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I’ve been asked on many occasions how I come up with some of the brushwork in my maps, and those that have decompiled them wouldn’t see how they are actually created – which is a far simpler process then the mess of brushes that you see in a decompile.
So, in this regard I’ve decided to just write up the tricks that come with vertex manipulation that very few know about or use.
I know most of you avoid this tool because it gives you invalid solids all the time due to warped faces, but some good news here is that you can fix those same solids that were invalid with the press of 2 buttons 
There are three modes when working with the vertex tool:
- Vertices and Edges
- Vertices Only
- Edges Only
You can toggle between these views by pressing the Vertex Tool button repeatably or the keyboard shortcut SHIFT+V.
If your not familiar with vertex editing I suggest you take a quick look over SGT’s tutorial on basic vertex manipulation here:
Adding More Vertex Points to Solids (CTRL+F)
This is the most used option of vertex editing that I use and the easiest as well. I’ll be using a simple 64×64x64 brush crate for my examples. So make one yourself if your going to try out these different options.
To be able to add more vertex points you need to be in the “Vertices and Edges” mode which is the default mode – if not then your in the wrong mode so switch it till yours matches mine.
To add a new vertex to this crate select one of the edge points – Yellow Squares – on one of the 2D views and on the keyboard press “CTRL+F” and it will turn the edge points into vertex points. Quite simple to do really. Just remember that you need to select an edge point to create new vertices – you can do this in any of the views and select multiple ones at once.
Splitting Faces/Adding Edges (CTRL+F)
This is where you can fix any invalid solids you made due to the warped texture effect. I’m going to use the crate from the last quick example and move the new points around to get an invalid shape error.
As you can see there are the two top faces that are bending since one point is higher than the other. The way to fix this is via another keyboard command to add in an edge to split that curved rectangular face into two triangles so it will no longer be curved.
The trick here though is to split that rectangle in such a way that you don’t make a concave shape since vbsp doesn’t like concave shapes, only convex.
To add an edge between two points you need to select the two vertices for the new edge and then on the keyboard press “CTRL+F“. Now an edge line will be going between your selected vertices and the warped face will be gone.
With my brush if I cut from the top left vertex to the bottom right vertex it would create a concave shape to the brush and still be invalid, however if I cut from the top right to the bottom left it creates a convex shape that VBSP likes.
If your confused as to what convex and concave mean here’s a simple example:
Scaling Vertex Points (ALT+E)
Now this is where the real fun can start with vertex manipulation; its not a very well known command to scale up/down vertex point positions that you’ve selected but can be very handy and save a lot of time in many situations.
For example, you can see on the right how the three basic cylinders structure was changed so that their ends match up and are equal in size.
With normal vertex manipulation you would have to move all the points so that they matched onto the grid – and with cylinders of a large number of sides this can be difficult – and then move each point separately for the three brushes to match. This can be quite a lengthy process and not really desirable either.
But Through the scale option it takes all of 5 seconds to do.
How you do it is really simple, look at the face(s) you want to scale and then be sure to select all the vertices that make up the face in question – for my example thats the inner edges of the two larger brushes as we will not be changing the middle one.
Once you have the vertices for the face you want to modify selected press “ALT+E” and a new dialog box will pop up:
You can use the up and down arrows to change the value by .1 and the result will be shown instantly in your views or just enter in the value you need. Once done just hit Enter.
The circle icon thats displayed in all your views represents that of the origin for the scaling effect, so if you selected both the faces that need to be scaled at the same time then this origin would be halfway between the two brushes – meaning that they would go .5 both in width and hight along with moving half the distance towards each other in length. Doing each face separately will have them remain within their original position.
For my example the larger cylinders were 64×64 and the smaller one was 32×32 so the scale factor I used was “0.5″ to make the face 1/2 the size it was so that the large brushes come down on a cone shape to match that of the smaller cylinders faces.
If your trying to match up geometry of odd values, the way to get the correct scale is to take the larger size and divide it by the smaller size. Then your scale is 1 divided by that number
Hopefully I’ve sparked some ideas in people for making some interesting brushwork in their upcoming levels or some bizarre abstract ones
But just some final words of warning, this isn’t always the solution to the shapes your trying to create, use of the clipping tool will still be required due to the limited nature of brushes in that you can’t create concave shapes. There is also the problem in that vertex manipulation can cause distorted textures when its overdone so to speak, so keeping a good balance between clipping and vertex manipulation is key.
All the best with your future projects,
-Logan “Lost” Dougall
