Action0/Objects

Introduction

Defining properties of new objects.

Unlike vehicles or new stations, most new objects have no real equivalent in TTD.

The IDs are therefore free to be chosen and will in fact be allocated automatically by the patch. In action 0, you only specify IDs relative to the set, i.e. the ID of the first object type is 00, the second object type is 01 and so on.

OpenTTD supports 64000 object types per game, and 255 object IDs per grf file.

64000 object IDs per grf file are supported since OpenTTD 14.0.

The property you must set for each object ID is 08 (in addition to defining an action 3 for it). Also, all object IDs must get their classes in the right order, starting from ID 00 onwards.

Properties

Number	Size	Version	Description
08	D	1.1 2.6	Class label, see below
09	W	1.1 2.6	Text ID for class
0A	W	1.1 2.6	Text ID for this object
0B	B	1.1 2.6	Climate availability
0C	B	1.1 2.6	Byte representing size, see below
0D	B	1.1 2.6	Object build cost factor (sets object removal cost factor as well)
0E	D	1.1 2.6	Introduction date, see below
0F	D	1.1 2.6	End of life date, see below
10	W	1.1 2.6	Object flags, see below
11	W	1.1 2.6	Animation information
12	B	1.1 2.6	Animation speed
13	W	1.1 2.6	Animation triggers
14	B	1.1 2.6	Object removal cost factor (set after object build cost factor)
15	W	1.1 2.6	Callback flags, see below
16	B	1.1 2.6	Height of the building
17	B	1.1 2.6	Number of object views
18	B	1.4	Measure for number of objects placed upon map creation

Check Lakie's Graphical Representation of the newObject Specifications

Descriptions

Object class (08)

Class labels are unique identifiers composed of the letters A-Z and/or the numbers 0-9,  analoguous to station class labels.

Their main use is to combine objects into classes and make them available by the top dropdown list in the object construction window.

Unlike for stations, there is no default class for objects. Set authors have to specify their own labels, although it is strongly recommended to follow a general scheme to try to avoid confusion.

Class IDs must be set before any other property.

Object class text ID (09)

The text ID for this class (word value). This textid should be either a TTD textid or a D4xx textid (set via D0xx in action4).

When specifying an object, you don't need to set a class name again if you already did for another one with the same class.

Object text ID (0A)

The text ID for the object for query and selection (word value). Same requirements as for property09.

Object size (0C)

The object size up to 15x15 tiles.

This byte value is divided into two nibbles. The first defines the size in y direction and the second defines the size in x (i.e., stored as YX).

Note that any value lower than 0x11 will be rejected.

Build Cost (0D)

The build cost multiplier. This is multiplied by the number of tiles for evaluation of construction and removal costs of an object.

Introduction date (0E)

Introduction date of an object, in days since the year 0. This takes account of leap years; divisible by 4, but not 100 unless 400. A start date of 1920-01-01 is obtained with a value of 701265 (51 B3 0A 00). In TTDPatch anything before 1920 is considered to be always available, and it should allow for objects to work past 2044, the date is also the very first date you can build the object.

End of life date (0F)

Last year an object can be build, in days since the year 0. Same requirements as above. Also note that it must be a minimum of a year (365 days) after the introduction date or TTDPatch will ignore it.

Object flags (10)

The following flags control object behaviour and are cached for built objects, so changing these flags will have no effect on already constructed objects.

Bit	Value	Version	Meaning
0	1	1.1 2.6	Only Available in the scenario editor
1	2	1.1 2.6	Irremovable
2	4	1.1 2.6	Anything Can Remove (owned land behaviour)
3	8	1.1 2.6	Allow construction of the object on water
4	16	1.1 2.6	Removal cost is actually income (owned land behaviour)
5	32	1.1 2.6	Do not display foundations if on a slope
6	64	1.1 2.6	Object has animation
7	128	1.1 2.6	Only available during game play
8	256	1.1 2.6	Allows 2cc mapping for objects instead of the default 1cc
9	512	1.1 2.6	Disallows construction on land (also has bit 3 behaviour)
10	1024	1.1 2.6	Draws the water under the object
11	2048	1.1	Allow bridge over the object taking the building height into account
12	4096	1.1 2.6	Random bits in the "next animation frame" callback
13	8192	1.4	Scale amount of objects placed on map generation not by map area, but roughly by the length of the coastline

Animation information (11)

The low byte specifies the number of animation frames minus one, so 00 means 1 frame, 01 means 2 frames etc. The maximum number of frames is 256, although you can have some problems if your animation exceeds FD (253) frames. The high byte must be 0 for non-looping animations and 01 for looping animations. Every other value is reserved for future use. In addition, if the whole word contains FFFF, animation is turned off for this object (this is the default value).

Since you can't have properties for individual object tiles, this property applies for every tile of the object. If you don't want to animate some tiles, you should check the current position during callback 159 and return FD if the current tile doesn't need to be animated. If you also need animations of different length per tile, you'll have to use callback 158 for that.

Animation speed (12)

The meaning is the same as for house property 1B, but the lower limit is 0 instead of 2, so the fastest possible animation changes frames every game tick (27ms). The default value is 0.

Animation triggers (13)

This is a bit mask of events that should trigger callback 159, allowing to change the animation state

Bit	Value	Meaning	Happens on	Var 18
0	1	Object is built	all tiles
1	2	Periodic tile loop	single tile
2	4	Synchronised periodic tile loop	all tiles

Currently no trigger provides additional information in var 18.

The synchronised periodic tile loop is called directly after the (unsynchronised) periodic tile loop of the northern tile.

Object removal cost factor (14)

Cost factor for the removal of an object. This must be set after property 0D (object build cost factor) as that overwrites this value.

Callback flags (15)

For objects, the following callbacks can be defined by setting the corresponding bit in property 15:

Bit	Value	Variable 0C value	Callback
0	1	157	Custom slope check
1	2	158	Decide next animation frame
2	4	15A	Decide animation speed
3	8	15B	Decide colour of building
4	16	15C	Show additional text in the build object window
5	32	15D	Allow/disallow autosloping

Building height (16)

Set the height of the building in heightlevels (8 pixels). For example if the structure is 16 pixels high you set this property to 2.

1.1  In OpenTTD this property is used to determine the height of the build object window; the height for the object preview is set to 32 + "value of property 16" * 8. The property is also uses to determine how high a bridge must be if it is allowed by the bit in property 10.

Number of views (17)

Objects may have "views", i.e. different graphical representations, e.g. used to show rotated views of an object. Number of views may be 1, 2, or 4. Default value is 1.

For non-square objects, x and y sizes are swapped for odd views. I.e., giving an object size of 1*2 (x = 1, y = 2), it will be displayed as 1*2 for num = [0,2] (x-direction) but as 2*1 for num = [1,3] (y-direction).

Use object varaction2 var48 to access particular views of an object.