Gaps in brush-work

I’ve got a problem with one of my maps. A small gap appears at the intersection of my walls.
I know it has something to do with the wall brush being shifted during compile so the wall face is nolonger in the proper spot. I also know that you can see through it because the engine automatically changes the side of the wall to a nodraw texture, and with the main face shifted, the effect of the side on joining brushes is visible

This is what it looks like in hammer:

The red line indicates the brush face when in-game and the blue circle indicates the resulting ‘gap’

How do I correct this?

Holy crap get on the grid.

Not sure, but it happened with me. Everything was sealed. No leaks or anything. So any response I’d love also.

Its an invalid solid most likely.

invalid solids will automatically be shifted on compile, granted that you have not already used Alt+p to find the invalid solids.

PROTIP: for rotated brushes, use vertex manipulation and the grid!

The weird thing is that the solids that are being shifted are on-grid

Also, doesnt source round to the nearest .5 units? or is it the nearest unit.

This may be off grid, but it sits fine in game.

It’s off grid for a reason, I can’t get it to look as good on-grid.


By looking through that strange off-grid piece, you can clearly see that the main wall is… well I don’t know, messed up.

Yeah it doesnt matter if you cant make it look as good. in game it will look better because its not fucked up

Well, that’s true, but from the last picture I posted you can see that its the plain, flat-surfaced wall that’s fucked up; not the series of brushes that keep being referred to

Here it is again, outlined. Why is it doing this? This whole side should be flat.

its doing it because its an invalid solid!

The flat wall is an invalid solid?
Perhaps that’s true, but it just seems so unlikely; it’s basically a plain brush, with two sides turned out to make a trapazoid. There’s nothing to it; no funny angles, it’s not off-grid and it’s even a func_detail so it compiles smoother.

How do you get on the grid with a diagonal, especially without horribly deforming the brushwork?

The line doesn’t need to be on grid, the corners do.

And generally one puts the lines on a ratio so that they are easy to make seamless lines.

Good news, it isn’t an invalid solid. I don’t have any invalid solids in my map.

Now that that’s cleared up, anyone know why my brush is acting up like that?

Try snapping the CORNERS to the grid.

I was worried about doing that because I didn’t want to mess up the brush work, oddly the only side-effect was in the brushes next to them. There were no compile problems, they were valid brushes despite them being off grid [because I made them on-grid and then rotated them] and they were properly symetrical.

I finally went through and adjusted them on-grid and the problem seems to have gone away.
Any reason why off-grid brushes would affect the brushes joining it rather than itself?

not sure exactly, but I do know that if you save a map with a sphere primative in it (that’s off grid), you will see that the vertices will move ever so slightly to the left or to the right. I’m guessing that the compiler did something similar to this

Gah, it’s because of your rotation, all you’d have to do is tweak with that. Use CTRL+M for the transformation tool, and using a calculator for assistance in setting the angles for the brush

Rounding error in the saving to .vmf format.