Invisible walls?

[brian edge]

What is this invisible wall from? I can't walk down or up the ramp. It seems to appear if I add a piece of BSP around it.

[Bi()ha2arD]

can you select it? did you add a blocking volume there? are your brushes aligned properly?

[brian edge]

Originally Posted by Bi()ha2arD

can you select it? did you add a blocking volume there? are your brushes aligned properly?

No, I can't select it and I didn't add any blocking volumes. It seems to be something with the BSP brushes. I had to re-add a large rectangle on the top right of the view in the picture. The rectangle was separated from the entry in the picture by quite a few other BSP models, but it somehow created an invisible wall because it was slightly above a similar rectangle beside it. When I moved it down by one small square, the invisible wall disappeared.

The same problem has happened before on this map, with other shapes in other areas of the map. It's fine now, but I'm just trying to see if there is a way to prevent it, because it's really annoying.

[Odedge]

Originally Posted by brian edge

but I'm just trying to see if there is a way to prevent it, because it's really annoying.

Invisible walls usually happen when there is a BSP error. It can happen when your BSP isn't snapped to the grid, you have some complex shapes, or possibly intersecting brushes.

BSP is not that flexible (compared to meshes), but if you follow "the rules", you shouldn't have any problems.

[brian edge]

Originally Posted by Odedge

BSP is not that flexible (compared to meshes), but if you follow "the rules", you shouldn't have any problems.

So I've noticed. Are there any sites, or a list somewhere, that explains any "do's and don'ts" of using BSP, is it all trial and error?

[Odedge]

Originally Posted by brian edge

So I've noticed. Are there any sites, or a list somewhere, that explains any "do's and don'ts" of using BSP, is it all trial and error?

You can check the BSP section of my UT 3 tutorial list or this one from Hourences or one that I wrote (for R6: RavenShield).

My top 3 rules.

1. All BSP needs to be snapped to the grid (every BSP should always be snapped to the "1" grid". Never to to manually align them up to the grid.

2. It's best not to intersect brushes. Think of them as actual building blocks (like Legos).

3. Keep their shapes simple. For really complex shapes, static meshes are the way to go.

[brian edge]

Thanks for the links. I pretty much followed your top 3 rules so far. I guess the invisible wall appeared when one of the blocks wasn't snapped.