Exercise 1: Creating a One-Room Map

Setting Up the Document
Importing Textures
Creating a Floor
Adding Walls and a Ceiling
Adding Textures
Setting the Start Position
Exporting the Map
Testing the Map

Setting Up the Document

When you launch Sketchup, you're presented with a new, empty model. However, depending on how your Preferences are set, the one you get may not be set up the most convenient way for MarathUp. So close the default document window and open the Preferences window. (It's under the SketchUp application menu on MacOSX; I'm not sure exactly where it is on Windows.)

Set the Template to "Inches (Woodworking)-3D". Now close the Preferences window and use File>New to create a new document. You should get something that looks like this:

We won't be using the set square, so click on it so that a highlighted box appears around it and press the Delete key.

MarathUp assumes that the model is drawn to a scale of 1 inch to 1 world unit, so the next thing we need to do is check that the units are set up correctly. Choose the Windows>Model Info command. You should get a dialog like this:

Make sure the Format is set to Architectural and Inches. For now, turn on length snapping and set it to 1 inch. This will make it easy to build structures in multiples of world units, which we'll want to do in the early stages of constructing our level. We can change it later when we come to add fine details. When you're done, close the Model Info window.

Importing Textures

Although the textures applied to the model in Sketchup don't have to be the same as those used by Aleph One at playing time, it's helpful if they're at least similar so that you can see how the level will look. The easiest way to do this is to extract the textures from the Shapes file using ShapeFusion or otherwise, and import the resulting image files into Sketchup as textures.

MarathUp includes a script which will import a collection of textures and set them up in the right way for the exporter to use. It assumes that the image files for each texture set are in a folder named Walls<n> where <n> is a number from 1 to 5. Within the folder, the image files need to be named so that they appear in the right order when sorted alphabetically. Applying ShapeFusion's Export Bitmaps command to a wall texture set will produce a suitable set of files.

The MarathUp distribution comes with one set of wall textures to use as an example, in the Shapes/Walls1 folder. To import these, choose Plugins>Marathon>Import Textures and select one of the .bmp files in that folder. (You're really specifying the whole folder, but Sketchup doesn't currently provide a way of letting you choose a folder.)

To see the textures, choose Windows>Materials to open the Colors window:

If they're not already selected, click on the "brick" icon at the top, and choose Colors in Model from the drop-down menu. You should see the imported wall textures.

To see how the wall textures have been set up, double-click on one of them to open up a further pane at the bottom of the window:

You'll see that the name of this texture has been set to "17-0". That's because the "Walls 1" texture set is collection number 17 in the Shapes file, and it's the first texture in that collection. This is how the export script knows which texture it corresponds to.

Also, the Width and Height of the texture have been set to 1", or 1 world unit. This is not required by the export script, but it ensures that the texture will appear the correct size when you place it in the model.

The Width has been made negative to mirror the texture, so that it will appear the right way around when applied to the back of a face. Due to the way MarathUp models are constructed, you'll be texturing the back sides of faces almost all the time.

Important: When you've finished looking at the lower pane, click the Close button down the bottom to close it! If you don't, you run the risk of accidentally modifying the texture later.

Creating a Texture Library

Rather than importing all the textures into every level you create, it's handier to put them in a texture library. To do this, make sure you have "Colors in Model" selected, drop down the List menu at the bottom of the Colors window and choose Duplicate. Give the new list a suitable name, such as "M2 Walls 1", and save it.

Now you have a copy of the Walls 1 textures stored away where you can easily use them in any Sketchup model. Once you've done that, you can delete them from the model itself. To do this, switch back to "Colors in Model" (the "Home" button at the top is a shortcut for that), and from the List menu choose Purge Unused.

The advantage of doing this last step is that only the textures you actually use in the level will be stored in the Sketchup file. Since Sketchup stores its textures totally uncompressed, this can make a big difference to the size of the file.

Before leaving the Colors window, switch to the "M2 Walls 1" texture collection that you just created (or whatever you called it), so you'll be ready to use them in what follows.

Creating a Floor

Now we can start building a level. Choose the Rectangle tool

from near the top of the tool palette. Move the mouse over the model window until it's near the origin, where the three coordinate axes intersect. It should "snap" to the origin and a yellow dot appear. Click and drag a short distance so that a rectangle appears, aligned with the horizontal plane (red and green axes). The Dimensions box at the bottom right corner of the window shows you the size of the rectangle as you're dragging it out, but it doesn't matter what the size is -- we'll fix it in a moment.

Now, before doing anything else, type 3,2 on the keyboard and press Enter. The rectangle will change to the new size (in inches) that you have specified.

(Note: If you've done something else in the meantime, you may have lost the chance to type in the dimensions. If that happens, Undo until the rectangle goes away and start again.)

If it looks as though the rectangle has disappeared, that's because we're zoomed too far out to see it easily. To fix that, click on the Zoom Extents

tool near the bottom of the tool palette. This re-sizes the view to fit the model. You should now have something like this:

The face we've just created is going to become the floor of a Marathon polygon. We will need to build upwards from it, so use the Pan tool

to drag the view downwards so the rectangle is near the bottom of the window.

It's probably a good idea to save the Sketchup file at this point, under some suitable name such as "Example1". You may also want to save after successfully completing each of the steps below, in case of accidents.

Adding Walls and a Ceiling

Now switch to the Push-Pull tool

, click in the middle of the rectangle and drag upwards. This extrudes the 2D face out into a 3D structure. You'll need to drag almost all the way to the top of the window before anything happens, and then it will snap out to a height of 1 inch (because that's the snapping distance we set in the Model Info window).

We now have six faces making up a rectangular block. When we export the model as a Marathon level, these will be translated into a single Marathon polygon. The top and bottom faces will become its ceiling and floor, and the side faces will become walls.

Before we can usefully export it, though, we need to apply some textures.

Adding Textures

A small problem we face here is that the textures need to be applied to the inside surfaces of the faces we've created, because that's where the player will see them from. To do that, we need to temporarily hide at least one face so we can get at the interior.

Using the Selection tool

, click on the top face of the block (the ceiling) to select it. The face is displayed with a dotted pattern to indicate that it is selected. Now choose Edit>Hide. The ceiling becomes temporarily hidden, resulting in a view like this:

To get a better view, switch to the Orbit tool

, click in the window and drag downwards to rotate the view a little until you get something like this:

You'll notice that the inside surfaces are displayed in purple. Each face in Sketchup has a front and a back surface, and the default colour scheme displays the front surfaces in white and the back ones in purple. This is important, because the export script assumes that the back surfaces of floors, ceilings and exterior walls face towards the inside of their respective Marathon polygons. The fact that all the inside surfaces of our block are purple is good, because it means the faces are the right way around.

(If you ever find you have faces that are the wrong way round, you can fix them by selecting the faces, control-clicking to bring up a contextual menu, and choosing Reverse Faces.)

Now we're ready to apply some textures. If the Colors window is not already open, bring it up using the Windows>Materials menu command. (It's a bit confusing -- the menu command is called "Materials" but the window is titled "Colors".) Make sure that you don't still have the lower pane of the Colors window open. If you do, click the Close button at the bottom. Also, if you don't have the texture library that you created earlier in view, select it from the menu at the top.

Now pick a texture that you'd like to apply to the walls and click on it. This will automatically switch you to the Paint Bucket tool

. Click on the insides of the walls to apply the texture to them.

Now use the Orbit

and Pan

tools again to rotate and position the view until you can see the insides of the other two walls. Just for variety, let's choose a different texture to apply to them.

While we're at it, we'll also apply a texture to the floor.

Finally, we need to texture the ceiling, but we'll need to make it visible again first. Choose Edit>Unhide>All, then rotate the view upwards (

) so you can see the bottom of the block, select (

) the floor, and choose Edit>Hide. You should be able to see the underside of the untextured ceiling now:

Choose a likely-looking texture for the ceiling and apply it:

Setting the Start Position

There's one more thing we need to do before exporting -- we need to add a Player object to the level, so that the starting position is specified.

Objects such as players, monsters and items are represented in the Sketchup model by placeholder objects. It doesn't matter what the placeholder looks like, but it's a good idea to use something with mnemonic value. The MarathUp distribution includes a Sketchup file called Objects.skp containing predefined objects representing a few of the available Marathon objects (more will be added in a later version).

Before adding a player, we need to get access to the floor again. Unhide everything, rotate the view back down until you're looking down at a fairly steep angle, and hide the ceiling again. You should be getting fairly good at this sort of thing now, so I won't go into step-by-step details. You're after a view like this:

Open up Objects.skp now. It should look like this:

Here we've got a Player, four kinds of Pfhor fighter, and a clip of pistol ammo. (There are also some other objects in there that we'll come to later.) Select the Player (a blue box should appear around it) and Copy it. Then switch back to your example model window and Paste. The cursor changes to the Move tool , waiting for you to position the pasted-in object. Click somewhere on the floor away from the walls. If all goes well, you should see something like this:

The newly-pasted object is selected and the Move tool

is still active, in case you want to reposition it. In this case it's fine where it is, so we can just deselect it by switching back to the Selection tool

and clicking somewhere on the background.
You may want to rotate the view to a shallower angle to get a better idea of how the player is positioned vertically. His feet should be just touching the floor.

Exporting the Map

Now we're ready to export. Go to the Plugins menu and choose Marathon>Export Map. If all goes well, you should get a confirmation like this:

If you've followed the tutorial steps exactly, there shouldn't be any problem, but it's possible for there to be errors in the model that prevent a Marathon level from being constructed from it. If that happens, you'll get an error message, and you'll need to correct the problem -- more on that later.

If nothing appears to happen at all, it's possible that the Ruby script has crashed. This would indicate a bug in the script, in which case I'd like you to tell me about it. See Troubleshooting for how to get diagnostic information to send me.

Assuming the export is successful, there should now be a file in the same folder as your Sketchup file with the same name except for a .sceA extension. This is a map file that Aleph One should be able to open and play.

Testing the Map

To test your map, you need to set up an Aleph One installation containing appropriate files. Create a new folder and copy the following things into it:

The Aleph One application.
A set of valid Shapes, Images and Sounds files from another working Marathon 2, Marathon Infinity or Aleph One based game. For this example, the ones from Marathon 2 itself should be fine.
The Scripts folder from the Tutorial folder in the MarathUp distribution. This contains a text file called Files that tells Aleph One which map file to use. It's set up assuming the map file is called Example1.sceA; if you've called your map something else, you will need to either rename the map file or open the Files file with a text editor and modify it to suit.
Your map file (Example1.sceA or otherwise).

The folder contents should look like this:

AlephOne.app or AlephOne.exe
Example1.sceA
Images
Scripts

Files

Shapes
Sounds

Now launch Aleph One and hit Begin New Game. You should end up in a room that looks a lot like what you just made in Sketchup. Spin around and take a look at the scenery.

You may find some odd things happening if you try to move around, though. This is because Aleph One can't handle maps consisting of just a single polygon properly. Things will get better when we add some more polygons in Exercise 2.

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