Adding
Creating Default-Shaped Basic Additive Brushes

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The format of the majority of this tutorial is in an outline form, because it's based around the steps of Adding a Brush.

  1. If you have not already subtracted a cube, go ahead and do so.
  2. On the left, you can see several buttons that look like 3D shapes: a cube, a cylinder, a cone, three types of stairs, two types of sheets, BSP-based Terrain, and a sphere.
  3. Left-click on any of these buttons.  You will see that shape appear where your builder brush was previously (if there was no builder brush, it should appear at the World Origin - the center of the Unreal Universe.
  4. Now, right-click on any of the buttons.  You will see a small dialog appear with several options.  We'll start with the cube:
    1. The Cube is the basic builder brush of any map.  Though cubic rooms are often considered "noobish" or inexperienced by more seasoned mappers, much of your early mapping will consist mostly of linked cubes, and there's absolutely nothing wrong with that.
      1. The dialog that appears when you right-click on the Cube icon consists of prompts which allow you to control the shape and size of your cube.  The first three fields, Height, Width, and Breadth, allow you to enter a number (preferably a power of two, like 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, and 65536, all numbers which you will have to know from memory for efficient mapping [multiples of these numbers are also fine, like 24, 48, 96, 192, 384, 768, 1536, and 3072] and it might be useful to have a calculator handy while mapping) which controls how big each side is.  Width adjusts the Y-axis (up/down in the top view) while Length adjusts the X-axis (left/right in Top View) and Height adjusts the z-axis.
      2. The other options in the cube dialog include a Boolean (true/false) Hollow option, which is when you may want to change the WallThickness field.  (Boolean variables are noted in actor settings by placing a lower-case 'b' before the setting.)  Setting Hollow to true will create a double-cube as your builder brush, and it will subtract a solid box of the outer dimensions entered in the Z/Y/X fields.  A smaller box is essentially subtracted from the inside, with the same dimensions of the outer cube minus the Wall Thickness.  Unfortunately WallThickness applies to all three dimensions, and cannot be applied individually.
      3. The next options is GroupName.  Groupname simply groups certain brushes as they're created, rather than you having to add them later; with the default Groupname, a hidden group is created.  Groups will be discussed later; for now, don't change this option.
      4. Setting Tessellated to True simply divides the sides of the cube into visible triangles.  You will not want to enable this option unless you really know what you're doing, since the engine does this automatically anyway when it Rebuilds your map (I know you're getting tired of the "discussed later" interjections, but they're necessary for now) and it creates unnecessary 'fault lines' so to speak which can cause HOMs and texture misalignments.  In certain cases it can aid in creating a certain desired shape, but leave it alone for now.  This is, however, an appropriate time to address Triangle Theory.
        1. All Map Editors and 3D content creation tools use triangles as the base of construction, since they can combine to make up any other shape.  Unreal seems to support "Quads" or four-sided shapes but in reality when it calculates the environment it splits all quads into triangles.  When you open the Static Mesh browser, it will tell you (at the top of the viewport, in green) how many triangles each Static Mesh is; this is because the complexity of maps are measured in triangles (you can see how many you're viewing at a time by typing "stat render" in the console that appears when you press the tilde ('~') key or the mini-console that appears when you press Tab) that must be rendered by the engine.  Too many triangles slows down the map, but too few results in minimal detail.  About 60,000 triangles is average for the most visible triangles in a UT2004 map, and they max out at about 100,000.  Total triangles can range from 30,000 to 750,000 depending on the size of the map and the complexity of the meshes used.
    2. Next is the Cylinder.  This tool is often used by more experienced mappers in conjunction with the Vertex Editing tool, which we'll get to later.  Let's start with the obvious: Height affects how "tall" the cylinder is, and Sides affect how many sides it has.  No object in Unreal can be perfectly round, due to Triangle Theory, but with enough sides it can be simulated pretty well (though it's not recommended that you go above 16 sides).  Another useful aspect of this property is for the creation of Triangular brushes.
      1. Like the Cube, the Cylinder has a Hollow option.  If it's enabled, the InnerRadius must be smaller than the OuterRadius field, and it works the same way as a cube, except that the cylinder comes out like a tube (that is, there is no top or bottom).  Otherwise, the OuterRadius field controls the radius, or distance from the center of the cylinder directly to the circumference, and the InnerRadius has no effect.
      2. Groupname also works the same as it does with the Cube, and it will be left out of the remaining dialog descriptions.
      3. The last property is AlignToSide.  If this Boolean is set to True, the Radius will be measured to the center of an outer wall, rather than to the line between vertices.
    3. The Cone is very similar to the cylinder.  The only difference, in fact, is that there is an extra option, InnerHeight, which affects the height of the inside of a hollow Cone.  Hollow cones also do not have bottoms.
    4. The next tool is the Sphere/Tetrahedron.  The very best advice I can give you here is not to use them, as they do terrible things with the BSP.  It is strongly suggested that if you insist on using them, you make daily sacrifices to the UnrealEd Goblin.  That said, the main options here are Radius (self-explanatory I hope) and Extrapolation.  The latter determines how "sphere-like" the tetrahedron is; that is to say that it increases the number of vertices of the brush to make it more round.  UEd should crash if you even try to put in a number above 6, and it should crash if you add/rebuild anything with an extrapolation of 5 or higher.  If you must go above 2, I suggest you keep the smallest faces above about 8uu squared.
    5. BSP-based Terrain is a leftover from the days of UnrealEd 2.0 and earlier.  It has very little use these days, but you could use it to make cave-like structures I suppose.  The main idea behind this is it's a solid, two-dimensional sheet with lots of faces/vertices.  You can move these vertices around with the Vertex Editing Tool (discussed later) to make interesting shapes which were used to simulate terrain before the Terrain Tool and Static Meshes came about.  Again, be careful with this.  The main options here are Height, Length, and the amount of X/Y cuts you want.
    6. Sheets are nonsolid, two-dimensional brushes usually used for effects like spiderwebs or rays of light.  They're somewhat unfashionable, but if you want to use them the main options are Height, Length, and the axis it will be on.  Of course, you can rotate it to whichever axis you want, but it's just easier to specify first.
    7. Volumetrics are basically multiple sheets which intersect in a line at the center.  These too are leftover from UnrealEd 2.0 and earlier days, when they were used to make effects like fire and smoke.  They're pretty much completely useless these days since they've been replaced by emitters, but if you want to use them they have the same mostly self-explanatory properties: Height, Width, and the number of sheets.
    8. Stairs come in three flavors--curved, linear, and spiral.
      9.   Most stairs these days are actually Static Meshes, but the Linear Stair tool is still somewhat useful for convenience.  As a tip, the easiest way to create room for stairs is to flip the brush upside-down and give it a big first step.  That way, you get your stairs in their own separate little areas with plenty of room to run up and down them.  Also, remember that the ledge which the stairs lead to will function as a step if necessary, so you don't have to create that final step which brings the stairs level to the landing.  Be aware also that it becomes extremely tiresome to run up and down flights of stairs like those in office buildings that switch direction, so if you need such a staircase I strongly suggest using Movers instead.
      1. Linear stairs are the most often used, but they create lots of BSP lines if you put them all the way up against a wall, as you can see in Zone/Portal Mode in the 3D viewport.  I suggest leaving a 1, 2, or 4uu space between it and the wall/floor.  The relevant settings are the number of steps, the height of the steps, the depth of the steps, the width of the steps, and the extra height added to the first step.
      2. Curved stairs are out of use because of the BSP troubles they cause.  They're also annoying to use as a player, and they don't fit anywhere.  Relevant settings include step height, number, and depth, and the inner and outer radius.
      3. Spiral stairs are the same as curved stairs, except that they have the option to go multiple flights.  Don't use them unless absolutely necessary--static meshes do the job much better.  If you must use them, try not to make the area around them any more complex than it will be once you add the brush.
  5. Once you've picked your settings for your builder brush, click in any viewport, select the builder brush, and hit [ctrl] + [A] to Add it. You will see a solid object in the shape of your builder brush appear in the subtracted space in 3D mode, and if you move the builder brush you'll see a bluish brush in its place (blue is the color of Additive Brushes, just like yellow is the color of Subtractive Brushes).  Note that you can subtract space from this new solid, as well as add on to it.

When UnrealEd renders your map, brushes will be added and subtracted in the order in which you placed them into your map.  That means that because you first subtracted a room, then added the solid inside it, you will see a solid object show up inside the room.  If, however, you had first added a brush and then subtracted a room, the original Additive brush would have been subtracted as well.  You can rearrange the order of brushes and actors by right-clicking on them (to do this with a brush, you must do it either in the 2D viewports or the Wireframe Mode in the 3D viewport) and selecting Order.  A sub-menu will expand; choosing Move to Last will cause the brush or actor to be the last thing the engine renders, which is the same as making it as if that actor was the last thing you added into your map (so that its effects are visible) while choosing Move to First will do the opposite.  There is also a Switch Order choice, which is finicky and only works if only two actors are selected.

You can delete brushes by selecting them (left-click once on the brush in 2D view.  Once you learn about 3D Wireframe mode, you can select them the same way there, too) and hitting the Delete key.  You'll quickly realize that you won't see the effect of deleting the brushes in 3D view (except in Wireframe mode, but again, we'll get to that later...).  To fix this, you have to rebuild, which sounds scarier than it is (at first, anyway) but that will be briefly explained in the next tutorial.  If you just want to skip right to it and start playing the map, look for the bolded part about 1/3 of the way down the page.

Note: it is unadvised that you create overlapping additive (or subtractive) brushes, but in some cases it is considered an advanced technique.  Avoid it for now as much as you can.

You now know how to create basic additive brushes.  There is also an "Add Special" button which is used for more complex types of additions.  Also, there are various techniques associated with adding that may be useful to know, but don't really fit in later.  One of those is called Brush Sinking.  This involves aligning the surface of an additive brush which sits entirely in solid space with the surface of a subtractive brush.  The result is that the aligned surface of the Additive brush can now be painted ("textured" in UEd jargon) independently of the larger surface created by the subtraction.  This is occasionally useful for various purposes, including reducing BSP cuts which we'll get to later.

There are other techniques, but they involve the use of other tools which we haven't gone over yet.  I'll leave those to a later tutorial.  And don't worry, we'll be playing our map soon!

 

NOTE:  Many mappers in the community strongly believe that only cube brushes should be used in map construction because it often results in cleaner BSP cuts and they are easier and often more effective to use.  I am not of that party, but I strongly suggest you limit yourself to cube brushes, cylinder brushes, and in very limited cases, brushes created using the 2D shape editor which you'll learn about later.  If you need to make stairs, do it using a Static Mesh, or make it a lift, jumppad, or ramp instead.  Don't worry about being limited in the shapes you can make--you'll learn about Vertex Editing soon, and you'll be able to make any shape you want out of cubes at that point.

 

Review

  • [CTRL]+[A] adds a brush in the shape of the Red Builder Brush (RBB) if the RBB is selected.
  • There are 8 different default shapes that the builder brush can take, each with their own unique properties.
  • It is possible to rearrange the order in which brushes are drawn.  If you don't rearrange the order, they are drawn in the order in which they were placed in the map.
  • You must rebuild before the effect of deleting a brush will be visible in 3D view.

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