Curved + Arched Brush

Mar 20, 2012
391
806
I am currently working on a map that includes an arched tunnel that makes a curve. Here is the start of the tunnel (the straight portion):
http://cloud.steampowered.com/ugc/541798647256916617/E170110232F7F9986F41CDA4098971B73FE8C51F/

Now, here is the curved part:
http://cloud.steampowered.com/ugc/541798647256906191/073CA1F8426284AEE94BD61079058A05F49D56D1/

So, I want the curved portion to be arched like the straight portion. I've tried individually moving points via vector editing and I can't seem to get it right. Does anyone have any suggestions how I can go about turning this into an arched curve?

Thanks in advance :)
 

tyler

aa
Sep 11, 2013
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4,621
I would use displacements. There may be a way to basically subdivide it out... I don't know. I was even going to suggest using Twister, but I'm not sure it can do that.

You've got me wondering what the curves like this in game do--I'm guessing just vertex editing?

Maybe vertex editing is the way to go--just use another arch as a guide?

I think, actually, I would do something other than a curved curving curve.
 

grazr

Old Man Mutant Ninja Turtle
aa
Mar 4, 2008
5,441
3,814
I'd vertex edit some reference brushes into place and then displace a... displacement into place.

P.S. You'll only need a brush every other section (checker pattern) as each brush edge will provide the necassery edge for reference. This'll save you some time.

Complicated geometry like this has a habit of getting itself nudged off the grid by decimal points and a displacement just looks smoother anyway. It's probably also prudent to make the brush slightly longer than its base attributes when curving it like this as otherwise one edge will appear overly stretched.
 
Mar 20, 2012
391
806
I think, actually, I would do something other than a curved curving curve.

yo-dawg-xzibit-48.jpg


Anyways. I checked out Twister - it looks like I might be able to work in a curved arch. I'm a bit worried that Twister is outdated (the last update was a few years ago). I don't really want to increase my daily hammer crashes.

The reason I wanted this curve is because the walls are going to become glass, and I'm going to cover it with an animated water texture. It's essentially going to be a BioShock-esque glass underwater walkway.

I'm continually trying to find different ways to tackle it via vertex editing. It starts off fine, but I get mangled by the fact that, because each subdivision of the curved wall is off the grid between end-points, I can't align it properly with the arch pieces. Thus I get gaps or overlaps. Considering I won't be using this to seal anything, it shouldn't matter, but I'm a stickler for details and a perfectionist.

I'd vertex edit some reference brushes into place and then displace a... displacement into place.
Hmm. I'll give this a try tomorrow. Displacements might be the way to go with this.
 
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tyler

aa
Sep 11, 2013
5,102
4,621
Twister is old, but it just makes a valid object however you want. If you use it, definitely have it output a displacement rather than brushes or you'll get 5000 microbrushes.

Maybe you should model this tunnel though.
 
Mar 20, 2012
391
806
Donut, your username is rather appropriate for this discussion. That is all.

That's funny, because this area was originally in the shape of a donut (somewhat). However, I recently changed the design to something more practical to play in.

So, I tried the displacement method. After about 40 minutes, I could only get one piece of the arch to look semi-okay. I think I'm either just going to model this or change the way I present this tunnel.
 

Skibur

L1: Registered
Dec 6, 2011
20
13
Three ways,

1. Make a Torus brus, cut it into the pieces you like, invert the surface.

2. Use displacement tool.

3. Export the scene into .dxg file, use a 3D program to model the object you wanted, then export it through the following options.
a. Export it into .SMD, convert it using notepad or other similar compiling programs to get mdl.
b. use wall worm plugin for your 3d program.



Wish you luck on that!
 

A Boojum Snark

Toraipoddodezain Mazahabado
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Nov 2, 2007
4,775
7,669
I could just make the displacement if you want. What is the inside radius of the corner? I could show you how to do it with pictures, but that would mean making one so I might as well do what you need during the process.
 
Mar 20, 2012
391
806
I could just make the displacement if you want. What is the inside radius of the corner? I could show you how to do it with pictures, but that would mean making one so I might as well do what you need during the process.

That would be wonderful if you are up for it. I don't want to barge in on your time.

I hope these are the measurements you wanted. I wasn't sure which inside radius you wanted. The inside corner is 96 by 96. Including the inner-wall, it's 112 by 112. The entire thing is 320 by 320.

Vertically, it's 64 from bottom side of the ceiling, 96 from bottom to top side of ceiling.




Sorry for the crappy print screen pictures. Hopefully they help.

And if it's too much of a hassle, don't worry about it.
 

A Boojum Snark

Toraipoddodezain Mazahabado
aa
Nov 2, 2007
4,775
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pic1.PNG


Start with template circles for the inner, outer, and roof curves. Here the walls are 8 sides per corner (32-side cylinders) and the roof is 8 sides (16-side cylinder). This is different than what you have, but using displacements means we are restricted to multiples of four.
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pic2.PNG

pic3.PNG


Next we need corner templates at the radius of each joint in the arch. These (and the others) are best made individually rather than cloned and resized because the brush-generation algorithm will place all the vertexes on the grid but resizing won't always do so. Zoom in as far as you need to precisely measure the distances.
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pic4.PNG


Next make a displacement where the base of the arch should be, facing up. The end result will be inverted to make a roof, but displacement faces only show in 2D if they are facing the viewport and we will be working in top-down. This is a power 3 displacement (8x8) to go with our 8 sided corner/arch.
It isn't strictly necessary to make the brush angled with the corners at the corners of the curve, but it will result in less vertex movement being needed in the next step.
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pic5.PNG

pic6.PNG

pic7.PNG


Now begins the tedious part, using the Paint Geometry set to 1 unit and spatial turn off, move each displacement vertex to match up with the corresponding vertex on the template circles. You need to start at the outer edge so you are spreading the vertexes away from each other, instead of overlapping.
Grouping the templates can help with keeping the lines less confusing, since grouping gives brushes red/yellow line colors.
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pic8.PNG

pic9.PNG


Next switch to the Z axis and set PaintGeo to the height of your arch and go down the middle row lowering it. After that you need to measure the height(depth) of each vertex along the arch and move the two corresponding rows on the displacement.

pic10.PNG


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It would be possible to save some time (do half, mirror and rotate) and get slightly less distorted texturing by using more than one displacement brush along the "length" of the curve so the verts near the center aren't moving as far. However depending on the size and placement, this may end up with displacement verts at fractional grid units. This won't cause an error, but it means lining them up with the templates will be harder, though anyone is unlikely to notice the displacement being fractions of a unit off from "perfect". Because my brush had 45 degree angle and the grid was on 8 all verts landed on-grid (8x8 displacement divides into multiple of 8 grid size).

>> VMF <<
 
Mar 20, 2012
391
806
They need to put another option right next to "thanks"...

It should read "worship."

:O

I'll give this a try in a bit. Thank you for going into such great detail. Not only will this help me get the shape that I want, but it will give me a better understanding of displacements in general.

In other words, you da bomb, Boojum.

P.S. Yeah, I did realize when I started trying to do my own displacements earlier that I needed to bring the archway down to 8 sides instead of 10, to correspond to the 3rd power displacement grid.