Create a Complex Brush Tutorial 3

From AAManual

Created by Tiago Freire

Important Note

Some of the tools described in this tutorial are extremely problematic and can frequently causes problems (they may cause BSP holes, none existing collision walls, and very frequently they crash the editor, probably one of the reasons they where not added to the first public version of the AAME), it is expected at this point that you have enough experience to tell what to and what not to do.

2D Shape Editor

The 2D shape editor is a very powerful tool with which to create custom brushes out of a 2D geometry.

Click on the red triangle on the top tool bar to open the 2D shape editor. For standard there is a pre-built square in the 2D tool view port, you can change the format by dragging its vertexes (no need to press ctrl key).

Before starting to use this tool, let’s try first to learn how to interact with it and learn what’s what and who’s who.

The grid is 2D only, you can also scale and change the grid unit just like in the regular UEd grid, it does not allow fractions of unit and to interact with it is very different.

To move around the grid you “click and hold the Right mouse button” and then move the mouse to drag the grid around.

To zoom in or out, you can use the buttons.

To drag vertexes around you “click and hold the Left mouse button” while over a vertex and move the mouse to drag it. Also hold down control if you want to select multiple vertexes.

Tools

Allows you to rotate the geometry 90º or 45º anti-clockwise per click.

Allows you to invert the geometry either mirroring in the X axis or Y axis.

Allows you to increase or decrease the scale of the geometry.

Adds an extra vertex to the selected line.

Removes the selected vertex.

Transforms the selected line into a cubic Bezier curve.

Transform the selected cubic Bezier curve in to a simple line.

This isn’t real 3D; however this will create a sheet.

This will creates a 3D geometry by revolving the 2D geometry around a certain axis.

This will create prism based 3D geometry by extruding the 2D shape.

This will create pyramid based geometry by extruding the 2D shape and merging it in to a single point.

This is a trapezoid based geometry.

Saves your custom 2D geometry

Opens a previously saved 2D geometry

Start a new 2D geometry

Vertex types

Geometry vertex

Selected vertex

Bezier point

Selected Bezier point

2D Geometry pivot point

Geometry centre relative to the geometry vertexes (drag this to move all geometry at once)

Line Types

Geometry line

Selected Geometry line

Bezier source line (usually to help tell which Bezier vertex goes where)

Selected Bezier source line

Let’s start by trying to click in one of the vertexes of the square, notice that when you select the vertex you also select one of the adjacent lines, you will only interact with one of them if you are trying to manipulate a vertex or the line.

If you click on the on the tool bar on top, it will split the line you have selected and add an extra vertex to make a more complex geometry.

You now have an extra vertex to manipulate in order to achieve your desired shape. If you select the new vertex and press on the button, it will delete the selected vertex and merge back the lines in to your original shape.

Let’s now try to make a curved line, select a line and press the button.

Notice that now we have blue lines and vertexes. These new blue lines and vertexes are parts of the cubic Bezier parameters of the curve.

The curve that it will create is not exactly a Bezier but it is a Bezier approximation.

Let’s try and move the blue vertexes.

You will notice that the line curves in segments; by default it is composed of 4 segments.

You can increase the detail level by holding “Ctrl” key and then right click on the line and go to “Segments>Detail Level>” and select one of the values as illustrated below. Remember, the more complex the curve, the more complex will also be your brush. Each segment you add is like having an extra vertex to the geometry.

If you press on the button the segment ceases to be a cubic Bezier curve and becomes a regular line.

WARNING:

The 2D shape editor is a very sensitive tool. Please be very careful while making geometries and make sure that:

1. All vertexes are always connected by 2 lines, and that every vertex is connected in a closed geometry.

2. Do not cross lines or merge vertexes.

3. Make sure that the lines always encompass the area inside.

You can add extra geometry units by going to “Edit” and press “Insert New Shape”. Thiss will add an individual new shape in to your view port to work with.

Building Options

To convert your 2D geometry in to 3D geometry you must chose one of the building options:

3D

- This isn’t real 3D; however this will create a sheet.

A simple dialog box will appear asking you in which axis you want to orientate your sheet.

Create 3D Geometry

- This will create a 3D geometry by revolving the 2D geometry around a certain axis. The pivot point is relevant to determine how broad the revolution will be (marks the spot where the revolution axis will be), make sure that the pivot point is all the way to the left or to the right of the 2D geometry or this will not work properly.

It will open a dialog box with the options:

Sides – Number of sides that your 3D geometry is composed of.

SidesPer360 – Number of side it is required to have to make a complete 360 revolution

Axis – Similar to the sheet

Create Prism

- This will create prism based 3D geometry by extruding the 2D shape.

A dialog box will show up with the following option :

depth – How tall your prism will be.

Axis – Already explained

Create Pyramid

- This will create pyramid based geometry by extruding the 2D shape and merging it in to a single point. The merging point is at a plane parallel to the base and at a relative position indicated by the pivot point on the 2D shape editor.

The dialog box will have the following options:

Depth – How tall your pyramid will be.

Axis – Already explained

Create Trapezoid

- This is a trapezoidal based geometry almost exactly like the pyramid based geometry described above, but with the difference being that a plane with the height caps the top instead of merging to a point.

The dialog box will show:

CapHeight – This will determine how tall your piece is, geometrically is at what height the pyramid will be cut to create the trapezoidal top.

Height – Virtual pyramid merging point.

Axis – The same has usual

Before finishing with the 2D shape editor, there is another feature that is actually more interesting then useful, in that the 2D shape editor allows you to add an image of your selection to the grid. However be careful THIS FEATURE OFTEN CAUSES UEd TO CRASH. I advise not to use it at all.

Freehand Drawing

The free hand drawing tool allows you to freely add vertexes around the 3D world to later extrude the shape in to a fully 3D geometry.

You start by choosing the tool, and then press "Ctrl + Right mouse button" to add vertexes. Notice that the newest vertex always connects to the previous one.

You can drag the already created vertexes around like dragging any other normal object. Do not connect the last vertex to the first, this task is done automatically by the UEd at the end of the drawing process.

Also be very careful:

1. Not to merge different vertexes.

2. Make sure that the resulting 3D geometry will not cross surfaces.

After your drawing is complete, Right click in any view port and select “CREATE BRUSH”.

Then all you have to do is to chose the Depth and you have your brush done.

Brush Clipping

The brush clipping tool is very handy when you want to split or to cut an already existing brush by a designated plane.

You will first start by adding a clipping marker by pressing Ctrl + Right mouse button on the position you want to place the marker, you can move an already placed marker like any other object. You must place 2 or 3 markers for it to work. Let’s try first with 2.

When you add the second marker you will notice that a line connects both markers and that there is another line that is perpendicular to it.

The line that connects both markers is representative of the cutting plane. The line that is perpendicular to the plane is called a “normal”, a normal is the perpendicular vector to the surface that by standard points to the outside of the geometry.

You can flip the clipping normal by pressing the button .

The normal will determinate which part will remain when using simple clipping.

If you click on the Simple clipping button, the brush will be cut and the half that hasn’t the clipping normal has its own normal it will be removed.

If instead you press to split , the clipping normal will be ignored and the both halves will remain.

Of course 2 markers do not compose a plane, you will need a third element to define a plane. With 2 markings the third element is defined by a perpendicular vector to the plane of the last 2D view port you have selected. Optionally you can add a third marker (make sure that the 3rd maker isn’t collinear to the other 2), the clipping plane will be a plane in which the 3 markers belong.

To delete the markers you can use the button .

Good Mapping!!