Angled arch issues

[FPSMoto]

Hi, I'm working on a new map in hammer and have come across a few issues with arches or even with the clipping tool.

I'm trying to create a half-circular shape 576 units circumference that has an angle at the outer part of it 64 units thick with a height of 72 units.

The first thing I tried was making a 90 degree arc arch that is 288 units on each side using the attributes below:


I then tried using the vertex edit tool to bring the outer-top points to the outer-bottom points, merging the vertices. I then copied the arch so i could turn it from 90 to 180 degree arch, which looks like this:


The problem is when I compile the map when I look at it in game. It ends up having jagged edges in parts of some of the brushes:


So I then tried a different method of manipulating the vertices and that was first clipping each brush down the middle like so:

(I also tried alternating each clip so it would go from the outer edge to the inner edge, then the adjacent arch point would get clipped from the inner edge to the outer edge, rinse repeat until I hit the edge of the arch.)
Which gave me this result in hammer:

This almost works the way I want, but there is some tearing caused by this method when viewed in game:

I've quadruple checked all my vertex points to make sure I aligned everything properly and all points line up to the grid.

So what I've had to do as an alternative was scale the top vertex points to 0.5 to end up with this:

But when I do this, the inner vertex points do not line up with the grid. So if I wanted to make a flat platform that is clipped to the shape of the inner part of the arch, there will always be some overlap:


Does anyone have any tips/suggestions/advice to correct these issues?

[Corigami]

The last section of this tutorial http://www.interlopers.net/tutorials/31415 covers what you're trying to do but you shouldn't be having any issues after triangulating your arch like you did in your second step. I'd try recreating it from scratch again, but if that doesn't work see if starting with a full circle arch and deleting the 3/4 of it you don't need fixes the problem. Otherwise the 576 unit circumference might be causing the problem, hammer is obnoxiously touchy about complex brush geometry that isn't clean powers of two. You might have to scale it down a bit to a 512 unit circumference and 64 unit wall width.

[FPSMoto]

Ok thanks. I will try that. The main problem with that is 512 units would be slightly too small and 1024 would be way too big for what I'm trying to accomplish. I'm remaking an old TFC map for a HL2 mod called Fortress Forever. I'm thinking it may have something to do with the actual angle itself as I had someone help me test this and they were able to get it to work with a 45 degree angle on each side of the arch which means they used a thickness of 64 and a height of 64. The map I'm making has 3 or 4 different sizes of these angled arches I want, ranging from around 400-600 units wide.

Since I don't want a 45 degree angle (as that would prevent a player from standing on the surface without falling off), I'll likely go with a wider angle using 32 unit height which is still power of 2 and let you know if it worked or not.

[FPSMoto]

I tested this further and found the length of the arch has to be a power of 2 like you said. The angle/thickness doesn't need to be a specific angle so I was able to use 2x 256 quarter arches 64 units thick, 32 units high and I just added an additional brush in between the two arches so it matches the size I need.

Thanks for the help.

[Gambini]

You do know about displacements right? I see you´re trying to do lot of uneven structures with brushes. That will work much better with displacements or models.

[FPSMoto]

Yeah but to make a displacement from a flat square surface to a flat circular surface isn't easy, then making the sharp angle to get a similar effect to how I am doing it with arches I really don't know how to do. I know about subdivide, but not enough to get a perfect shape like I want.

[Riomaki]

Well, you can fudge the displacements quite a bit along the edges. It doesn't have to be perfect - in fact, it really shouldn't be if you're aiming for realism. If you have a 90 degree turn build from 4 displacements, it will still look reasonably smooth if you mold it right. Plus, since your road will take up a lot of screen real estate, painting on the displacement is a huge benefit for breaking up the texture monotony.

There's a reason why Valve uses displacements in almost every instance like this (see the White Forest Inn level for a good example).

[Corigami]

There are third party tools like Twister for generating complex geometry with displacements, but in this case brushes are the easiest and most efficient way to do it. I don't know of any third party displacement tools that will create this shape exactly, and even if they did there would be a lot of unnecessary geometry while using brushes allows you to use the minimum. This shape could be modeled, but for something this large using brushes which receive lightmaps will probably produce the best lit results. Displacement roads are only ideal in some situations, and valve uses both displacements and brushes to make complexly shaped roads depending on the circumstances (look back at the coastal road maps to see triangulated brush arches in use)

[FPSMoto]

Well after another few compiles, I'm still having problems with this issue. The above resolution I posted before ended up not working and causing tearing like what happened originally. I also tried displacements but couldn't get it to work the way I wanted. I could get the flat circular shape down but not the angled curve. (i made an octagonal shape with brushes and subdivided them all together to make the circle)

So basically I'm grasping for straws on this and about ready to give up. I saw someone mention this was for a road but it is not. This is what I'm trying to make:


The only issue with the way I went with that worked is there is overlap when I try to make the flat rounded surface on top to act as a platform. This doesn't cause issues in game, but does cause me to get a lot of those WARNING: Cluster portals saw into cluster errors which isn't all that big a deal because all it does it cause hammer to compile more slowly. Once I get the architecture down, I can simply make a user visgroup and hide them all until I'm ready for a full compile so when I test other parts of the map, it won't take forever.

I did find the Twister app when I was researching this issue but I wasn't aware it was able to be used for stuff in hammer. I might have to check that out. Thank you.