Exits and Pipes

There are a number of ways you can complete a level in World of Goo, but by far the commonest is the pipe. see also Ending Levels without a pipe
However it's not the pipe that actually ends the level, it's a levelexit item, but you'll need both.

At it's simplest...

When the Editor creates a new level it includes a levelexit
Move this to where you want it and click the AutoPipe button on the toolbar, and you're almost done!
You just need to set how many balls are required to complete the level... see [ballsrequired]

If you want a little more than the "simplest"...

Pipes in detail

A pipe item is purely visual, it doesn't actually DO anything to the Goo Balls. A pipe just shows the player where they are aiming for, and becomes animated when the exit is open and Goo Balls are collected.
They have a type attibute which controls the colour of the pipe, but it does not affect what types of Goo Balls can or cannot be collected.

Pipes have child vertexes

The vertex items tell the game where to place the mouth of the pipe, where the bends are and where the pipe ends. You can have as many vertexes (bends) in the pipe as you like. However, pipes can only ever run horizontally or vertically and if there is a bend they MUST turn, if they go straight on (or turn back on themselves) the game crashes. The Editor will help you with this.

The first vertex listed is the mouth, it can be moved freely and should be positioned at (or close to) the centre of the levelexit. You should always position this first. Any other vertexes will "snap" into allowed positions as you drag. [Video that shows all of the above stuff about vertexes]

The levelexit

As mentioned above pipes are just visual items, it's levelexits that do all the real work. They control the opening / closing of the pipe, they suck Goo Balls towards their centre when the exit it open, and they allow balls into the pipe (or not). They also display the small puffs of air sucking towards the centre.
The radius attribute affects two functions of the pipe. It sets the detection distance for opening the pipe, if there is an attached Goo Ball within the radius, then the exit and pipe open. It also sets the suction range, (almost*) all Goo Balls within the radius are sucked towards the centre.
But not all Goo Balls will be collected.
Whether or not a Goo Ball is collected is controlled by two things. Some types of Goo Ball can never be collected (those tagged suckable=false; Pokey, Beauty, BlockHead etc). All other Goo Balls can be collected, and you can use the filter attribute to control which are "allowed" in this level.

If filter is empty or missing, then any "suckable" Goo Ball will be collected. Otherwise filter can be set to allow one (or more) specific types of Goo Ball into the exit. When more than one type of Goo Ball is allowed the types should be comma-seperated common,Ivy for example.

Notes

Custom Pipes

In addition to the 4 "normal" pipes ('Grey','BLACK','BEAUTY' and 'ISH') it is possible to add your own custom pipes.
You could simply override the original graphics with your own, but this would also change the pipes throughout the original levels. So if you want to keep your special pipes "to yourself" and only use them in your levels... here's how.

Choose a name for your pipe

Something descriptive and "unique"... certainly nothing that has been used before. I used LEMON and since it is case-sensitive you are best sticking to UPPERCASE like the original types.

Create the new graphics

You will almost certainly need to create images for the open and closed mouth and the pipe itself, and it will be easiest if you keep the original naming convention for these images

pipe_horiz_{PIPENAME}		pipeCap_closed_{PIPENAME}		pipeCap_{PIPENAME}

You could also create new images for the bends or corners, although for LEMON I just used the original black corner graphics that are used on the Grey,Black and Beauty pipes.

Add the Pipe Resources

If you plan to use this pipe in just 1 or 2 levels, you should add the resources to the level directly. Import the pipe images into your level then change the resource ids to match the list below. WooGLE will then automatically include the pipe resources and graphics in the goomod.

If you plan to make a level pack or chapter which uses the custom pipe many times, you should add the resources to the global properties/resources.xml.bin. However, you will need to add a merge file and all the necessary graphics to the goomod yourself.

id		path
IMAGE_GLOBAL_PIPE_{PIPENAME}		res/images/levelimages/pipe_horiz_{PIPENAME}
IMAGE_GLOBAL_PIPE_BEND_TL_{PIPENAME}		res/images/levelimages/pipe_bend_tl_{PIPENAME}
IMAGE_GLOBAL_PIPE_BEND_BR_{PIPENAME}		res/images/levelimages/pipe_bend_br_{PIPENAME}
IMAGE_GLOBAL_PIPE_BEND_TR_{PIPENAME}		res/images/levelimages/pipe_bend_tr_{PIPENAME}
IMAGE_GLOBAL_PIPE_BEND_BL_{PIPENAME}		res/images/levelimages/pipe_bend_bl_{PIPENAME}
IMAGE_GLOBAL_PIPE_CAP_OPEN_{PIPENAME}		res/images/levelimages/pipeCap_{PIPENAME}
IMAGE_GLOBAL_PIPE_CAP_CLOSED_{PIPENAME}		res/images/levelimages/pipeCap_closed_{PIPENAME}

Notes about image files:
The paths shown above are for example only, you may use any valid image file for any of the pipe resources.
The image files do not have to be in res/images/levelimages, and if this pipe will only be used in one level it would be best if you put the images in the level folder.
You can use the original black bend images by simply omitting the _{PIPENAME} from the paths for the BEND resources.

Set the pipe type

Finally you need to set the pipe's type attribute.
This must exactly match the {PIPENAME} you used in the resource ids.
NB: You can only enter a "custom" name into type in WooGLE v0.74 and above. If you use a "custom" pipe then it will display as bright red in the level view.

If you want a closer look, or a reference for creating your own pipe, you can download my Lemon Pipe Demo below

Attachment	Size
lemonpipe.goomod	15.38 KB

Explored Area

By default the camera is allowed to roam anywhere within the defined [Scenebounds], however if you set the autobounds attribute of the level to true, things get a little more complicated.

The game has the concept of an "explored area".
Put simply this area begins surrounding just the starting area and any initial Goo Ball structure and expands as you build to reveal more and more of the level.
Note: The explored area will not contract if the player dismantles their structure.

However there is a bit more to it than that...

The camera is allowed to move anywhere within the explored area and can show up to 800pixels either side horizontally and 600pixels above or below, although it will not go outside the defined scenebounds.

Note on Wide-Angle Cameras

If the initial zoom of the camera is "small" and the camera would show areas outside the explored area, the game automatically zooms in until only the explored area is visible. Each time the explored area expands the camera zooms out until it reaches its nominal zoom setting.

Fire

You can add particle effects that look like fire easily, see particles, but if you actually want to set Goo Balls on fire, you need a fire object.

Fire objects are circular so have a center and a radius. Any Goo Balls with a non-zero burntime attribute are flammable*, and will catch fire if they enter a fire object.

Note: Thrown balls do not catch fire, unless they bounce off something first.

You can control what the fire looks like using the particles attribute. You can select any local particle effect, although for playability you should choose

• an effect that looks like fire
• an effect that approximately matches the size of the fire object.

* Balls that are flammable

• Fuse
• Ivy
• Bit, Pixel, PixelProduct
• BombMini, BombShaft, BombSticky, ZBomb
• Drained, DrainedIsh
• BeautyProduct (but not BeautyProductEye, or UglyProduct)

Ivy balls are "flammable" in that the same "fire" property is used for "poisoned", just with different particle effects. Therefore it is inadvisable to use Ivy balls on levels containing real fire.

Goos and Strands

What is a Goo Ball?

The answer may seem obvious, but if you're new to editing World of Goo levels then there are some types of Goo Ball you probably won't be familiar with.
Things that you might not know are Goo Balls, but are.

• The Squares and Rectangles in "Graceful Failure"
• Timebugs
• Fixed Anchor Points
• The UndeletePill and the mass of Spam Envelopes in "Deliverance"
• The Applications and Games folders that create the window blocks in "MOM"

All these things are Goo Balls, along with the ones you'll know like "Ivy" and "Fuse". The different types of Goo Balls

Adding Goo Balls (aka BallInstance) to your level

The Goo-lbar allows you add any of the common types of Goo Ball from the original game. You can also add any other type of Goo Ball that came with the game, or a custom one you have made yourself, just add any Goo Ball from the toolbar, then change its type attribute to the type you want.

Goo Balls can be selected and moved with the mouse in the Level View. Square balls (Bone, BlockHead, RectHead etc) can also be rotated using the mouse.
You can Cut, Copy, Paste and Delete the selected Goo Ball using the toolbars, menus or the usual keyboard shortcut. Note: Pasted Goo Balls will appear exactly on top of the Copied one. So you should spread them out afterwards.

Connecting them together

Goo Balls can be connected together using Strands. The easiest way to do this is using the new "Strand Mode"
All you need to do is click on a Goo Ball and drag the rubberband line to another Goo Ball. If a Strand is too long, it be shown in red.
Some types of Goo Ball cannot have Strands (Beauty's, Blocks etc) the editor will prevent you from connecting these types of Goo Ball together.
Strands can be removed by simply selecting them and pressing {Delete} or from the Edit menu / toolbar

Note on deleting Goo Balls
If you delete a Goo Ball which is connected to another then the Strand will remain. Strands with only one (or no) Goo Balls attached will be highlighted in the Level Tree Tab.

discovered or sleeping

Goo Balls have a discovered attribute, this sets whether they begin the level awake or asleep. If this is left blank or set to true then the Goo Ball will begin the level awake. If discovered is set to false the Goo Ball will begin the level asleep.
Hint: By default Goo Balls are added awake. If you want a lot of sleeping Goo Balls, it is easier to add one, set it to be asleep, then Copy and Paste it as many times as you need.

Utility Balls

There is yet another type of Goo Ball; the Utility ball. These balls are used for many different things in the game, some you will have seen (the black support chain in Genetic Sorting Machine). Others you will not because they are invisible, and are used to do something "special" like playing a sound-effect or producing a cloud of other utility balls that each produce a particle effect. More information on Utility Balls

Music and Sound

There are two background sounds that can be played during your level: music and an additional loopsound. Both can be set from buttons on the WooGLE toolbar or from the Resources menu.

What music does should be obvious. loopsound provides additional background sound effects.. like wind, water or squeaky windmills.

You can select any ogg sound file to be either music or loopsound - see below for lists of those used in the original game. If you want to use your own music or sound effects you will need to convert them to Vorbis ogg format... [more information on sound files]

Music files

Sound files

Music by Level Name

Force Fields

There are 2 types of forcefield, linear and radial, these can provide effect like gravity, wind and water.
linearforcefields can simulate a number of very different effects depending on their settings.

Ambient Fields (Gravity)

If a linearforcefield has no size attribute (or it is left blank) then it is an ambient field, and it affects the entire level. Almost all of the original levels have an ambient field providing the gravity.

Local Fields (Wind)

linearforcefields can also be localized by giving them a size and a center. In this case only objects inside the field are affected by it. This is used most commonly to simulate wind or to support the Goo Balls when they are sitting on a cloud.

Water

When the water attribute is set to true, the game displays the water effect within the field in the given color. The top edge of the field is given surface ripples and makes little splashes when objects enter or leave at speed. However beyond these visual differences the field's physics operates in the same way as any other Local field.

radialforcefield

These fields are also used to provide a gravity effect, but on a larger scale. Used in Graphics Processing Unit and Main World View to give the orbiting effect. These fields cannot be ambient, so they must always have a center and a radius specified. The type,antigrav and dampeningfactor attributes work the same as linearforcefields see above

Note on geomonly

This attribute can be applied to linear fields. When set to true the field only affects dynamic geometry objects and not Goo Balls. This can be useful in the construction of mechanisms - [link to...]
Note: geomonly tag was present on all radialforcefields in the original levels, but doesn't have any effect when set to true, so was removed from WooGLE in v0.74

Geometry

In the World of Goo, the geometry objects are what make things solid. Geometry is what the Goo Balls can sit on, walk on, attach to, bounce off etc.

There are several different kinds of geometry object you can include in your level, but no matter how complicated your level is, it's all built out of very simple shapes (rectangles and circles).

Geometry objects can be fixed in space (static) or moveable/moving (dynamic). They can be made of various materials, and can have a whole host of different effects on the balls and other things.

Geometry objects can also have images attached to them. This is unnecessary on static geometry - it is usually simpler to use a separate SceneLayer item for the image. But if you want the geometry to move, and you want the image to move with it, you must add the image to the geometry object.

Geometry IDs

Every geometry object has an id attribute. When you add a geometry object to your level, WoG Editor will automatically assign it a unique id of the form geometry{number}.

You can change these IDs to whatever you like, and the game is quite flexible in that regard. It will allow objects with duplicate IDs and blank IDs without complaint. However, this can cause you endless problems whilst you're editing the level.

WoG Editor will report any problems by refering to an object's ID. If you have many objects with the same (or blank) ID, you won't know which object actually has the problem.

Once you start designing larger levels, with dozens or hundreds of geometry objects, it can be useful to start giving them "meaningful" names: platform1, leftwall, killerwheel or whatever. As long as you keep these names unique, you will be fine.

Basic Shapes

There are only two basic shapes that Geometry objects can be; rectangles and circles. Most of the solid objects in your levels will be built using just these items.

Rectangles		Circles

These shapes can be positioned, resized and rotated using the mouse in the Level View window, or you can enter values directly into the Properties Pane.

Options / Attributes

Static or Dynamic
tag attribute
[Material]
[Applying Images to Geometry]
[Making Geometry less Solid]

Composite

compositegeom objects are very similar to the Basic Shapes objects, with a couple of crucial differences and a few "quirks".

The basics of a compositegeom are most easily explained with a short video.

Whilst you can add as many children as you like to a compositegeom, and build a something fantastically complicated, it is still a single object, and it will move and act as such. Like other geometry objects it can have a material, tags and an image, and the compositegeom passes on these properties to all of its children.

So why is that useful?

The main uses of these objects are:

• Moving Objects which are 'complex' shapes
  The Third Wheel in "Third Wheel" is a compositegeom object, as are the fingers in Genetic Sorting Machine.
• Grouping a number of basic shapes together so that they share certain attributes.
  Most of the platforms in "Alice and Bob" are parts of the same object, and all the walls and ledges in "Grape Vine Virus" are one big compositegeom.

Another crucial difference between compositegeom and other geometry objects is that compositegeom objects do not have a mass attribute. Their mass (and centre of gravity) are calculated from the masses and positions of all their child objects.
NB: This only matters when you are using [Dynamic objects].

Bugs

compositegeom objects also have a few "quirks" (steming from bugs in the game engine):

• Incorrect handling of deadly and mostlydeadly tags with "sticky" Goo Balls - see note in tag attribute
• Incorrect handling of nocontacts attribute with "sticky" Goo Balls - see note in [Making Geometry less Solid]
• Unexpected Displacement of Rotated, Dynamic compositegeom objects - [link TBA]

Dynamic

Dynamic Geometry is any geometry object that is set to static=false or {blank}. Dynamic objects can move or be moved, they will respond to forcefields (including gravity), they will react when Goo Balls or other geometry hits them. In short they behave as if they were real solid objects in your level.

Important Note: All Dynamic objects require a mass

If you set static=false you must enter a value for the mass of the object.

Despite what you might remember less than half the original World of Goo levels contained Dynamic Geometry.
If you're looking for information on how to create any of the following...

• spinning cogs
• wheels that will pop a Beauty Ball
• windmills that kills Goo Balls
• the wobbly head in "Chain"
• the lifting wheels from "Third Wheel"

then you should probably read this instead - Making things Spin!

There are a number of categories of Dynamic Geometry.

Free Standing

These are objects which are not fixed to anything, and are free to move or fall as the physics engine dictates.
Examples of Free Standing Objects

• The head block in "Burning Man"
• The Bomb Carriage in "Upper Shaft"
• All those explodable blocks in "Deliverance"

Free standing objects are the simplest to set up. Once you have set the object to static=false and given it mass.. you're done. Although you'll probably want to apply an image to it, so that the player can see it. see [Applying Images to Geometry]

Hinged

These objects can move, but they are constrained to rotating about a point, a hinge. The hinge can be a fixed point or can be attached to another dynamic object.
Examples of simple objects using fixed position hinges

• The platform in "Server Farm" - View Image
• The liftable bars/gates in "Flying Machine" - View Image

To create an object like this, set it to be static=false and give it a mass, then add a hinge object to the level. Move the hinge into the correct position and set its body1 attribute to the id of the geometry object.
[Full details on hinge and its attributes]

Examples of more complex hinged objects

• The Red Carpet Extend-o-matic machine in "Red Carpet" - View Image
• The machine/robot/thing at the bottom of "Deliverence" - View Image

Notes on Hinged objects

• When two dynamic objects are hinged together, they will not collide with each other.
  However they will still collide with other geometry objects and Goo Balls.
  And if A is hinged with B, and B is also hinged with C.. A and C can still collide. In the case of the Deliverance "robot".. the fingers could collide with the head, because they are not directly connected by a hinge.
• Hinges cannot be attached to compositegeom child objects.
  If you attempt to attach a hinge to a compositegeom child, the connection will be ignored, and the hinge will be in a fixed position. To hinge a compositegeom object you must attach the hinge to the parent object.
• Hinges cannot be attached to Static Geometry
  Again, if you try the connection will be ignored and the hinge will be a fixed position. This will not affect the dynamic object directly, since it was being hinged to a fixed body anyway. However, since the 2 objects are not connected by a hinge, they will collide as normal.
• Bug in the game: Timebugs vs 2 body hinges
  If you have a hinge which connects 2 dynamic bodies, then its position is not correctly reset when a timebug is popped, this can cause some very undesirable effects. Fixed position hinges are fine, but hinges that move get badly messed up.

Lines

Line objects are used to define the edges of the level, as far as the Goo Balls and dynamic geometry are concerned. Lines are the simplest type of geometry object, however if you don't understand how they work, they can cause you all sorts of problems.

Lines have a position (anchor) and a normal direction (normal). Together these tell the game where the line is and what its rotation is. The normal dictates which way the line points and defines the front and a back. It's the front and back which are important, because Goo Balls and dynamic geometry objects can only ever be in front of a line.

In fact, they must be in front of all the lines in a level. You must always have the normal's pointing inwards towards the middle of your level. If they face outwards then Goo Balls are not allowed to be in your level.

If a ball or dynamic geometry is placed the wrong side of a line, the physics simulation will go berserk due to the illegal placement.

Lines have a tag attribute and a material, so they can affect Goo Balls, Structures and Dynamic Geometry in many different ways.

Unlike circles and rectangles, lines can't be placed into a compositegeom - not that this would make sense anyway.

Static

A Geometry object can be made fixed and unmovable by setting its static attribute to true.
Static objects are used for Walls, Cliffs, Platforms and the other things in your level that will never move. The vast majority of the geometry in your level will usually be static, so WoG Editor sets static=true on geometry objects when you add them.

The static attribute only affects the "fixed" nature of the Geometry object, it can still be assigned a [material] and tags.
You can also apply images to static geometry, however you are normally better using a separate image object. The only time that static geometry requires an image is when it can be destroyed - see [Making Geometry less Solid]

Note on Building Walls and Cliffs

There is a bug (more a "weakness") in the World of Goo game engine which allows fast moving Goo Balls to pass through thin walls. This has been used to great advantage by many players in order to beat levels faster or better.

However it can also be annoying and problematic if a level is designed "poorly" and Goo Balls can accidentally pass through thin walls and become stuck or die. The best way to avoid this problem is to make your geometry as big and solid as possible, rather than building thin walls around the edges of the images. Overlapping regions are fine, in fact they are encouraged, since Goo Balls can get stuck in small gaps between geometry that almost touches.

Images

Image objects, known as SceneLayers in World of Goo and WoG Editor, are how you get graphics into your level. It is important to realise that images are not solid. Just because you add a picture of a cliff to your level, this doesn't mean the Goo Balls will sit on it. You need geometry objects to make things solid.

SceneLayers let you build up the visuals in a level, from the background image to what the walls and cliffs look like, and they let you add foreground objects, like bushes, which come between the player and the Goo Balls.

You cannot import image files directly onto a SceneLayer object, the image file must first be added to the resource list and given a unique id. You can then select this id from a list in the image attribute of the SceneLayer.

Once you have assigned an image the SceneLayer can be moved, rotated and resized using the mouse in the Level view, or by changing the center, rotation and scale attributes.

Images also have depth

This allows you to control which images appear in front or behind other images, the geometry and the Goo Balls. depth can be positive or negative (positive values are in front of the Goo Balls, negative values are behind), and can be a fractional number (1.234).

It also controls the "distance" to the image. Over a limited range (where depth is between -2 to +2) the only apparent effect is which things are in front and which are behind. On a larger scale a parallax scrolling effect can be seen. Objects with large negative depth (-1000 say) will appear to move more slowly around the screen as you scroll, simulating being further away. Objects with positive depth (+200) will be in the foreground, will move faster as you scroll and will appear between the player and the Goo Balls. [Embed Video]

Other useful SceneLayer attributes

alpha allows you to control the overall transparency of the image.

colorize allows you to change the color of an image.
The image will become tinted by the RGB color you enter [Technical Details Here]
A value of 255,255,255 will display the image unchanged, and 0,0,0 will display a completely black image.

tilex and tiley repeat the image across the whole level.
Used in the original World of Goo Corporation levels for the "infinite" sky and ground. Note:tilex and tiley should not be used with rotated images, see this example showing why not.

SceneLayers can also rotate/spin, see Making things spin, or can be animated. However, whilst this may make the images move, they will still not interact with the Goo Balls or Geometry objects. If you want to create a moving object which can affect things, see [Applying Images to Geometry]

Full details of all the SceneLayer attributes and their functions [Here]

Notes on depth

• Images representing walls, cliffs should be as close to depth=0 as possible.
  This applies to all SceneLayers showing the image for any solid object created using geometry. If these images have a large positive or negative depth, then they will move relative to the geometry, and Goo Balls may appear to bounce off thin air, or fall through a cliff, rather than off the edge. This is because the balls and geometry themselves are at depth 0.
• The absolute maximum foreground depth is +700
  This is where the camera is. Beyond this, the game considers the image to be behind the camera, but will still attempt to display the image. This causes some rather odd and disorientating effects.
  For foreground objects such as bushes, trees and rafters etc. depths in the range +100 - +300 are best.

Animations

SceneLayer objects can be animated by setting their anim attribute. There are many different animations available to choose from, however only a few of these will be of any real use in a level.

"Useful" Animations Library

Animation Speed animspeed

Most animations run quite quickly at their default speed (animspeed=1), so you will usually need to slow them down by setting the this to a number less than 1. You can use negative values to make the animation run in reverse.

In particular, rot_1rps is an animation with precisely 1 rotation per second. To make something rotate once every 10 seconds, set animspeed=0.1.

Animation "Delay" animdelay

This appears to be named incorrectly, as it actually appears to do animation advance. In the video below, the object with animdelay=0.1 is ahead of the object with animdelay=0.

You may also notice that animdelay=0 and animdelay=1 give identical results.. in fact animdelay={x} seems to be the same as animdelay={x+1} (presumably the animdelay is a specified as a fraction of the animation duration).

Note on Animations and Scale

SceneLayer items can have both a scaling factor and an animation set.
However the game seems only to support uniform (x=y) scaling in conjuction with animations, and if presented with non-uniform scaling, will use the larger scaling factor on both axes.

So scale=2,2 or 0.5,0.5 appear as expected, but scale=0.5,2 will appear in the game as if you entered scale=2,2

Importing

Before you can use an image in WoG Editor you must import it into the Resource List. To do this click the Import Images button and select the file (or files) you want to import in the standard file dialog.
Each file that you select will be given a unique id and added to the resources list, if it's not there already. The id will be automatically generated and will be something like IMAGE_{FOLDERNAME}_{FILENAME}
When you edit the image property of any object, a list of the ids of all the image resources will be displayed.

Image File Format

World of Goo uses png files for all its graphics. It will accept any "flavour" of png file (paletted, grey-scale or 16m colour) and supports both alpha-channel and single-colour transparency.

Importing "external" images

All the image files that World of Goo uses must be located within (or below) {Game_Folder}/res/ If you import files from anywhere within this folder then WoG Editor will just add the filename and id into the resource list.
However, you can import images from anywhere on your system.
If you import files from outside the res folder WoG Editor will take a copy of each file and place it in the [Level Folder], and add the copies into the resources list.

Note on Images for Mac

On Mac, World of Goo uses graphic files in a "non-standard" and substantially different format Details here. GooTool will convert standard png images to this format when it installs a level.
(TODO: State whether GooTool will also convert jpg renamed as png correctly on Mac)

Labels

labels can be used to add text to your level. In the original levels they were only used in Alice and Bob and MOM.

labels have a position atrribute called center, which is slightly misleading since it is not always the centre of the text. The final positioning of the text is also affected by the align attribute.

In the image the tip of the arrow is at the center coordinates.

labels have a rotation and a scale factor which can enlarge or reduce the text.

They also have a depth which operates in the normal way, but this can be overriden using the overlay attribute. If overlay is set to true, the text will be display on top of (in front of) everything else, regardless of the depth setting of the label, or the depths of the other elements in the scene.

text

The actual text for the label is held in a [Text Resource], so that it can be multi-lingual. The id of the text resource is selected using the text attribute of the label.

font

There are a number of fonts you can choose from, however not all the fonts can display the full character set.

Particles

particles items generally provide the background effects for a level like falling leaves, or snow or mist, but they are also used to provide effects such as fire, the signpost !'s and the musical notes created by the whistle.

There are 2 types of particle effect

• Ambient which cover the entire level
• Point-Source which eminate from a particular location

particles items have a position pos which only affects the Point-Source effects, and a depth attribute which allows you to control whether the effect appears in the foreground or the background.

The pretick attribute allows the particle effect to be virtually "run" for a time before the level begins. This time allows effects to "get going" or cover the level before it is displayed to the player. It was used very rarely in the original levels. The value is in milliseconds (1000 = 1second) and 1 second seems more than adequate for most cases.

Point-Source (non-ambient) Particles Library

Any of these effects could be used on a fire or signpost object, or as a particles item.

 
Ambient Particles Library

Any of these effects can be used on a particles item.

Guide: Spinning

There are several ways you can make something spin. The correct to do it depends on exactly what you want it to do.

If you just want a spinning background/foreground image

Use this method if you want a spinning image that looks pretty but doesn't affect the Goo Balls, like the small windmills in Blustery Day, or the black cogs in Upper Shaft.

Add a SceneLayer item, apply the image then set:

• anim = rot_1rps
• animspeed = 0.1 for example

In the above example, the image will rotate at 0.1 rotations per second, and thus complete its rotation once every ten seconds.

If you want a spinning cog or gear

If you want something to spin and also kill balls or pop a Beauty ball, like the main windmill in Blustery Day or the "buster" cogs, you are best doing it with two items:

• Add a SceneLayer exactly the same as the above. (this gives you the spinning image)
• Add a circle that's a similar size as the image and move it to the same place and set:
  • static = true
  • tag = {whatever} deadly or ballbuster - see tag attribute

If you want something that balls can grab hold of, or get hit by

Something that interacts with the balls and has physics effects, like the wobbly head in Chain or the wheels in Third Wheel, is achieved as follows:

• Add a Geometry object (Rectangle, Circle or Composite).
• Move it into place, set its image property and position the image.
• Set the object to be static=false and give it some mass - More information on Dynamic Geometry.
• Add a hinge and set body1={id of geometry object}.
• Move the hinge the centre of the object (or the point you want to it to spin around).

If you're happy with something that is moveable but doesn't rotate on its own, like the wobbly head in Chain, then you're done.

If you want it to spin on its own or lift balls, then on the geometry object set
rotspeed = 0.1.

Note about the mass of the object

In this last case, the mass you give to the object affects the power of the motor spinning it. If you set the hinge dead centre in the object it will spin fine regardless of its mass. But if you put the hinge off center, you will find that the motor may struggle to lift the object up one side, but it will drop down quickly on the other.

Also, if you have a "low" mass (like 10), as soon as a ball attaches, the motor will struggle to lift it. If you have a "high" mass (like 10,000), the wheel will grind on regardless and will lift many balls without slowing down at all.

If I can make it spin by just setting the rotspeed, what are motors for?

Well it's a good question. In fact there is only one proper motor object in the whole of the original game - on the robot's head in You Have to Explode The Head.

It seems that even 2D Boy found motors problematic / annoying / mostly pointless, and that using rotspeed and automatically setting the motor's power based on the mass of the object (discussed above) was far easier in most cases, than actually using a separate motor item.

The only time you really need a motor is if you want something that spins weakly but is also heavy, like the Robot's head.

You can't use rotspeed because that would automatically use a strong motor for a heavy object, so this is the only time you really need to use them.

Note: Since motors don't have a size or a position or anything else we could meaningfully draw, they don't show up in the Level View, so you must add and select them in the scene tab.

MapWorldView

Also known as the Main menu, if you are considering a re-design or a “mod” to the MapWorldView level, you will need to make sure that you follow certain rules and include all the items which the game exe will attempt to access and manipulate.

It is recommended, if you are distributing a goomod, you merge your changes into the MapWorldView rather than compiling a new one, so that your mod will interact nicely with other mods that affect this screen.

Requirements

All the following items are required in the MapWorldView level. If any are missing the game will crash, usually right at the start.

buttongroup id="mainbuttongroup" (must contain at least 1 button)
button id="island1"
button id="island2"
button id="island3"
button id="island4"
button id="island5"
button id="island6" (Always invisible, can't be used but must be there)
button id="wogcorp_intact"
button id="wogcorp_3d"
button id="wogcorp_destroyed"

buttongroup id="boringmenugroup" (must contain at least 1 button)
button id="quit" onclick="quit"
button id="changename" onclick="selectprofile"
button id ="credits" onclick="credits"

label id="newballs" text="LABEL_PLUS_X"
SceneLayer id="newmail"

Customizing

So long as the above items are all present, you can modify the MapWorldView layout / level however you wish.

Commands and Actions

Action: island{Number}, selectprofile, credits, quit , wogcorp
Display: island{Number}showtext, islandhidetext
wogcorpshowtext, wogcorpdshowtext, showtooltip, hidetooltip
For more details see [ Commands and Actions ]

WoG Corp

The World of Goo Corporation consists of 3 separate levels; wogc , wogc3d & wogcd
We all know and understand the differences, and in the original game which one is available and when. However the rules the game applies to activate and switch between the different versions could be used in different ways.

The buttons in MapWorldView

The 3 wogcorp buttons are displayed (or not) using the following rules.

wogcorp_intact
Visible if island4 is NOT enabled and island5 is NOT enabled and WoG Corp is not destroyed. Also it is disabled until WoG Corp is unlocked

wogcorp_3d
Visible if island4 is open and island5 is not open and WoG Corp is not destroyed

wogcorp_destroyed
Visible if WoG Corp is destroyed.

Which level is played

The actual level that will be played when the wogcorp command is executed, matches the button which is visible.

The hole in the logic

It may not be obvious from the above, but there can be a gap in the wogcorp sequence.
If chapter 5 is enabled but WoG Corp is not destroyed… none of the buttons are visible.
In this case if you have an additional button which can access WoG Corp, then it will play the original "intact" level.

It is important to note that.. island4 need not be the fourth chapter played, nor island5 the fifth. So WoG Corp could change to "3d mode" immediately, or once the 1st chapter is completed, and could remain in that mode for anywhere from just 1 level, to the remainder of the game… since there is no requirement that WoG Corp is ever destroyed. Whilst changing the order in which the wogcorp levels become available is not possible, you can move through the sequence in different ways.

The Full Sequence

Disabled -> Intact -> 3d -> Invisible (but plays intact) -> Destroyed

By controlling when, and if, WoG Corp is unlocked and destroyed and when island4 becomes available, you can effectively skip various stages.
If WoG Corp is never unlocked, it is inaccessible until island4 is open, then the 3d mode is available, essential you have skipped the "intact" phase.
If WoG Corp is destroyed before island4 is open, you skip the 3d mode entirely.

[More Information about the WoG Corp Levels themselves]

Island1

Guidelines and Requirements for redesign of Island1

Island1 is special, mainly because this is the island into which GooTool places custom levels. If you plan to do a large mod, or multi-chapter level pack, or "WoG2" that will require you to redesign / reuse island1 then you should read and obey the following.

Advanced - Not for the faint hearted or the easily confused

The Rules

You may use compile XML versions of island1.resrc and island1.level

Trap #1

The Fakey Pipe and the Spikey Bar

The inspiration for this trap, came from a prototype level made by momo1526 which had 2 pipes and 2 levelexit's. It didn't work how he wanted it, but it gave me an idea.

Before you read on...
To understand how this trap works.. you should read [Wog Editor Reference : Multiple Exits and Pipes (Advanced)]

The Trap!

The mechanics of the trap are quite simple, although a bit fiddly to get just right.
View Trap Setup
The Spikey Bar is supported by the tiny rectangle (Latch) just below it.
The Latch is part of a compgeom object which also contains the Anchor_Support block... and there's an AnchorStickyInvisible Goo sitting on that.

The compgeom object is non-static and hinged. In this case I put the center point and the hinge in the same place, so that I could see how things would move by rotating the compgeom object in WoG Editor.

But that's it!

View Trap Triggered
When the lower exit is triggered, the Sucker (upper exit) pulls the Anchor Goo towards the center, the compgeom rotates, pulls the latch out from under the Spikey Bar.. and "Gotcha!"

Note: Normally the lower exit (the "Out of Order" pipe) would also collect Goos.
Because I didn't want that to happen in this level... I set the exit Filter to collect GooProduct only, so Ivys, Fuses and Commons will not go in. This means that NO Goo's can be collected in this level...ever!
Which is why I added the "targetheight" to the level, so there IS a way to finish.

I had to be a little careful about what happened after the trap was triggered, and if the exit closed and the sucking stopped.
I didn't want the latch block swinging back to its original position and getting in the way. So I adjusted the mass of the Anchor Support and the position of the hinge, to ensure that once it was triggered it would remain in the triggered position.

Note:
In v0.3 I removed the fire object that was covering the "workings" and put a big pipe graphic over it instead. I also put some geometry around the pipe, so the player wouldn't get caught on the top block, and also to make it easier to build up to the second pipe.
Also I set strandgeom = true (level root) so that you can't build through this new pipe, and strands don't try to attach to the AnchorStickyInvisible

Trap #2

The Pressplate and the Block Thrower

In Trap #1 we used gravity to do our dirty work. Once the latch was released, the Spikey bar just fell on its own.
Here I didn't want the killing object to just fall... I wanted it to be "Spring-Loaded" and fly sideways... and for that we use the "geomonly" Linear Forcefields I mentioned earlier.

It's a Trap!

Again the mechanism here is quite simple, but took a bit a tweaking to get right.
View Trap Setup I have reduced the size of forces in the image, for clarity

The killer block starts inside Forcefield #1, and is held in place by the latch.
The killer block is just a normal rectangle, with an image and tagged as deadly.
Note: In the final level the wall graphic is set to depth=1 so that it hides the block, I changed it here so you could see it.

The latch and the pressplate are parts of the same compgeom object, so that they move together, and the compogeom is hinged. The part of the floor image which moves, is applied to this compgeom object, and I cut out that bit from the "background".

Even though the pressplate is bigger than the latch, the latch is actually much heavier. This is needed to ensure that the latch stays in place, even through the killer block is pushing on it, and to stop the pressplate just falling on its own and releasing the block without the player touching it.
The Endstop holds the pressplate in place, without it the latch is heavy enough to lift the pressplate out of the floor.

I balanced it so that the whole trap is "lightly weighted".. so that even a single Goo would set it off.

View Trap Release
Goo steps on..the pressplate drops, the compgeom rotates and the latch lifts upwards.

Forcefield #1 pushes the block to the right and into Forcefield #2.. which really WANGS it.
You'll notice that ForceField #2 is in the shaft... but it's set to "geomonly=true" so won't affect the goos if they go into it.
Both fields have an upward component to lift the block a bit, and get the firing angle just right.

Notes:
Originally I had one large force field, but I found that it also pushed on the latch.. and could trigger the trap on it's own. So I split the field into 2, and left a gap where the latch is.

Materials:
When the killer block hits the far wall it's going fast. I found using the default material "rock".. made it bounce off to much. The killer block is now "fruit" and the back wall is "swamp". This really deadens the bounce nicely, so even though the block is going fast, it only bounces just enough to land on the pressplate.

In v0.3 I put the Endstop at an angle and changed its material to "ice", because sometimes the killer block would get caught on it. Now the block almost always slides off and kills any remaining Goos...

Trap #3

Blocks Crossing!

This one's more of an obstacle than a "trap" since it's not triggered by anything and it's active and running right from the start.

The "trick" is, how to get a block to move across the shaft, and then go back to where it started and go across again.
A couple of early ideas...
Something like "PONG", where the block goes across one way, then comes back.
Something like a machine gun, with a load of blocks on one side, that drop into the "barrel" and get fired across one after the other. I think this would have worked, but you have a finite amount of "ammo", so if the player takes ages to get there, you'll have run out by the time they do.
(Editor's comment: Maybe that would have worked, if you route the blocks around the level, like the Goo Balls in "Alice and Bob and the Third Party" [AB3])

Make it Spin!

The "neat" answer: Have just one block, and make it spin in a very large circle.
So it goes across the shaft, then moves round (outside the game area) and back where it started and then goes across again.

Despite the fact that this should be simple to make, it was in fact rather annoying. The problem seems to be.. WoG's physics engine doesn't handle rotating, unbalanced objects very well.

Original Setup

Just a single rectangle and a hinge a LONG way above it, and set it to rotate, so the rectangle moves in a big circle. But it was juddery and the rectangle kept moving away from the hinge and catching on other geometry and getting stuck.

v0.2

View Setup I did say the hinge was a LONG way above it.

The new setup has a compgoem object which has 2 rectangles in it (block #1 and #2) These are a long way apart (about 7500 px) and there's a hinge in the middle.
The important thing is that its nicely balanced, and spins great!

The complication with doing it this way, is you can only have 1 image on any compgeom object, so I had to make a tall picture with a little block at the top and one at the bottom.

v0.4

Having written this guide, I decided that it would be nice to show that these "mechanisms" could also be used to help you, rather than just killing Goo Balls.
So I added a new "feature" to the level, the "Do Not Pull" handle.
The idea was simple; add a lever that can be pulled to stop the blocks. Doing it proved less simple.
View Setup Image
The problem was I wanted a moving lever that would push a "killer" block (tagged geomkiller) into the path of the fast moving blocks, and destroy them. However, because the lever is also a dynamic object the "killer" block killed the lever as well. The key was [DIY compositegeom] so that the pushed block and killer block move as a single object, but can have different tags. A similar idea was used in a few of the original levels, Red Carpet for one, but for different reasons.
View Image

The lever is pulled, this pushes the "pushed and killer" blocks into the support field, which keeps them in position, and the next time one of the fast moving block comes around.. the whole "spinner" object is destroyed.
The killer block is also tagged deadly so kills the UtilNuker Goo, which makes the "siren,shut down, hiss" noise.
The "Damping Field" is there to stop the "Do Not Pull" sign from swinging really wildly when the lever is pulled. It is a normal linearforcefield, but it applies no force and just has a dampeningfactor

Notes

I found another "bug" in WoG..
The nogeomcollisions attribute doesn't work when applied non-static compgeom objects, but it's fine on static ones.

So instead.... View Solution
I split the walls on both sides, and added nogeomcollisions rectangle over each pipe mouth.
This stops Goo Balls going into, or getting stuck on, the mouth of the pipe, but it lets the blocks through to kill them just fine

Trap #4

Watch out for the....!

Just when you thought you were in the clear... a blooming great spikey wheel lands on you!

This trap is one of the most complicated and was one of the hardest to set up. Although I think there's a simpler way to do it.. which I might put in a later version of the level.

But for now....
View Trap Setup
There where several issues to consider when I was designing this trap ...
I want it to be triggered as soon as a Goo (balloon probably) comes out of the shaft
I want it to trigger no matter where (left - right) the Goo comes out
I don't want there to be any visible effect on the Goo when the trap is triggered

To cover these 3 things, the Trigger Bar rectangle seemed a good solution.
It's light (mass=1) so it doesn't affect the Goos, it's long and covers the whole shaft, and without an image it's invisible.

The problem is.. because it's so light, it can't do much... and because the Goo won't be going very fast, it doesn't have enough momentum to make very much happen.

View Trap Release (Part 1)

That's where the Thrower Field comes in. It's geomonly again, so doesn't work on the Goos, but it's also a "force" field, rather than a "gravity" field, so as soon as the trigger bar moves up into it, it gets chucked nice and fast, which is enough to make something happen.

View Trap Release (Part 2)

I wanted the Wheel to come from above, so the Pusher bar had to be nice and long and hinged above its center so it just hangs still to begin with.

The Ramp and Hurryup Field are just to guide the wheel and give it a bigger push... otherwise the goos have got up and out before the wheel arrives.

The final touch to this trap is the Quaker Goo (UtilEarthquake)
I got this idea from Product Launcher too...

The Quaker Goo is invisible and doesn't interact with anything and the player can't do anything with it...
What it does do... ALL it does in fact... is make the Earthquake sound when it dies.
The Pusher Bar is tagged as deadly.. so as soon as it moves the Goo dies and the rumbling sound begins... and moments later... Gotcha!

Trap #5

What now!?

Well first... here's a video....
It shows all 4 traps in action, using Visual Debug Mode.
So you can see all the hidden stuff, and all the important geometry is nicely highlighted.

My aim in designing Gotcha! was not to trick you, trap you and kill a lot of unsuspecting Goos....
although I'll admit it was fun...

I know some of you are already thinking about designing similar levels.. or levels that do similar things...and I look forward to playing them... but consider this....

My aim was to show that you can use the physics stuff in World of Goo to create some quite complex "mechanisms".
OK I used them for traps, but that's not the only thing they could be used for.
I can think of plenty of situations where very similar setups could be used to HELP the Goos not just to HURT them.
(See the "Do Not Pull" lever in Trap #3)

They can now open doors, without needing a Bomb to blow them up. They can pull levels and push buttons that actually DO something. A group of goos in one area could complete a small task and open a trap door for other goos in another area.

In short, I believe this is the start of something wonderful... we can now set proper "problems" for the Goos solve...
the possiblities ARE endless.

Have fun!
DaB