Is zoning a house with open windows useful?

[Barbie]

In an outdoor level is a house (H768 x W512 x B1024) that has 3 floors and 4/4/1 windows per floor. You can enter the house through the windows. Is it useful for the rendering engine to separate the inner house with some zone sheets or do I just create useless more BSP cuts with it?

[Higor]

Useful if:
- The portals completely hide the side surfaces of the windows (contiguous to outer wall)
- The houses have high poly/actor count inside.
- You want zone name.
- The outer part has high poly count and there's lots of inner areas.
- There's water zones and you spot a software rendering glitch.

The higher the poly count in the map, the better.

[Barbie]

The higher the poly count in the map, the better.

May I express that in my words: the higher the poly count the more useful is zoning that area.
Until now I was convinced that higher poly count in a map means lower performance.

[Higor]

Yeah I meant that.
A zone portal is a good way to avoid checking like 500 nodes, hiding loads of polys behind a zone portal is great practice, so the more polygons there are, the better is the usage of portals.
Just make sure the amount of portal polygons don't exceed 1/2 of the polygons behind it or you're actually adding checks.

Also, if you're forced to zone the house for some reason... might as well overdecorate it inside the house since you know the portal will take care of reducing the impact in performance.

[SzGergo]

Interesting question... i tend to believe, that zoning actually doesn't do much at all. One usually places a a sheet into a "bottleneck" in the geometry, and "forces" the program to make a cut where actually it most likely made one anyways... I mean, most if the time it works like some kind of superstition... It just feels right to place some zp in the doorway, since this is how it is done... and you twist some branches of the tree of the graph... but how would one tell if this version of the graph is like "more optimal" than the other one...
All this binary space partitioning theoretically looks so simple a nice when one just think about the concept, but in practice it is quite confusing if you think about a 3D instance, like a simple ut map... especialy when practical questions are asked, like, hey, what happens if i a cut is place here, is the tree gets wider, or is ti gets deeper, and srsly, witch is more "optimal" to compute...

[Barbie]

I can even go more into detail: If I want to put a zone portal into an opening (a window for example), do I have to put it on the inner side, the outer side, on both sides, in the middle of the opening or doesn't it matter, where exactly the location of the zone portal within the opening is?

[papercoffee]

I can even go more into detail: If I want to put a zone portal into an opening (a window for example), do I have to put it on the inner side, the outer side, on both sides, in the middle of the opening or doesn't it matter, where exactly the location of the zone portal within the opening is?

Putting it on the inside or outside exactly on the edge should have the same effect and "can" reduce bsp cuts. But also can it produce errors. I placed them in the middle of the opening... out of habit.
But my understanding of the engine is too shallow and I did it maybe wrong all the time. But till now it worked.

[Red_Fist]

I always go by 2 units overlap, and 2 units from face surface edges.

If the outside zone is really big, (or any bigger zone)
I figure the smallest zone should be as big as possible therefor chopping a little away from the huge big zone.
so I would put the brush 2 units away from the outer edge, or to make the largest zone smaller, even if it's a minuscule amount to chop from the larger zone.

The one brush per row of windows way I think would depend on how the BSP house was made, placing individual sheets give you more freedom to edit, one zone brush goes through a pile of brushes don't feel right, but if it's just one hole in the wall in a row and a small-ish sheet brush would be better to use one zone brush. IMO

[Dr.Flay]

Bury them in the BSP, is all you need to worry about.
In a window or door it would be useful to put it half way. If you have a transparent window or movable door, it should line up with that.

You can either zone each window manually, or make 1 big sheet per wall, and line it up inside the wall.