you can select all the brushes you want to group together. Remember that in the 3D view, you can select objects by just clicking on them. Once you've got a few brushes selected, switch over to the Group window.

Right-click on 'None' and the following menu will pop up:

Select 'Add new group...' from this menu. A box will pop up and ask you for a name. Type some meaningful name for the brushes you are grouping together (without quotes) and click on OK. A color dialog box will pop-up. Pick a color you want to use for this group and click OK again. Voila! You've just created a brush group. Your new group appears in the list of groups in the Group Window. If you look in the editing windows, you should see the brushes in your group have changed to whatever color you selected for this group. This lets you know they are grouped. Cool, eh?

Now, in the Group window, make sure your new group is selected in the group list and right-click on the Group Window again. This time select 'Visible'. Now your group has disappeared from view. Relax, it's still there, you just can't see it. (Re-select 'Visible' on the context menu if you don't believe me). These brushes will not show up in any of the view windows now, including the 3-D textured preview (this is where the speed savings really shows up)

Of course, you can turn off multiple groups if you want. Personally, I like to turn off all the groups except the ones immediately surrounding whatever area I am currently working on. That way I can focus just on that one area.

That's all you need to know to use groups, but you might be wondering what some of the other options on the context menu do. Well, here's what I know about them:

The name of the current group shows up in each command, so you know what group you are working with. In the above screenshot, it's [None].

Now, there are a few things you'll need to know to make grouping work well for you:

First, when you draw a new brush, it will be assigned to whatever group is currently selected. This is handy, but if you're not careful it's easy to draw a brush in a group you weren't expecting. That is one reason for the 'Move Selected To' option - so you can change a brush to another group after it's been drawn.

Next, whenever you copy a brush, the pasted copy get's assigned to the current group, regardless of whatever group the original copied brush belonged to.

And finally, when you load a map, all groups are set to the visibility status they had when you saved it.

Go ahead and play around with the grouping window to get comfortable with it. You can make as many or as few groups as you want. Just remember that on larger maps it really comes in handy to be able to hide a bunch of these. Here are the groups I used for a map I did for another lesson:

Well, that's it for this lesson. Hope you find groups as easy and useful as I have. Next time I'll go over a few more triggers, including the exit trigger as we make an exit from our map. See you soon.