Difference between revisions of "Using Blender"

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<!-- Updated for Blender 3.0 -->
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'''This is a basic crib sheet for creating a [[Mobs|mob]] in [http://www.blender.org/ Blender].''' It could be used to create any other [[mod]] relatively easily.
−
3D models can be used to change the appearance of [[Player|players]], [[Node|nodes]], [[mobs]] and other [[Entity|entities]].
+
<!--This was made using Blender 2.70, but instructions should also work for Blender 2.5 or 2.6 as menu structure is pretty similar (but possibly not 2.4 or prior).-->
  
−
If you need to create models for your [[mod]], it is recommended that you use [http://www.blender.org/ Blender].
+
=== On file formats ===
  
−
== Engine considerations ==
+
Minetest uses the 3D rendering library provided by [http://irrlicht.sourceforge.net/ '''Irrlicht'''].<ref>As stated on the [http://dev.minetest.net/Terminology Terminology page] of the developer Minetest Wiki</ref> As of version 1.8.1 Irrlicht can import the following mesh-formats<ref>[http://irrlicht.sourceforge.net/?page_id=45 Irrlicht Features] - section Supported Media Formats and a more detailed description of how to import the supported 3D-formats into Irrlicht [http://irrlicht.sourceforge.net/docu/classirr_1_1scene_1_1_i_scene_manager.html#a63894c3f3d46cfc385116f1705935e03 here]</ref>:
  
−
Before you begin making artwork for use with Minetest, there are a few things you should know.
+
Animated objects:
 +
* B3D files (.b3d, r, skeleton)
 +
* Microsoft DirectX (.x, r) (binary & text, skeleton)
 +
* Milkshape (.ms3d, r, skeleton)
 +
* Quake 3 models (.md3, r, morph)
 +
* Quake 2 models (.md2, r, morph)
  
−
=== Coordinate spaces ===
+
Static objects:
 +
* Irrlicht scenes (.irr, r/w)
 +
* Irrlicht static meshes (.irrmesh, r/w)
 +
* 3D Studio meshes (.3ds, r)
 +
* Alias Wavefront Maya (.obj, r/w)
 +
* Lightwave Objects (.lwo, r)
 +
* COLLADA 1.4 (.xml, .dae, r/w)
 +
* OGRE meshes (.mesh, r)
 +
* My3DTools 3 (.my3D, r)
 +
* Pulsar LMTools (.lmts, r)
 +
* Quake 3 levels (.bsp, r)
 +
* DeleD (.dmf, r)
 +
* FSRad oct (.oct, r)
 +
* Cartography shop 4 (.csm, r)
 +
* STL 3D files (.stl, r/w)
 +
* PLY 3D files (.ply, r/w)
  
−
Minetest uses a Lefthanded Y-up coordinate space. In a space like this:
+
The minetest engine does not make use of all of these formats though.  
−
* Z axis points "forward"
+
The server only accepts the following file formats for media<ref>As is hardcoded in the source file [https://github.com/minetest/minetest/blob/master/src/server.cpp#L2442 server.ccp near line 2442] as of July 2021</ref>:
−
* Y axis points "up"
 
−
* X axis points "right"
 
  
−
Blender uses a Righthanded Z-up coordinate space, where forward is instead the positive Y axis.
+
3d-Models:
−
Make sure that your models are facing that direction. When in doubt, hit G, Y, 1 - if the model has moved forward, that means it's facing the right axis. Otherwise you'll have to rotate it.
+
* .b3d (B3D)
 +
* .x  (Microsoft DirectX)
 +
* .md2 (Quake 2 models)
 +
* .obj (Alias Wavefront Maya /static)
  
−
Be sure to select Lefthanded Y-up in the exporter if it supports that, to avoid surprises.
+
Images (textures):
−
 
 
−
=== Coordinate scale ===
 
−
 
 
−
Minetest currently requires a 10x scale applied to entity models.
 
−
If you prefer making your models in a metric scale, you will have to set visual_size of entities to 10x. (Nodes do not require this.)
 
−
Otherwise, model your entities in a scale where 10 units equals one node.
 
−
 
 
−
=== Vertex format ===
 
−
 
 
−
Minetest currently uses the following vertex attributes:
 
−
* Vertex position
 
−
* Vertex normals
 
−
* One texture coordinate channel
 
−
 
 
−
=== File format support ===
 
−
 
 
−
Minetest currently supports the following media formats for 3D content:
 
−
 
 
−
Animated, skinned models:
 
−
* B3D files (.b3d)
 
−
* Microsoft DirectX (.x) (binary & text, compression is not supported)
 
−
 
 
−
Static meshes:
 
−
* OBJ (.obj)
 
−
 
 
−
Textures:
 
 
* .png
 
* .png
 
* .jpg
 
* .jpg
 
* .bmp
 
* .bmp
 +
* .tga
 +
* .pcx
 +
* .ppm
 +
* .psd
 +
* .wal
 +
* .rgb
  
−
Any formats not mentioned above but known to work in the past are considered deprecated and may not work in future versions. When in doubt, stick to PNG textures and the model formats listed above.
+
Sounds:
 +
* .ogg
  
−
Do not use .b3d and .x files for static meshes at the moment, Minetest currently spawns animated mesh scene nodes for these, which may result in reduced performance.
+
and for names, descriptions and other UI stuff the translation file format might also be usefull:
 +
* .tr
  
−
=== Picking a skinned mesh format ===
 
  
−
You have two skinned mesh formats to choose from, and both have their advantages and disadvantages.
+
'''Notes:''' All other media file formats including those Irrlicht might otherwise support are ignored. Different file formats may perform differently in other setups, DirectX and B3D allow animation.
 +
Animation in textures is simulated by rotating through linear aligned single frames within a given texture file, a technique called verticalframe animations in contrast to animation by layers as used by the gif format for example. (but this crib sheet doesn't cover all that)
  
−
* B3D
 
−
** [+] Binary format means a small size
 
−
** [-] Difficult to postprocess after exporting
 
−
** [-] Difficult to debug problems
 
  
−
* X (text version)
+
* If you want to be able to export from Blender in B3D (Blitz 3D) format (with 2.70)
−
** [+] Can be parsed easily with lua scripts
 
−
** [+] Can be easily generated by scripts
 
−
** [+] Easy to debug issues (you can just read it)
 
−
** [+] Can be optimized by quantizing some data
 
−
** [-] Blender exporter is kinda buggy and inefficient
 
−
** [-] Probably still bigger than an equivalent .b3d
 
  
−
''Avoid using the binary X format!'' It's actually just a tokenized version of the ASCII representation,
+
# Download the Blender export script B3DExport.py
−
and may actually be less efficient than a sufficiently optimized text .x file!
+
#On GNU/Linux: copy to <code>~/.config/blender/2.71/scripts/addons</code><!--On Windows: copy to <code>C:\Program Files\Blender\2.71\scripts\addons--><br /> Alternatively, you can skip this step and see step 4 to see a different method*.
−
 
+
# Open Blender
−
=== Animation support ===
+
# In Blender open the menu File/User Preferences/Addons. *From here you can press 'Install Add-on from File', navigate to the <code>.py</code> file, and press 'Install'. Now go to File/User Preferences/Addons/Import Export/B3D (Blitz 3D) Model Exporter.
−
 
+
# Tick the box on the left to enable it<br /> (If you want .x (directX) then find this and enable it too.)
−
Animation is currently only supported in the form of playing ranges on a single timeline. Do not attempt to export separate actions, instead use the Nonlinear Animation (NLA) editor to arrange your actions into a single strip for export.
+
# While you're in preferences on the file tab you may want to enable Save&Load/Compress File (for much smaller saved files), and Autosave/Keep Session (to save on exit)
−
 
+
# Save User Settings
−
Keyframes are always interpolated linearly in the game.
+
# Close Preferences Window
−
 
 
−
=== Materials and textures ===
 
−
 
 
−
Multiple materials are allowed on all mesh formats that we support. You can assign different textures to each material slot in the lua API, both on nodes and on entities.
 
−
 
 
−
Use only one UV coordinate set for your models.
 
−
 
 
−
=== Optimizing your model for network transfer ===
 
−
 
 
−
Text formats like .obj and the text variant of .x may be optimized by removing unnecessary characters and truncating decimal digits. This will make your mod download much faster when hosted on a server or downloaded from the ContentDB.
 
−
 
 
−
== Working with Blender ==
 
−
 
 
−
=== Best practices ===
 
−
[[File:Blender LockTransforms.png|thumbnail|right|Locking your objects can prevent accidents from happening.]]
 
−
* Keep your scene free from unnecessary clutter.
 
−
* Always give your objects, armature bones and other assets meaningful names.
 
−
* Lock the transformations of objects and bones that should not be moving, rotating or scaling.
 
−
* Apply all object transforms before exporting. Your armature and meshes should probably all have an identity transform, that is, zero position and rotation and 1.0 scale.
 
−
* Use only armature bones to animate the model.
 
−
* Keep your animations in Actions and use the NLA editor to arrange them in a strip for exporting.
 
−
* Keep your .blend files somewhere close to or inside the mod, but not in the ./models/ folder itself.
 
−
* Try to set up your materials and the viewport to resemble how things would look like in the game.
 
−
* Reference textures from the mod's ./textures/ folder directly instead of packing them or using different files. This will make it easier to keep your assets synced.
 
−
 
 
−
==== Setting up a reference scene ====
 
−
[[File:Blender LinkedFloor.png|thumbnail|right|A reference environment can help you maintain a sense of scale when making your models.]]
 
−
It's a good idea to set up your scene background to resemble a portion of the game world. You can make yourself a reference scene like this and re-use it.
 
−
 
 
−
# Open a new .blend file for this purpose.
 
−
# Arrange some boxes to act as nodes, and map them with the textures of said nodes.
 
−
## Make sure that you have a floor where the floor should be to place the mob or character on.
 
−
## ''Join'' meshes together to reduce clutter.
 
−
# Mark all the objects as unselectable and lock their transforms.
 
−
# Save this .blend somewhere.
 
−
# Whenever you make a new model, use the ''File -> Link'' feature to import this environment.
 
−
# The linked objects are still unselectable, so they should not interfere with your work.
 
−
 
 
−
=== Blender 2.80 and later ===
 
  
−
==== Setting up the 3D view to look correctly ====
+
* If you want to import, install version 2.49, save as a Blender file, then open with 2.70 to edit.
  
−
* Use exactly 1 viewport sample in the render properties to make the viewport look more or less how it would look in the game.
+
* Another script is the [https://github.com/joric/io_scene_b3d io_scene_b3d] script by joric for Blender 2.80 that may work with Blender 2.79/2.9 (as of Jan.2021) versions. 
−
* Disable all postprocessing effects.
+
* Yet another version of [https://github.com/GreenXenith/io_scene_b3d io_scene_b3d] is maintained by GreenXenith (as of march 2020)<ref>As mentioned in the forum thread: [https://forum.minetest.net/viewtopic.php?f=47&t=24292 Which tools to export animated models?]</ref>.
−
* In Color Management, use the Standard transform with 1.0 gamma, or a Raw view transform with 2.2 gamma. Do not use curves.
+
* A python script to export from Blender to DirectX format .x is [https://github.com/minetest/io_scene_x io_scene_x] by hecktest. It is written to work with version 2.8 but this plugin is known to work in Blender versions up to 3.0.0 Alpha as of July 2021. As minetest uses a lefthanded Y-up coordinate space, you may have to adjust some values according to a matrix shown in the readme.md file
−
* Use an Emission shader node in the shader editor for unshaded preview.
 
  
−
== Create a basic mob for testing ==
+
== Begin with a basic mob ==
  
 
To create a basic mob, copy an animal from [https://github.com/sapier/animals_modpack animals_modpack]-2.3.6.
 
To create a basic mob, copy an animal from [https://github.com/sapier/animals_modpack animals_modpack]-2.3.6.
Line 131: Line 84:
 
You can edit speed, acceleration, etc as you wish.
 
You can edit speed, acceleration, etc as you wish.
  
−
== Making a mesh ==
+
=== Create a 3D model ===
 +
 
 +
Don't bother with materials – Minetest doesn't handle them – you need a [[Help:Creating texture packs|texture]] to define any colours.
 +
If you want your model to walk forwards, you must create it with “forward” pointing in the +ve x direction (i.e. right when you select view point '''KP 7''', or facing in the direction of the red “x” arrow when an object is selected).
 +
 
 +
==== Create object ====
  
−
# In the 3D View, use the object mode (dropdown in 3D viewport)
+
# In 3D View
 +
# If not already active switch to object mode (dropdown in 3D viewport)
 
# Add objects (eg 3D Menu → Add → Mesh → Cube)
 
# Add objects (eg 3D Menu → Add → Mesh → Cube)
 
# Move around by right-clicking to select and dragging arrows.<br /> '''B''' box/border select. '''G''' grab to move.<br /> Resize or rotate using the properties viewport (has a row of camera, cube, spanner, etc at top)
 
# Move around by right-clicking to select and dragging arrows.<br /> '''B''' box/border select. '''G''' grab to move.<br /> Resize or rotate using the properties viewport (has a row of camera, cube, spanner, etc at top)
 
# Select the cube
 
# Select the cube
 
# Use rotation and scale to transform objects<br /> [See the hundreds of Blender tutorials for more advanced editing techniques.]
 
# Use rotation and scale to transform objects<br /> [See the hundreds of Blender tutorials for more advanced editing techniques.]
−
# Create and transform cubes until you have the shape that you want
 
−
# Select all the cubes and ''Join'' them into one object
 
−
# Apply the resulting object's transform and lock it. Your model is now ready.
 
  
−
== Saving your work ==
+
==== Save primary Blender model ====
  
 
# Save as a Blender file (Ctrl-S or File → Save)
 
# Save as a Blender file (Ctrl-S or File → Save)
 
# Save with the name: yourname.blend (or similar)
 
# Save with the name: yourname.blend (or similar)
 +
# You might also want to save a separate “unjoined” copy before the following join operation, as you won't be able to access the base components afterward
  
−
== Texturing ==
+
=== Texturing ===
−
<!-- todo: clean this up -->
 
  
 
When the basic model is completed, you'll need to create a texture.
 
When the basic model is completed, you'll need to create a texture.
  
 +
# Switch to Object mode
 +
##  Press '''A''' (perhaps twice) to select all objects
 +
##  '''Ctrl + J''' to join all objects in a model together
 
# Switch to Edit Mode
 
# Switch to Edit Mode
 
##  Mesh/UV Unwrap/Smart UV Project [see one of the many UV Mapping tutorials if you want seams to match, etc]<br />[optional] Set island margin to 0.004 (this leaves a gap between faces, so there will be less risk of bleeding of colour across sharp edges. 0.002 is approx 1 pixel for a 512 pixel image)
 
##  Mesh/UV Unwrap/Smart UV Project [see one of the many UV Mapping tutorials if you want seams to match, etc]<br />[optional] Set island margin to 0.004 (this leaves a gap between faces, so there will be less risk of bleeding of colour across sharp edges. 0.002 is approx 1 pixel for a 512 pixel image)
Line 173: Line 132:
 
## To paint only particular faces, click the face Menu/faceselect (the cube with grid pattern on the face), you will then be able to select an entire face/s with R click (or shift R-click for multiple faces).
 
## To paint only particular faces, click the face Menu/faceselect (the cube with grid pattern on the face), you will then be able to select an entire face/s with R click (or shift R-click for multiple faces).
 
## Change colour, strength, radius, curve… and paint the different parts as you wish – painting in either 3D or UV Mesh windows.<br />NB the colour picker has an eyedropper to copy the colour from within the 3D or UV Map windows – just click on the currently displayed colour (under the colour wheel) to bring it up.
 
## Change colour, strength, radius, curve… and paint the different parts as you wish – painting in either 3D or UV Mesh windows.<br />NB the colour picker has an eyedropper to copy the colour from within the 3D or UV Map windows – just click on the currently displayed colour (under the colour wheel) to bring it up.
−
 
−
== Skinning ==
 
−
 
−
# Create an armature at the scene's origin.
 
−
# Enter ''Edit Mode'' and extrude, duplicate and transform the bones to set the skeleton up.
 
−
# Select the mesh, then the armature, and parent. Use empty groups, or automatic weights.
 
−
## If you used empty groups or need to correct the auto weights, select the mesh and switch to ''Weight Paint'' mode and bind vertices to bones by selecting a vertex group and painting the vertices in the 3D view.
 
−
## If you need to bind a portion of the mesh rigidly, enter ''Edit Mode'' with the mesh selected, and select the vertices that you want to bind. Select the appropriate vertex group in the Properties window. Then, click Remove and then Assign with the weight slider set to 1. Now the vertices will be bound rigidly to that bone only.
 
−
## Use ''Linked Select'' to quickly select a contiguous region of a mesh.
 
  
 
== Animation ==
 
== Animation ==
  
−
[[File:Blender AnimLayout.png|thumbnail|right|An example window layout for working with animations.]]
+
# Make sure your mesh is child of Armature.
 +
# Make sure there's only one bone parenting all others (having a child bone being parent of another one is no problem).
 +
# All faces need to be members of a vertex group.
 +
# Make sure all of your vertex groups have same name as at least one bone.
 +
# Don't forget to export animation when exporting to .x file.
  
−
When animating, use the ''Dope Sheet'' in the ''Action Editor'' mode instead of the timeline. Also have a ''Nonlinear Animation'' (NLA) window open for arranging and mixing the actions later.
+
== Save your work and export the files ==
  
−
=== Making an Action ===
+
# Save the mesh
−
[[File:Blender FakeUser.png|thumbnail|right|Check this to avoid losing your work.]]
+
## Export as a .b3d file (File/Export/B3D)
−
# Select your armature and enter the ''Pose Mode''.
 
−
# Create a new action by hitting the ''New'' button in the action editor.
 
−
# Rename your action to something like "Idle" or "Running".
 
−
# Click the ''Fake User'' icon to make sure this action is not lost when you save and reload the file.
 
−
# Scrub to the appropriate time code (frame number) in the dopesheet.
 
−
# Select and position a bone or several of them.
 
−
# Set a keyframe. The key should appear in the dopesheet window, and a channel will be made for the bone if it doesn't already exist.
 
−
# Animate the rest of the bones in this way until the action looks good.
 
−
 
 
−
Be sure to set one keyframe for all bones at the beginning and end frames of the action, otherwise motion may "bleed" between various actions.
 
−
 
 
−
==== Looping an Action ====
 
−
[[File:Blender CyclicFCurves.png|thumbnail|left|Apply this modifier to your channels to loop them.]]
 
−
A naively created looping animation will visibly slow down and restart with every cycle, even if you use an identical pose for the beginning and end keys.
 
−
 
 
−
To make an action loop correctly, you need to add a looping F-curve modifier to all your animation curves (dopesheet channels).
 
−
 
 
−
# Select all the '''channels''' in the dopesheet. Make sure you're selecting channels, not keyframes - hover your cursor over the channel names and hit 'A' once or twice until they all light up.
 
−
# Apply the ''Make Cyclic'' operator. (Use the search bar!) Your animation should now loop correctly.
 
−
 
 
−
=== Arranging Actions in NLA tracks ===
 
−
[[File:Blender NLA.png|thumbnail|left|Mixing actions can save you a lot of time.]]
 
−
In order to place an action in a track, you first need to push it down while it is selected.
 
−
 
 
−
It is possible to have many tracks and mix different animations by playing them simultaneously, which can save you a lot of work. For example, you can animate hand poses separately from the usual animations and only switch between them in another track. If you want to do this, you will probably want to utilize ''Keying Sets'' and ''Armature Layers'' to keep bone groups separate.
 
−
 
 
−
=== Setting the animation range ===
 
−
 
 
−
Before you export, you need to make sure that the scene's animation range encompasses all the actions that you wish to export.
 
−
 
 
−
You might want to set up some hotkeys so that you can easily do this without having to use the ''Timeline'' or ''Properties'' windows.
 
−
 
 
−
== Exporting ==
 
−
 
 
−
# Save your scene
 
−
## Export as a .b3d or .x file if skinned, or .obj if static
 
 
## Save with the name: models/animal_yourname.b3d
 
## Save with the name: models/animal_yourname.b3d
 +
## Don't forget to look for and OK the overwrite message if needed or it will disappear and you won't have saved your file.
 
# Save the texture
 
# Save the texture
 
## UV Window → Image → Save As Image
 
## UV Window → Image → Save As Image
 
## Save with the name: textures/animal_yourname_yourname_mesh.png
 
## Save with the name: textures/animal_yourname_yourname_mesh.png
−
 
−
=== Exporting OBJ ===
 
−
 
−
OBJ file support is built into most known versions of Blender, so just use the provided built-in plugin.
 
−
 
−
There is no need to write the MTL file as Minetest will not parse it.
 
−
 
−
=== Exporting B3D ===
 
−
 
−
==== Installing the exporter ====
 
−
 
−
# Download the Blender export script B3DExport.py
 
−
# Open Blender
 
−
# In Blender open the menu File/User Preferences/Addons. *From here you can press 'Install Add-on from File', navigate to the <code>.py</code> file, and press 'Install'. Now go to File/User Preferences/Addons/Import Export/B3D (Blitz 3D) Model Exporter.
 
−
# Tick the box on the left to enable it<br />
 
−
# Save User Settings
 
−
# Close Preferences Window
 
−
 
−
==== Blender 2.79 and earlier ====
 
−
 
−
Use the [https://github.com/minetest/B3DExport B3DExport] script maintained as part of the Minetest project. 
 
−
 
−
==== Blender 2.80 and later ====
 
−
 
−
A working exporter is maintained at [https://github.com/GreenXenith/io_scene_b3d io_scene_b3d] by GreenXenith (as of march 2020)<ref>As mentioned in the forum thread: [https://forum.minetest.net/viewtopic.php?f=47&t=24292 Which tools to export animated models?]</ref>.
 
−
 
−
==== Importing ====
 
−
If you want to import, install version 2.49, save as a Blender file, then open with 2.70 to edit.
 
−
 
−
=== Exporting X ===
 
−
 
−
==== Blender 2.79 and earlier ====
 
−
Versions of Blender before 2.8 already come with an .x exporter capable of producing text .x files.
 
−
 
−
==== Blender 2.80 to 3.0 ====
 
−
A version of the exporter updated for 2.8 API changes is hosted here: [https://github.com/minetest/io_scene_x io_scene_x]
 
−
 
−
As of 7/2020 this exporter is known to work with Blender 3.0 Alpha
 
−
 
−
The README.md file in that repository contains instructions on how to deal with coordinate space and attachment problems.
 
  
 
== Create or copy the inventory [http://dev.minetest.net/texture texture] ==
 
== Create or copy the inventory [http://dev.minetest.net/texture texture] ==

Revision as of 09:23, 19 November 2021

This is a basic crib sheet for creating a mob in Blender. It could be used to create any other mod relatively easily.

On file formats

Minetest uses the 3D rendering library provided by Irrlicht.[1] As of version 1.8.1 Irrlicht can import the following mesh-formats[2]:

Animated objects:

  • B3D files (.b3d, r, skeleton)
  • Microsoft DirectX (.x, r) (binary & text, skeleton)
  • Milkshape (.ms3d, r, skeleton)
  • Quake 3 models (.md3, r, morph)
  • Quake 2 models (.md2, r, morph)

Static objects:

  • Irrlicht scenes (.irr, r/w)
  • Irrlicht static meshes (.irrmesh, r/w)
  • 3D Studio meshes (.3ds, r)
  • Alias Wavefront Maya (.obj, r/w)
  • Lightwave Objects (.lwo, r)
  • COLLADA 1.4 (.xml, .dae, r/w)
  • OGRE meshes (.mesh, r)
  • My3DTools 3 (.my3D, r)
  • Pulsar LMTools (.lmts, r)
  • Quake 3 levels (.bsp, r)
  • DeleD (.dmf, r)
  • FSRad oct (.oct, r)
  • Cartography shop 4 (.csm, r)
  • STL 3D files (.stl, r/w)
  • PLY 3D files (.ply, r/w)

The minetest engine does not make use of all of these formats though. The server only accepts the following file formats for media[3]:

3d-Models:

  • .b3d (B3D)
  • .x (Microsoft DirectX)
  • .md2 (Quake 2 models)
  • .obj (Alias Wavefront Maya /static)

Images (textures):

  • .png
  • .jpg
  • .bmp
  • .tga
  • .pcx
  • .ppm
  • .psd
  • .wal
  • .rgb

Sounds:

  • .ogg

and for names, descriptions and other UI stuff the translation file format might also be usefull:

  • .tr


Notes: All other media file formats including those Irrlicht might otherwise support are ignored. Different file formats may perform differently in other setups, DirectX and B3D allow animation. Animation in textures is simulated by rotating through linear aligned single frames within a given texture file, a technique called verticalframe animations in contrast to animation by layers as used by the gif format for example. (but this crib sheet doesn't cover all that)


  • If you want to be able to export from Blender in B3D (Blitz 3D) format (with 2.70)
  1. Download the Blender export script B3DExport.py
  2. On GNU/Linux: copy to ~/.config/blender/2.71/scripts/addons
    Alternatively, you can skip this step and see step 4 to see a different method*.
  3. Open Blender
  4. In Blender open the menu File/User Preferences/Addons. *From here you can press 'Install Add-on from File', navigate to the .py file, and press 'Install'. Now go to File/User Preferences/Addons/Import Export/B3D (Blitz 3D) Model Exporter.
  5. Tick the box on the left to enable it
    (If you want .x (directX) then find this and enable it too.)
  6. While you're in preferences on the file tab you may want to enable Save&Load/Compress File (for much smaller saved files), and Autosave/Keep Session (to save on exit)
  7. Save User Settings
  8. Close Preferences Window
  • If you want to import, install version 2.49, save as a Blender file, then open with 2.70 to edit.
  • Another script is the io_scene_b3d script by joric for Blender 2.80 that may work with Blender 2.79/2.9 (as of Jan.2021) versions.
  • Yet another version of io_scene_b3d is maintained by GreenXenith (as of march 2020)[4].
  • A python script to export from Blender to DirectX format .x is io_scene_x by hecktest. It is written to work with version 2.8 but this plugin is known to work in Blender versions up to 3.0.0 Alpha as of July 2021. As minetest uses a lefthanded Y-up coordinate space, you may have to adjust some values according to a matrix shown in the readme.md file

Begin with a basic mob

To create a basic mob, copy an animal from animals_modpack-2.3.6. Then in the init.lua you only have to do a search and replace of the name of the animal, and delete any irrelevant code. You can edit speed, acceleration, etc as you wish.

Create a 3D model

Don't bother with materials – Minetest doesn't handle them – you need a texture to define any colours. If you want your model to walk forwards, you must create it with “forward” pointing in the +ve x direction (i.e. right when you select view point KP 7, or facing in the direction of the red “x” arrow when an object is selected).

Create object

  1. In 3D View
  2. If not already active switch to object mode (dropdown in 3D viewport)
  3. Add objects (eg 3D Menu → Add → Mesh → Cube)
  4. Move around by right-clicking to select and dragging arrows.
    B box/border select. G grab to move.
    Resize or rotate using the properties viewport (has a row of camera, cube, spanner, etc at top)
  5. Select the cube
  6. Use rotation and scale to transform objects
    [See the hundreds of Blender tutorials for more advanced editing techniques.]

Save primary Blender model

  1. Save as a Blender file (Ctrl-S or File → Save)
  2. Save with the name: yourname.blend (or similar)
  3. You might also want to save a separate “unjoined” copy before the following join operation, as you won't be able to access the base components afterward

Texturing

When the basic model is completed, you'll need to create a texture.

  1. Switch to Object mode
    1. Press A (perhaps twice) to select all objects
    2. Ctrl + J to join all objects in a model together
  2. Switch to Edit Mode
    1. Mesh/UV Unwrap/Smart UV Project [see one of the many UV Mapping tutorials if you want seams to match, etc]
      [optional] Set island margin to 0.004 (this leaves a gap between faces, so there will be less risk of bleeding of colour across sharp edges. 0.002 is approx 1 pixel for a 512 pixel image)
  3. Move mouse to the top of the 3D window to get and up/down arrow. Right click/split window and size to 50:50.
    1. On the R hand new window select the litle cube (3D viewport) icon and switch to UV Map viewport
    2. LowMenubar:New
      1. Set name - eg 'yourname UV Map'
      2. Click UV Test Grid (optional)
      3. OK (=Save)
        [if you want to resize the image use a power of 2 (512/1024/etc) for x and y dimensions as it significantly speeds processing]
    3. LowMenubar:Image → Pack as PNG → Accept warning (this ensures you will save a copy of the image within the .blend file (I think in 2.4 this may have to be updated manually, but the tickbox in 2.7 implies is should be saved with the rest of the file)
    4. Check UV map fits on image - adjust with: G - move, R - rotate, S - scale (menu:UV → Transform)
      The UV vertices won't always align to pixel boundaries, which means if you don't use 'island margin' above, then painting on one face may also unavoidable paint onto another face. There is reference in the manual to a UV snap-to-pixel option (to align UV vertices to pixel edges) but I haven't figured how to access it yet (and it would only perfectly stop bleed for horizontal or vertically aligned vertices).
  4. In 3D View window
    1. Switch to Texture Paint (from Edit Mode)
    2. in the Toolbar set:-
      1. Brush
        Select white (should be selected by default)
        Strength 1.0 (ie 100% replacement of the underlying colour)
        Radi 500 (or whatever brush radius you want)
      2. Curve
        select the square profile if you want a solid colour brush
        select the 'normal distribution curve' if you want a fading brush
        (or any other profile you like)
  5. UV Map window
    1. Switch to Paint (from View)
    2. Paint the entire object white (or some other basecoat). This is easiest to do in UV Map window
  6. In 3D View window
    1. To paint only particular faces, click the face Menu/faceselect (the cube with grid pattern on the face), you will then be able to select an entire face/s with R click (or shift R-click for multiple faces).
    2. Change colour, strength, radius, curve… and paint the different parts as you wish – painting in either 3D or UV Mesh windows.
      NB the colour picker has an eyedropper to copy the colour from within the 3D or UV Map windows – just click on the currently displayed colour (under the colour wheel) to bring it up.

Animation

  1. Make sure your mesh is child of Armature.
  2. Make sure there's only one bone parenting all others (having a child bone being parent of another one is no problem).
  3. All faces need to be members of a vertex group.
  4. Make sure all of your vertex groups have same name as at least one bone.
  5. Don't forget to export animation when exporting to .x file.

Save your work and export the files

  1. Save the mesh
    1. Export as a .b3d file (File/Export/B3D)
    2. Save with the name: models/animal_yourname.b3d
    3. Don't forget to look for and OK the overwrite message if needed or it will disappear and you won't have saved your file.
  2. Save the texture
    1. UV Window → Image → Save As Image
    2. Save with the name: textures/animal_yourname_yourname_mesh.png

Create or copy the inventory texture

Find or create a nice graphic to be the image in the inventory.
A flat texture can be created with a 6 sided cube model (eg animal_yourname_yourname.png)
The inventory image is animal_yourname_yourname_item.png
(Remember to respect copyright – use screenshots of your model, perhaps with the help of a “green screen” for transparency, if you want a simple free graphic. To turn off the 3D viewport grid floor open the propertles menu (+ at top R of window), and untick display/grid floor).

Rendering the model

If you want to be able to render the model (F12'), you'll first need to do the following steps to enable the texture:

  1. In 3D edit view. Add → Lamp → Hemi. You might need to move this around to adjust lighting direction, but probably not.
  2. In properties viewpane:-
  3. Select checkered box tab,
    1. Change texture type to Image → Movie,
    2. Click on image dropdown below this and select your UV texture image,
    3. Under mapping dropdown change coord to UV.

Now, rendering should work…

Notes and references

  1. ↑ As stated on the Terminology page of the developer Minetest Wiki
  2. ↑ Irrlicht Features - section Supported Media Formats and a more detailed description of how to import the supported 3D-formats into Irrlicht here
  3. ↑ As is hardcoded in the source file server.ccp near line 2442 as of July 2021
  4. ↑ As mentioned in the forum thread: Which tools to export animated models?
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