1. Creating Interesting Geometry
2. The Vertex Tool

Introducing Vertex Manipulation

Vertext manipulation allows us to modify the shape of a brush even further. Instead of being confined to working with shapes that have six surfaces and eight corners, we can create geometries in any shape we want (with a few exceptions, but we'll get to that later).

A vertex (or plural, vertices) is a corner of a solid brush. A cubic brush has eight vertices. An edge is a line between two vertices which, when moved, will change the position of its two associated vertices. A cubic brush has twelve edges. A face is one flat surface of the brush. Each cubic brush has six faces, and each of these faces has four vertices and four edges. Review your geometry if you don't understand what I am talking about here. With the Vertex Tool, we can create more vertices along an edge of a brush, and we can also merge (or destroy) vertices from a brush.

Just like we can rotate through different editing modes with the Clip Tool and the Select Tool, we can also rotate the Vertex Tool modes by pressing Shift-V repeatedly. The first mode displays the handles for both vertices and edges. The second mode displays just the vertex handles, and the third mode displays just the ones for the edges.

Building an Arch

Let's return to the doorframe that separates the indoor and outdoor areas of our map. We will change the rectangular doorframe to an arch, using vertex manipulation.

First of all, create a cylinder with 16 faces that has the same width as the doorframe. To do this, select the Block Tool, and choose "cylinder" under "Objects:" and set "Faces:" to 16. When you're done, rotate and position it so that it goes through the door as illustrated below:



Select the cylinder, it will serve as our guide when we build the arch. Next, create a regular block (non-cylinder) brush as shown below. You'll have to change the "Objects:" setting of the Block Tool back to "block" instead of "cylinder".



Use the Clip Tool to section the block vertically along each corner of the cylinder, you may have to increase the Grid density to cut more precisely:



Now, activate the Vertex Tool (Shift-V) and click on the bottom left edge of the first sectioned block in the 3D view. The entire edge should be selected (the yellow handle turns red):



Drag the red handle in the x/z view all the way until the edge is touching the top of our cylindrical guide brush. When prompted with "Merge vertices?", choose "Yes".



Repeat the same process until all the edges are superimposed with the corners of the cylindrical guide brush. Notice that you have to drag two edges for each sectioned brush, and it may be easier to zoom in to manipulate the vertices more precisely.



Now, we have half of the arch completed. Select the cylindrical brush and delete it. Ctrl-Click all the sections of the arch brushes to select them, and press Ctrl-G to group them together into a single brush. Texture it with the same texture as the surrounding wall if you haven't done so already. And now is a good time to save our map before something happens to it.



We don't have to do the same task all over again for the other half. We'll Shift-Drag the half-arch with the Select Tool in the 2D view to duplicate it, and rotate it 180 degrees in the x/y view along the z-axis.



To group these two halves into one brush unit, we'll select them both and press Ctrl-G to group them together. Ain't that pretty!

Making a Broken Wall

In learning how to construct the arch, we learned how to merge (or destroy) vertices. We can add new vertices also. To demonstrate this in an example, we'll create a broken wall in our firstmap.

Make a brush in the outdoor area of the map, directly against the wall of the arch, with dimensions 16x160x128. If you haven't noticed already, you can read the dimension of each brush when it's selected at the status bar near the bottom of the screen.



Select it with the Vertex Tool, and click on the upper two edges. To select both edges, you need to click on the first edge handle first, and then Ctrl-Click on the second edge handle.



Press Ctrl-F to divide the face into two halves, thereby creating two more vertices and three additional edges (see if you can find all the new edges in the picture):



Drag the out-extended edge downward until it almost touches the ground.



Duplicate this wall, flip it around 180 degrees, and modified the edges and vertices until it looks like the picture below:



That's it. Now you can use your imagination to create anything you want with Hammer (Well, not quite. See disclaimer/exception in the section below). And to test your new skills in vertex manipulation, try to make the circular window shown below. It should not take more than three steps, and you should be able to do it in less than five minutes.

Pitfalls to Avoid

We cannot create a brush that has a concave shape. Doing so would result in an "invalid geometry" compile error. This is because of the way VRAD was designed. Light bounce calculation cannot be done on this type of geometry, so us mappers must always avoid it.

Valid (convex) geometry

Invalid (concave) geometry

To Undo operations done with the Vertex Tool, you will have to first exit vertex edit mode by choosing another tool.

This concludes our vertex tutorial, and with that you are now officially an intermediate mapper (w00t! Not a n00b anymore!).