Blender BLB Exporter

A Blender add-on written in Python 3 for exporting Blockland bricks (.BLB files) directly from Blender 2.67 and newer without the need for intermediary formats or external programs. It works on the principle of "what you see is what you get", the brick will look exactly the same in-game as it does in the 3D viewport^*.

The add-on does not support importing .BLB files yet.

Table of Contents

1. Features
   1. Planned Features
2. Installation
   1. Updating
3. Terminology
4. Brick Scale
5. Definition Tokens
   1. Mesh Definition Tokens
      1. Defining Quad Sections & Coverage
      2. Defining Colors
         1. RGBA Color Format
6. Definition Objects
   1. Defining Collision
   2. Defining Brick Grid
7. Brick Textures
8. UV Mapping
9. Rounded Values
10. Export Properties
    1. Blender Properties
       1. Bricks to Export
       2. Brick Name from (Single Export)
       3. Export Only (Single Export)
       4. Brick Names from (Multiple Export)
       5. Bricks Defined by (Multiple Export)
       6. Export Bricks in (Multiple Export)
       7. Forward Axis
       8. Scale
       9. Apply Modifiers
       10. Custom Definition Tokens
    2. BLB Properties
       1. Custom Collision
       2. Fallback Collision
       3. Calculate Coverage
       4. Automatic Quad Sorting
       5. Use Material Colors
       6. Use Vertex Colors
       7. Parse Object Colors
       8. Calculate UVs
       9. Square Side UVs
       10. Store UVs
       11. Round Normals
       12. Precision
    3. File Properties
       1. Pretty Print
       2. Write Log
       3. Only on Warnings
       4. Terse Mode
11. Troubleshooting
    1. Automatically calculated UV coordinates for brick textures are distorted
    2. Automatically calculated UV coordinates for brick textures are rotated incorrectly
    3. The TOP brick texture has incorrect rotation in Blender
12. Warning & Error Log Messages
    1. Warnings
    2. Errors
       1. Fatal Errors
       2. Non-Fatal Errors
13. Contributors

Features

The exporter supports all BLB features.

• Brick size
  • Automatic calculation or manually defined
• Brick grid
  • Automatic calculation (full brick only) or manually defined
• Coverage
  • Manually define hiding own and adjacent brick quads
  • Automatic area calculation for arbitrary brick grid shapes
  • Automatic and/or manual quad sorting
• Collision boxes
  • Automatic calculation (full brick only) or manually defined
• Textures
  • Automatic (side texture only) or manual brick texture definition
• Quads
  • Triangles are automatically converted to quads
  • N-gons are ignored
• UV coordinates
  • Manually define UV coordinates
  • Automatic UV calculation for all brick textures
• Colors
  • Multiple ways to define colors: materials, object names, vertex paint
  • Per-vertex coloring
  • Transparency
  • Additive and subtractive colors
• Flat and smooth shading
• Save and load export settings
• Export multiple bricks from the same file
• Vertices are all relative to the defined or calculated brick bounds
  • Object centers (orange dot) are irrelevant: calculations are performed using vertex world coordinates
  • Object locations relative to the origin of the world are irrelevant: the calculated center of the brick bounds acts as the new world origin
  • Object locations relative to the Blender grid are irrelevant: the brick bounds define the brick grid origin (however it is highly recommended to align the brick bounds object with the Blender grid for ease of use)
  • This allows you to easily create multiple bricks in the same file in any location in the 3D space and the bricks still export correctly as expected
  • Arbitrary brick grid rotation, however, is not supported
• Selective object export: selection, visible layers, entire scene
• Change brick rotation during export: does not affect objects in the .BLEND file
• Change brick scale during export: does not affect objects in the .BLEND file
• Apply modifiers (e.g. edge split) during export: does not affect objects in the .BLEND file
• Terse file writing: exclude optional lines from the BLB file
• Pretty .BLB files: extraneous zeros are not written at the end of floating point values and if possible, they are written as integers
• Logging with descriptive error and warning messages to help you correct problems with the brick
• Customizable floating point accuracy
• Exporting DTS collision is not yet supported.

Planned Features

These features may or may not be implemented at some unspecified time in the future. Listed below approximately in the order they are planned to be implemented in.

1. Exporting DTS collision using Nick Smith's io_scene_dts Blender add-on.
2. Importing .BLB files.
3. Automatic rendering of the brick preview icon.
4. Export-time brick rotation on the Z-axis.

Installation

1. Download the add-on using one of them methods below:
   1. The cutting edge: download the latest version of the develop branch or go to the develop branch page and press Clone or download > Download ZIP.
      • The develop branch contains the newest features still under active development. Some functionality may be broken or only half-implemented.
   2. The latest version: download the latest version of the master branch or go to the front page of the repository and press Clone or download > Download ZIP.
   3. A specific version: go to the releases page and follow the instructions on the specific release.
2. Open Blender and go to File > User Preferences > Add-ons.
3. Press the Install from File... button at the bottom of the dialog and find the downloaded .ZIP file.
4. Press Install from File... again.
5. Enable the add-on in the add-ons list and press Save User Settings to keep the add-on enabled the next time you start Blender.
6. The export option is under File > Export > Blockland Brick (.blb).

Updating

1. Open Blender and go to File > User Preferences > Add-ons.
2. Quickly find the add-on by typing blb into the search field.
3. Expand the add-on by clicking the white triangle on the left, press the Remove button, and confirm the removal.
4. Follow the installation instructions above.

Terminology

A list of more or less technical terms used in this document. The definitions are in the context of Blockland, Blender, and this exporter and may vary from their mathematical definitions.

Axis-Aligned Plane

A plane whose vertices have the same coordinate on exactly one coordinate axis. When this two-dimensional plane is viewed from either of the other two coordinate axes it disappears from view.

Axis-Aligned Bounding Box / Axis-Aligned Minimum Bounding Box

A cuboid that completely encompasses all vertices of one or more mesh objects. The faces of this cuboid are parallel with the coordinate axes.

Axis-Aligned Cuboid

A cuboid whose faces are parallel with the coordinate axes.

Brick Grid

1. The three-dimensional space of the game divided into 1x1x1 brick plates
2. The blocks of u, x, -, and other characters near the top of the .BLB file that define the brick's placement rules. See Defining Brick Grid.

Brick

1. A collection of meshes that acts as a single object in Blockland and all the non-visual data it contains such as collision information.
2. The BLB file itself.
3. The Blender objects that when exported produce a BLB file.

Coverage (System)

1. The Blockland coverage system describes how to hide faces on a brick and any adjacent bricks.
2. The six pairs of integers near the top of a BLB file.

Cuboid

More specifically a right cuboid in the context of Blockland bricks. A convex polyhedron with 6 faces that are all at right angles to each other. I.e. a regular cube or a cube that is elongated on one axis.

Definition Object

An object that has a specific definition token in its name. These objects cannot be seen in-game. They exist to tell the exporter how to create the brick. There are three different definition objects:

• a bounds definition object,
• a collision definition object,
• and a brick grid definition object.

Definition Token

A special token in an object's name that tells the exporter additional information about that object or the entire brick.

Face

A visible surface that is rendered in game and in the Blender viewport. The surface must be bound by or created by at least three vertices (making it a tri) or in deed any number of vertices (also called an n-gon).

❗ Blockland bricks only support faces made from exactly four vertices: quads.

Mesh

The vertices, edges, and faces that make up a 3D model.

Mesh Object

A Blender object that contains vertices, edges, and faces. Commonly just referred to as an object.

Model

One or more objects that make up a brick.

N-gon

Technically any polygon but in this document used to refer to a single face formed from more than four vertices. N-gons are not necessarily planes.

❗ These are not supported by the exporter or Blockland: the faces will be ignored.

Object

Usually a mesh object. Technically refers to all the meshes, cameras, lights, empties, and everything else you see in the 3D viewport. Blender objects contain data about vertices, materials, groups, object names, and more.

Plane

A flat two-dimensional surface in 3D space. A particular type of face.

Quad

A face with four vertices. Quads are not necessarily planes.

String

A sequence of letters. Usually a word.

Token

A string surrounded with a whitespace character on one or both sides.

Tri

A face with three vertices. Triangles are always planes.

❗ These are not supported by Blockland bricks and they are converted to quads automatically.

Visible Object

Any mesh object that is not a definition object. Visible objects are rendered and are seen in-game as a brick.

Volume

A section of 3D space, usually cuboidal in shape in the context of this exporter.

Whitespace (Character)

In Blender, commonly a space or a tab character.

Brick Scale

This add-on defines a 1x1x1 Blockland brick to be exactly 1.0 1.0 1.2 Blender units on the X, Y, and Z axes. Likewise a 1x1f Blockland plate is defined to be exactly 1.0 1.0 0.4 Blender units. However, the final scale of the exported brick can be changed with the Scale property. For example setting the Scale property to 150% means that during the exporting process, the objects are scaled by 1.5. This is particularly useful when exporting 3D models created for another BLB exporter/converter that has defined the size of a 1x1f plate to be different from this exporter.

Definition Tokens

Definition tokens are special strings added to the names of objects, materials, vertex color layers, and other Blender data objects that have a name. A name field may contain other text in addition to definition tokens as long as the tokens themselves are separated from other tokens and text by one whitespace character such as a space. The definition tokens may be changed from the defaults by selecting Custom Definition Tokens in the export dialog.

💡 Blender adds a running index (e.g. .003) to the end of duplicate object, material, etc. names. This is handled correctly, you need not worry about it. The logic for removing the index simply checks if . is the fourth last character in the name and simply removes it an everything after it.

❗ Each definition token may only appear once in a name field.

Below is a full list of all default definition tokens with a brief description. For more information on what each of them do, see the specific section of the readme that relates to that token. Note that not all definition tokens change the object into a definition object.

Default Token	Category	Usable In	Is a Definition Object	Meaning
bounds	Definition objects	Object name	Yes	This is a bounds definition object.
collision	Definition objects	Object name	Yes	This is a collision definition object.
gridb	Definition objects	Object name	Yes	Write brick grid b symbol in this volume.
gridd	Definition objects	Object name	Yes	Write brick grid d symbol in this volume.
gridu	Definition objects	Object name	Yes	Write brick grid u symbol in this volume.
grid-	Definition objects	Object name	Yes	Write brick grid - symbol in this volume.
gridx	Definition objects	Object name	Yes	Write brick grid x symbol in this volume.
qt	Quad sorting	Object name	No	Sort these faces in the top section.
qb	Quad sorting	Object name	No	Sort these faces in the bottom section.
qn	Quad sorting	Object name	No	Sort these faces in the north section.
qe	Quad sorting	Object name	No	Sort these faces in the east section.
qs	Quad sorting	Object name	No	Sort these faces in the south section.
qw	Quad sorting	Object name	No	Sort these faces in the west section.
qo	Quad sorting	Object name	No	Sort these faces in the omni section.
c	Colors	Object name	No	The next four numbers define the color for these faces.
blank	Colors	Material name	No	Do not write a color for faces using this material: use the in-game spray can color as is.
cadd	Colors	Material name, vertex color layer name	No	Add the material/vertex color of these faces to the in-game spray can color.
csub	Colors	Material name, vertex color layer name	No	Subtract the material/vertex color of these faces from the in-game spray can color.

Mesh Definition Tokens

Mesh definition tokens are a sub-category of definition tokens that can only be used in the names of objects but do not change the object into an invisible definition object. Objects that have one or more of these definition tokens are treated as visible objects and they govern some aspect of the faces of the mesh in that object.

❗ Each definition token may only appear once in a name field but a name may contain both definition tokens.

Definition	Default Token	Requirements	Maximum Count/Brick	Description
Color	c	See Defining Colors	Unlimited	Defines the color of the faces.
Coverage	See Defining Quad Sorting & Coverage	Must contain a face	Unlimited	Assigns the object's quads into a specific section in the brick.

Defining Quad Sections & Coverage

BLB files allow mesh faces to be sorted into seven sections: top, bottom, north, east, south, west, and omni. Quads in these sections may then be automatically hidden in-game using the coverage system, if it is defined in a meaningful way in the BLB file.

The coverage system allows the game to skip rendering quads that are completely covered by adjacent bricks improving the frame rate when a large number of bricks are on the screen at once. Quads are sorted into these sections by using one of the tokens below in the name of the object containing the faces to be sorted into that section. If a visible object has no quad sorting token specified, the omni section is used.

Default Token	Section
qt	Top
qb	Bottom
qn	North
qe	East
qs	South
qw	West
qo	Omni ("any" or "none", default)

❗ Sorting quads in this manner is pointless unless the Coverage property in the export dialog is enabled and at least one option is enabled.

❗ Due to how Blockland handles .blb files, ensure that north is assigned to faces facing the +Y direction, east is assigned to faces facing the +X direction, with south and west corresponding to -Y and -X respectively.

In the export dialog Coverage properties there are two options for each section/side of the brick:

Option	Description
Hide Self	For example when enabled for the top section, the game will not render the quads in the top section of this brick when the top area of this brick is completely covered.
Hide Adjacent	For example when enabled for the top section, the game will not render the quads in the bottom section of adjacent bricks on top of this brick if the coverage rules for those adjacent bricks are fulfilled.

Defining Colors

The exporter supports three methods for defining brick colors. To allow faces to be colored using the spray can tool in game do not assign a color those faces. See RGBA Color Format for a detailed explanation of how to write an RGBA color value.

Method	Overrides	Extent of Coloring	RGB Values	Alpha Value	Notes
Object Colors	In-game paint color	Entire object (color & alpha)	In object name after the Color token	In object name after the red, green, and blue values	Implemented only to support legacy brick models, not recommended for use.
Material Colors	Object Colors	Assigned faces (color & alpha)	In Material tab as Diffuse Color	In Material tab under Transparency in Alpha slider	The recommended method for defining color. Multiple materials may be used in a single object.
Vertex Colors	Material Colors	Entire object (per-vertex color), entire object (alpha)	In Data tab under Vertex Color as a vertex color layer, modified using the Vertex Paint mode	In Data tab under Vertex Color as the name of the vertex color layer	Creating a vertex color layers will color the entire object white, but the color of individual vertices may be changed.

There are three definition tokens that are specific to dealing with colors.

Token	Usable In	Description
blank	Material name	Ignore the material's color and do not write any color for the faces with this material assigned so they can be colored by the spray can in-game. This feature exists because an object that has a material, cannot have faces that do not have a material assigned to them.
cadd	Material name, vertex color layer name	Use this color as an additive color: add the values of this color to the spray can color in-game. For example to make the spray can color a little lighter use a dark gray color.
csub	Material name, vertex color layer name	Use this color as a subtractive color: subtract the values of this color from the spray can color in-game. For example to make the spray can color a lot darker use a light gray color.

RGBA Color Format

The exporter understands two ways of defining an RGBA color using text.

❗ Please note that you must use a comma character (,) as the decimal separator for floating point numbers.

1. The commonly used method of writing 4 integers that are in the range 0–255, where 0 is black, separated with a whitespace character such as a space. For example 127 255 10 191 for a yellow-green color that is 25% transparent. A full object name could be for example glass c 240 255 255 128.001.
   • In the above example the running index .001 that Blender added at the end would be removed by the exporter.
2. Writing 4 decimals in the range 0.0–1.0, where 0.0 is black, separated with a whitespace character such as a space. An object could have a name such as c 0,125 0,0 0,5 1,0 flower, for example.
   • The leading zero may be omitted.
   • Up to 16 decimals are supported.

Definition Objects

When a specific definition token is read in an object's name it is treated as a definition object. Definition objects contain non-visual data about the brick and as such are not exported as visual objects

Definition Object	Default Token	Requirements	Maximum Count/Brick	Must Be Within Bounds	Axis-Aligned	Brick Grid Aligned	Can Overlap	Description
Bounds	bounds	At least two vertices, must have volume	1	N/A	Yes (1)	Yes	N/A	Defines the dimensions or the size of the brick.
Collision	collision	At least two vertices, must have volume	10	Yes (2)	Yes	No	Yes	Defines a collision cuboid. See Defining Collision for more info.
Brick Grid	See Defining Brick Grid	At least two vertices, must have volume	Unlimited	Yes	Yes (1)	Yes	Yes (3)	Defines a volume in the brick grid to fill with a specific brick grid symbol.

(1) It is highly recommended to use axis-aligned cuboids to define bounds and the brick grid. However, if you insist on defining the size of your brick in monkey heads, you can. Only the axis-aligned bounding box of the bounds and brick grid objects are used.

(2) Collision boxes outside brick bounds are technically not invalid and the brick will function in-game. This behavior is not allowed by the exporter because collision outside brick bounds is horribly broken as it was never intended work in that manner.

(3) See Defining Brick Grid for the specific rules about overlapping brick grid definitions.

Defining Collision

Blockland bricks only supports AABB collision. In other words brick collision may only be defined using cuboids of varying sizes that align with the coordinate axes. You can rotate said cuboids however you want but that will not lead to rotated collision cuboids in-game. Only the the axis-aligned bounding box of the collision definition objects are used.

💡 Using any other shape than an axis-aligned cuboid to define collision is not recommended as it makes the Blender file more difficult to understand and also breaks the "what you see is what you get" principle.

Defining Brick Grid

Brick grid definitions represent a 3D volume in the 3D space the brick grid encompasses. You can imagine it as if the entire cuboidal shape of the brick would be filled with 1x1f plates and these volumes define the properties of all the 1x1f plates within that volume. Each brick grid definition has their own priority. When two or more brick grid definition objects overlap in 3D space, the one with the higher priority takes precedence and will overwrite the symbols in the brick grid that any definitions with lower priorities would have written.

❗ Be aware that if your brick does not contain a brickd definition on the bottom of the brick, the brick cannot be planted on other bricks or the ground.

Default Token	Brick Grid Symbol	Description
gridb	b	Bricks may be placed above and below this volume. This brick can be planted on the ground.
gridd	d	Bricks may be placed below this volume. This brick can be planted on the ground.
gridu	u	Bricks may be placed above this volume.
grid-	-	Bricks may be placed inside this volume. (I.e. empty space.) This is the default symbol, any volume that does not have a brick grid definition uses this symbol.
gridx	x	Bricks may not be placed inside this volume.

Brick Textures

Defining brick textures is done using Blender materials. To assign a brick texture to a face, assign a material to it containing a valid brick texture name (case insensitive):

• bottomedge
• bottomloop
• print
• ramp
• side
• top

If no brick texture is defined, side is used. Material name may contain other words as long as the brick texture name is separated from them with one whitespace character such as a space. A common combination is to define a brick texture name and the definition token blank (e.g. blank ramp or side blank) to allow the player to color the face in-game using the spray can.

UV Mapping

Manually defined UV coordinates must be stored in one or more UV layers that do not share a name with one of the automatically generated UV layers:

• TEX:BOTTOMEDGE
• TEX:BOTTOMLOOP
• TEX:PRINT
• TEX:RAMP
• TEX:TOP

Any data in UV layers with one the names above will the overwritten during automatic UV calculation.

❗ Note that BLB files only support storing quads. As such, any tris with UV coordinates will have their last UV coordinate duplicated to transform it into a quad. This may or may not cause visual distortion in the UV mapping.

If the Calculate UVs property is enabled, UV coordinates will be automatically calculated based on the dimensions of the quad and the name of the material assigned to it. (See Brick Textures to learn how to define brick textures with materials.) The generated coordinates are only guaranteed to be correct for strictly rectangular quads, for any other shapes the results may not be satisfactory. If using brick textures on non-rectangular quads it is recommended to manually define the UV coordinates for best results.

Rounded Values

Floating point numbers (numbers with a decimal point) contain inherent inaccuracies. For example when exporting a 1x1x1 brick model at the maximum accuracy the vertex coordinate of one of the corners is 0.5 0.5 1.5000000596046448. This causes the 1x1x1 brick to be 3.00000011920928955078125 plates tall instead of exactly 3.0 like it should. The only way to get fix this error is to round the vertex coordinates. Practically speaking it is impossible to visually discern the difference between a brick that is 3 plates tall versus one that is 3.00000011920928955078125 plates tall in the game. The only real benefit that comes from the rounding is nicer looking .BLB files.

The default value of 0.000001 was chosen through manual testing. Rest assured that the rounding will cause no visual oddities whatsoever because the value is so small. This was manually confirmed with a sphere brick made from 524288 quads. Moving the camera as close to the surface of the brick as the game was capable of rendering, the surface of the sphere appeared mathematically perfect because the distance between the vertices was less than the size of a single pixel.

❗ The exporter will only ever write up to 16 decimal places regardless of the precision of the value.

Floating Point Value	Rounded
Visible object vertex coordinates	Yes
Bounds object vertex coordinates	Yes
Collision object vertex coordinates	Yes
Brick grid object vertex coordinates	Yes
Normal vectors	Optional
RGBA color values	No
UV coordinates	No

Export Properties

The following user properties are present in the current version of the exporter.

Blender Properties

Bricks to Export

How many bricks to export in one go from the file.

Value	Description
Single	Export only one brick. (Default)
Multiple	Export one or more bricks. Shows additional settings when selected.

Brick Name from (Single Export)

Where the .BLB file name is defined.

Value	Description
Bounds	Brick name is defined in the Bounds object after the bounds definition token, separated with a whitespace character. Export file dialog is only used set to directory. (Default)
File	Brick name is the same as the file name. Can be manually set in the export file dialog.

Export Only (Single Export)

Which objects to process and export to the .BLB file.

Value	Description
Selection	Objects that are selected and have an orange outline. (Default)
Layers	All objects in the layers that are currently visible, regardless of selection.
Scene	All objects in the current scene. I.e. all objects in all layers regardless of the layer visibility.

Brick Names from (Multiple Export)

Where the names of the .BLB files are defined.

Value	Description
Bounds	Brick names are defined in the Bounds object after the bounds definition token, separated with a whitespace character. Export file dialog is only used set to directory. (Default)
Groups	Brick names are the same as the names of the groups name. Export file dialog is only used set to directory.

Bricks Defined by (Multiple Export)

How is a single brick defined.

Value	Description
Groups	Each brick is in its own group. Objects in multiple groups belong to multiple bricks. (Default)
Layers	Each brick is in its own layer. Objects in multiple layers belong to multiple bricks. When selected brick names must be defined in the Bounds object.

Export Bricks in (Multiple Export)

Which bricks to process and export to .BLB files.

Value	Description
Layers	Export all bricks in the layers that are currently visible. (Default)
Scene	Export all bricks in the current scene. I.e. all bricks in all layers regardless of the layer visibility.

Forward Axis

The Blender coordinate axis that will point forwards in-game when the player plants the brick directly in front of them without rotating it. Does not change the rotation of the objects in the Blender scene.

Value	Description
+X	Positive X-axis
+Y	Positive Y-axis (Default)
-X	Negative X-axis
-Y	Negative Y-axis

Scale

The scale of the brick in-game. Values outside the the range of 0.001–400.0 may be typed in manually. Does not change the scale of the objects in the Blender scene. See Brick Scale for additional information. (Default: 100%)

Apply Modifiers

Applies any modifiers on the object before exporting. Does not change the modifiers of the objects in the Blender scene. (Default: True)

Custom Definition Tokens

Allows you to specify the definition tokens the exporter uses. See Definition Tokens for more information. (Default: False)

💡 Enabling this property shows additional properties.

BLB Properties

Custom Collision

Export custom collision definitions if there are any. See Defining Collision. (Default: True)

Fallback Collision

The type of collision to calculate for the brick if no custom collision definitions are found. Enabling this property shows additional properties.

Value	Description
Bounds	Use the defined or calculated bounds of the brick as the collision cuboid. (Default)
AABB	Calculate the axis-aligned bounding box of all visible objects and use that as the collision cuboid.

Calculate Coverage

Enable coverage calculations. This is pointless unless Automatic Quad Sorting is enabled or at least one object has a quad sorting definition. See Defining Quad Sorting & Coverage for more information. (Default: False)

💡 Enabling this property shows additional properties.

Automatic Quad Sorting

Automatically calculate the correct section for quads that in the same plane as the bounding planes of the bounds object. This is pointless unless Coverage is enabled. (Default: True)

Use Material Colors

Assign face colors from object materials. (Default: False)

Use Vertex Colors

Assign face colors from vertex color layers. (Default: False)

Parse Object Colors

Assign face colors from object names. (Default: False)

Calculate UVs

Automatically calculate correct UV coordinates based on the brick texture name specified in the material name. See UV Mapping for more information. (Default: True)

Square Side UVs

Instead of attempting to calculate the appropriate UV coordinates for a face with the SIDE texture, use a square that takes up the full UV space instead. The UVs will be identical to that of the PRINT texture. Sometimes when the automatic side UV calculation fails miserably this option may produce a better result. (Default: False)

Store UVs

Write calculated UVs into Blender objects. Data in existing generated UV layers will be overwritten. See UV Mapping for a list of generated UV layer names. (Default: True)

Round Normals

Round vertex normals to the user-defined floating point value precision. If disabled normals will be written as accurately as possible but extraneous zeros will still be removed. (Default: False)

Precision

Allows you to specify a custom precision for floating point numbers. See Rounded Values for more details. (Default: 0.000001)

File Properties

Pretty Print

When enabled does not write extraneous zeros to the end of floating point numbers. Additionally if a numerical value is exactly equal to an integer, no decimal places are written. If disabled will write all floating point numbers using as many decimal places as used in the Precision property. (Default: True)

Write Log

Write a log file to the same folder as the exported brick detailing the export process. Shows additional settings when selected. (Default: True)

Only on Warnings

Write a log file only if warnings or errors occurred during the export process. (Default: True)

Terse Mode

When enabled does not write optional lines to the .BLB file such as the lines marking the different quad sections. Using this option is not recommended as it makes the .BLB file harder to read and understand. Although the file is shorter, the difference in file size is negligible. (Default: False)

Troubleshooting

Solutions to common issues with the BLB Exporter. If you have another issue with the exporter be sure to enable the Write Log property and export again. The log file may contain warnings or errors describing issues with the objects and how to fix them. Additional instructions on how to fix specific issues are detailed in the Warning & Error Log Messages section.

Automatically calculated UV coordinates for brick textures are distorted

The automatic UV calculation is only designed to work with rectangular quads. Manually define UV coordinates for non-rectangular quads.

Automatically calculated UV coordinates for brick textures are rotated incorrectly

The quad with incorrectly rotated UV coordinates (e.g. the lightest side of the SIDE texture pointing sideways instead of up) is not a perfect rectangle. Even one vertex being off by some minuscule, visually indistinguishable amount from a perfectly rectangular shape can cause the automatic UV calculation to incorrectly determine the rotation of the quad. Double check all 4 coordinates of the quad and manually correct any floating point errors. If working on axis-aligned quads or if the vertices should be on grid points snapping the coordinates of the problem quad to grid coordinates by selecting Mesh > Snap > Snap Selection to Grid in the 3D viewport toolbar usually fixes floating point errors.

The TOP brick texture has incorrect rotation in Blender

Blockland automatically performs rotations on the UV coordinates of the TOP brick texture during runtime so that the lightest side of the texture is always facing towards the sun. Because of this there is no correct way of representing the TOP brick texture in Blender. As a compromise the exporter will rotate the lightest side of the TOP brick texture to face towards the axis select in the Forward Axis property. This means the UV coordinates of the TOP brick texture in Blender may not match those in the written BLB file.

Warning & Error Log Messages

Detailed explanations of the warning and error messages logged by the program and directions on how to solve the associated issues. In the messages listed in this section the # character is used to represent a variable numerical value. Text in code tags describes a variable alphanumeric value, commonly the name of a Blender object.

Warnings

Warning log messages can be ignored as the issues are automatically corrected, but the resulting brick may not behave or look as excepted. It is recommended to manually adjust the brick until no warning messages are present in the output log.

Code	IOBLBW000
Message	Calculated bounds have a non-integer size # # #, rounding up.
Cause	No bounds object was defined and the axis-aligned bounding box calculated from the has non-integer dimensions when converted to brick space.
Effect	Brick dimensions of the calculated bounding box will be rounded up to ensure that collision cuboids (if any) still fit within the bounds.
Solutions	Recommended: Manually define a bounds object. Manually ensure that the visible objects of your brick model form an axis-aligned bounding box that has a valid size for a brick.

Code	IOBLBW001
Message	Defined bounds have a non-integer size # # #, rounding to a precision of #.
Cause	The axis-aligned bounding box calculated from the defined bounds object has non-integer dimensions as a brick.
Effect	The brick dimensions will be rounded to the specified precision.
Solution	Ensure that the defined bounds object aligns with the brick grid.

Code	IOBLBW002
Message	Brick name was supposed to be in the bounds definition object but no such object exists, file name used instead.
Cause	The "Brick Name(s) from" export property (either in single or multiple brick export mode) value was set to Bounds but no manually defined bounds object was found.
Effect	The file name specified in the export dialog is used as the name of the BLB file instead.
Solution	Create a bounds object and in the name of the object separate the name of the BLB file from the bounds definition token with a whitespace character.

Code	IOBLBW003
Message	Brick name was supposed to be in the bounds definition object but no name (separated with a space) was found after the definition token, file name used instead.
Cause	The "Brick Name(s) from" export property (either in single or multiple brick export mode) value was set to Bounds but no string was found after the bounds definition token in the name of the bounds object.
Effect	The file name specified in the export dialog is used as the name of the BLB file instead.
Solution	Separate the name of the BLB file from the bounds definition token with a whitespace character, such as a space.

Code	IOBLBW004
Message	No brick grid definitions found. Full cuboid brick grid may be undesirable.
Cause	There are no brick grid definition objects.
Effect	A full block brick grid will be generated. Brick will act as if it were a basic cuboid brick of that size.
Solution	Create brick grid definitions for the model.

Code	IOBLBW005
Message	# brick grid definition(s) found but was/were not processed. Full cuboid brick grid may be undesirable.
Cause	An error occurred for all brick grid definition objects when converting into a brick placement rule.
Effect	A full block brick grid will be generated. Brick will act as if it were a basic cuboid brick of that size.
Solution	Create valid brick grid definitions for the model.

Code	IOBLBW006
Message	# collision definition(s) found but was/were not processed.
Cause	An error occurred for all collision definition objects when calculating their dimensions.
Effect	The fallback collision will be used.
Solutions	Manually define valid collision objects. Enable the Calculate Collision export property.

Code	IOBLBW007
Message	No brick bounds definition found. Calculated brick size may be undesirable.
Cause	Brick did not have a bounds definition object.
Effect	The axis-aligned bounding box of all visible objects will rounded to the nearest brick dimensions and used as the brick bounds.
Solution	Create a bounds definition object.

Code	IOBLBW008
Message	Object 'object name' has # vertex color layers, only using the first.
Cause	The object had more than one vertex color layer.
Effect	Only the first vertex color layer is used.
Solution	Delete the additional vertex color layers.

Code	IOBLBW009
Message	Face has UV coordinates but no brick texture was set in the material name, using SIDE by default.
Cause	The material assigned to a face had no brick texture defined but the face had UV coordinates.
Effect	The side brick texture is used for the face.
Solution	Manually define brick textures in the names of the materials that are assigned to UV mapped faces.

Code	IOBLBW010
Message	No alpha value set in vertex color layer name, using 1.0.
Cause	The color defined in the vertex color layer did not contain an alpha value.
Effect	Alpha of 1.0 is used resulting in an opaque color.
Solution	Define the alpha value in the vertex color layer name.

Code	IOBLBW011
Message	# triangles converted to quads.
Cause	A mesh contained a triangle.
Effect	The triangle is forcefully converted into a quad by copying the first vertex and using that as the last vertex of a quad. This conversion has three different outcomes: If flat shading is used for the face there is no change visually and the face will look like a triangle in game. If the face and adjacent connected faces are planar and smooth shading is used there are no visual anomalies. If the face and adjacent connected faces are not planar and smooth shading is used there may be shading errors.
Solution	Do not use triangles in any meshes.

Code	IOBLBW012
Message	# n-gons skipped.
Cause	A mesh contained a face made from more than 4 vertices.
Effect	Faces made from more than 4 vertices are not exported.
Solution	Manually rebuild faces made from more than 4 vertices using quads.

Code	IOBLBW013
Message	Precision has too many decimal digits, using 16 instead.
Cause	The precision value set in the Precision property had more than 16 decimal digits.
Effect	If Pretty Print is disabled the number of decimal digits written to the BLB file is clamped to 16.
Solution	Only write up to 16 decimal places in the Precision value.

Errors

Errors are separated into two categories: fatal and non-fatal errors.

• Fatal errors cause the program execution to stop as there is insufficient or incorrect input data to process into a Blockland brick.
• Non-fatal errors occur when the exporter attempts to do something (due to invalid input data) that would have caused an error when loading or using the exported brick in game. Alternatively the user has attempted to do something that is explicitly not allowed by the exporter or would lead to a mathematical error.

It is recommended to manually adjust the brick until no error messages are present in the output log.

Fatal Errors

Fatal errors always lead to the program execution stopping.

Code	IOBLBF000
Message	When exporting multiple bricks in separate layers, a bounds definition object must exist in every layer. It is also used to provide a name for the brick.
Cause	The following export properties are set: Property Value Bricks to Export Multiple Brick Names from (Multiple Export) Bounds Bricks Defined by (Multiple Export) Layers And a visible layer did not contain a bounds definition object.
Reason	In the interest of promoting good workflow practices this is considered a fatal error instead of automatically naming the brick by the index of the layer it is contained in.
Solution	Ensure that there is exactly one valid bounds definition object in every visible layer.

Code	IOBLBF001
Message	When exporting multiple bricks in separate layers, the brick name must be after the bounds definition token (separated with a space) in the bounds definition object name.
Cause	The following export properties are set: Property Value Bricks to Export Multiple Brick Names from (Multiple Export) Bounds Bricks Defined by (Multiple Export) Layers And a bounds definition object name did not contain the name of the brick.
Reason	In the interest of promoting good workflow practices this is considered a fatal error instead of automatically naming the brick by the index of the layer it is contained in.
Solution	Ensure that each bounds definition object contains the name of that brick.

Code	IOBLBF002
Message	Unable to store UV coordinates in object 'object name' while it is in edit mode.
Cause	The Store UVs property is enabled and the exporter attempted to write UV coordinates to a Blender object that is currently in edit mode.
Reason	The authors have not bothered to find a way to automatically disable and re-enable the edit mode.
Solution	Confirm that you are not in the edit object interaction mode by changing to the Object Mode in the 3D viewport.

Code	IOBLBF003
Message	Brick has no volume, brick could not be rendered in-game.
Cause	The bounds definition object or the automatically calculated axis-aligned bounding box of the brick was smaller than 1 brick on one or more axis.
Reason	A brick size cannot be zero on any axis.
Solution	Recommended: Ensure that the manually defined bounds definition object is larger than a 1x1f plate brick. Ensure that the visible objects of the brick form an axis-aligned bounding box that is larger than a 1x1f plate brick.

Code	IOBLBF004
Message	Brick size (#x#x#) exceeds the maximum brick size of 64 wide 64 deep and 256 plates tall.
Cause	The bounds definition object or the automatically calculated axis-aligned bounding box of the brick is larger than maximum brick size supported by Blockland.
Reason	The maximum size of a single Blockland brick is 64 plates wide 64 plates deep and 256 plates tall.
Solution	Make your brick bounds smaller, while keeping in mind the rules regarding other definition objects.

Code	IOBLBF005
Message	No faces to export.
Cause	None of the had any faces.
Reason	Creating a brick with no visible faces is pointless.
Solution	Ensure that there is at least one face to export.

Code	IOBLBF006
Message	No objects to export.
Causes	Depends on the values of various export properties. Bricks to Export Export Only (Single Export) Cause Single Selection No objects were selected. Selected objects have an orange outline. Layers There are no objects in the currently visible layers. Scene None of the layers in the current scene contained any objects. Bricks to Export Export Bricks in (Multiple Export) Bricks Defined by (Multiple Export) Cause Multiple Layers Groups None of the groups in the current scene had any objects in the visible layers. Layers None of the visible layers contained any objects. Scene Groups None of the groups in the current scene contained any objects. Layers None of the layers in the current scene contained any objects.
Reason	No data to export, nothing to do.
Solutions	Depends on the values of various export properties. Bricks to Export Export Only (Single Export) Solution Single Selection Select some objects. Layers Select one or more layers with objects. Scene Add objects to a layer in the scene or check that you are not in the wrong scene. Bricks to Export Export Bricks in (Multiple Export) Bricks Defined by (Multiple Export) Solution Multiple Layers Groups Ensure that your groups have objects assigned to them and that you have selected layers with objects in them. Layers Select layers with objects. Scene Groups Add objects to a group in the current scene. Layers Add objects to a layer in the scene or check that you are not in the wrong scene.

Code	IOBLBF007
Message	Two or more brick grid definitions had the same priority.
Cause	Two or more user defined brick grid definition tokens had the same priority number.
Reason	The user-intended priority order of the tokens cannot be automatically determined.
Solution	Ensure that all custom brick grid definition tokens have a unique priority number.

Code	IOBLBF008
Message	No groups to export in the current scene.
Cause	The following export properties are set: Property Value Bricks to Export Multiple Bricks Defined by (Multiple Export) Groups And the current scene does not contain any groups with objects in visible layers.
Reason	No data to export, nothing to do.
Solution	When exporting multiple bricks in groups, ensure that there are groups to export.

Code	IOBLBF009
Message	Nothing to export in the visible layers of the current scene.
Cause	The following export properties are set: Property Value Bricks to Export Multiple Bricks Defined by (Multiple Export) Layers And the current scene does not contain any objects in visible layers.
Reason	No data to export, nothing to do.
Solution	When exporting multiple bricks in groups, ensure that there are groups to export.

Code	IOBLBF010
Message	Invalid floating point value given for floating point precision property.
Cause	The string specified in the Precision property was not a numerical value.
Reason	The numerical values that are rounded to combat floating point inaccuracies cannot be rounded unless the floating point precision is set.
Solution	Write a numerical value as the Precision property.

Non-Fatal Errors

Code	IOBLBE000
Message	Brick grid definition object 'object name' has vertices outside the calculated brick bounds. Definition ignored.
Cause	A brick grid definition object had vertices outside the automatically calculated brick bounds.
Reason	Blockland does not allow brick grid definitions outside the bounds of a brick.
Effect	The brick grid definition object is discarded.
Solutions	Recommended: Manually create a bounds definition object that properly fits around the defined brick grid. Ensure that the specified brick grid definition object is fully contained within the axis-aligned bounding box of the .

Code	IOBLBE001
Message	Brick grid definition object 'object name' has vertices outside the bounds definition object 'object name'. Definition ignored.
Cause	A brick grid definition object had vertices outside the bounds object.
Reason	Blockland does not allow brick grid definitions outside the bounds of a brick.
Effect	The brick grid definition object is discarded.
Solutions	Ensure that the specified brick grid definition object is fully contained within the bounds object. Make the bounds definition object larger.

Code	IOBLBE002
Message	Brick grid definition object 'object name' has no volume. Definition ignored.
Cause	The axis-aligned bounding box of a brick grid definition object was either a plane or a point.
Reason	A brick grid definition with no volume does not produce any brick placement rules when calculating the brick grid.
Effect	The brick grid definition object is discarded.
Solution	Ensure that the specified brick grid definition object is not a point or a plane and has some volume.

Code	IOBLBE003
Message	# collision cuboids defined but 10 is the maximum, only using the first 10.
Cause	More than 10 collision definition objects were found.
Reason	A BLB file may have a maximum of 10 collision boxes.
Effect	Only the 10 oldest objects marked as collision definitions will be used.
Solution	Delete the additional collision definition objects.

Code	IOBLBE004
Message	Collision definition object 'object name' has less than 2 vertices. Definition ignored.
Cause	A collision definition object had 1 or 0 vertices.
Reason	At least two points are required to specify a volume in three-dimensional space.
Effect	The specified collision definition object is discarded.
Solution	Ensure that the specified collision definition object has at least 2 vertices.

Code	IOBLBE005
Message	Collision definition object 'object name' has no volume. Definition ignored.
Cause	The axis-aligned bounding box of a collision definition object was either a plane or a point.
Reason	A two-dimensional collision box does nothing in game.
Effect	The collision definition object is discarded.
Solution	Ensure that the specified collision definition object is not a point or a plane and has some volume.

Code	IOBLBE006
Message	Collision definition object 'object name' has vertices outside the calculated brick bounds. Definition ignored.
Cause	A collision definition object had vertices outside the automatically calculated brick bounds.
Reason	Collision boxes outside the bounds of a brick cause strange behavior in game.
Effect	The collision definition object is discarded.
Solutions	Recommended: Manually create a bounds definition object that properly fits around the defined collision definition objects. Ensure that the specified brick grid definition object is fully contained within the axis-aligned bounding box of the .

Code	IOBLBE007
Message	Collision definition object 'object name' has vertices outside the bounds definition object 'object name'. Definition ignored.
Cause	A collision definition object had vertices outside the bounds object.
Reason	Collision boxes outside the bounds of a brick cause strange behavior in game.
Effect	The collision definition object is discarded.
Solutions	Ensure that the specified collision definition object is fully contained within the bounds object. Make the bounds definition object larger.

Code	IOBLBE008
Message	Object 'object name' cannot be used to define bounds, must be a mesh.
Cause	A non-definition token in its name.
Reason	Non-axis-aligned bounding box.
Effect	The specified object is ignored.
Solution	Remove the bounds definition token from the name of the object.

Code	IOBLBE009
Message	Object 'object name' cannot be used to define brick grid, must be a mesh.
Cause	A non-definition token in its name.
Reason	Non-axis-aligned bounding box.
Effect	The specified object is ignored.
Solution	Remove the brick grid definition token from the name of the object.

Code	IOBLBE010
Message	Object 'object name' cannot be used to define collision, must be a mesh.
Cause	A non-definition token in its name.
Reason	Non-axis-aligned bounding box.
Effect	The specified object is ignored.
Solution	Remove the collision definition token from the name of the object.

Code	IOBLBE011
Message	Bounds already defined by 'object name', bounds definition 'object name' ignored.
Cause	One brick contained more than one bounds definition object.
Reason	Although it is technically possible to calculate the axis-aligned bounding box of multiple bounds definitions and use that as the final bounds of the brick a feature like this would be confusing for beginner users and breaks the "what you see is what you get" principle of the exporter.
Effect	The oldest bounds definition object is used and the rest are discarded.
Solution	Delete the additional bounds definition objects.

Code	IOBLBE012
Message	Multiple brick grid definitions in object 'object name', only the first one is used.
Cause	A single definition object contained more than one brick grid definition token.
Reason	One brick grid definition object may only be used to define one brick placement rule.
Effect	Only the first brick grid definition token is used.
Solution	Delete the additional brick grid definition tokens.

Code	IOBLBE013
Message	More than 4 color values defined for object 'object name', only the first 4 values (RGBA) are used.
Cause	Object name contained more than 4 color values.
Reason	An RGBA color is be defined by exactly 4 numerical values: red, green, blue, and alpha.
Effect	Only the first 4 numbers are used as color values.
Solution	Remove the additional numbers.

Code	IOBLBE014
Message	Object 'object name' has # section definitions, only using the first one: section name
Cause	The object had more than one quad section definition token.
Reason	A single face cannot be in multiple quad sorting sections at the same time.
Effect	Only the first section definition token is used.
Solution	Delete the additional section definition tokens.

Code	IOBLBE015
Message	More than one brick texture name found in material 'material name', only using the first one.
Cause	The material name contained more than one brick texture name.
Reason	A single face cannot have multiple brick textures at the same time.
Effect	Only the first brick texture name is used.
Solution	Delete the additional brick texture names.

Contributors

• Nick Smith - The original source code for reading, processing, and writing Blender data into the .BLB format. A majority of his code has been rewritten since.
• Demian Wright - Significant extensions and rewrites to Nick's original code and all additional features.

* There's always a footnote, see the issue with the TOP brick texture.

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