blender-to-gmstudio / blender-gms-vtx-buffer

Generic Blender exporter for GameMaker that exports highly customizable vertex formats

Blender to GameMaker Vertex Buffer Exporter

This exporter can be used to export all kinds of vertex formats.

Description

• Generates a file with vertex buffer contents
• Applies transforms & modifiers
• Generates an accompanying JSON file that describes all exported content
• Features:
  • Customizable vertex format, allowing for:
    • Static geometry batches
    • Dynamic geometry batches (mesh data + offset per mesh/object in json file)
    • Batched morphs
  • Morphs & per-frame stuff, including interpolation
  • Basic export of any material/shader properties

Installing the plugin in Blender

• In Blender, go to Edit > Preferences
• Go to tab Add-ons and select Install from File...
• Select the zip file blender-gms-vtx-buffer-v1.0.13.zip and confirm (the filename will be different for another version of the exporter)
• Tick the checkbox next to Import-Export: Export GameMaker Vertex Buffer
• Click Save User Settings
• The plugin is now ready to be used

Installing presets

Preset files are Python files (.py) that contain an operator preset's code. These files need to placed in the right directory for the operator to detect them. To install a new preset:

• Navigate to %USERPROFILE%\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\presets\operator
• Create a new directory with the name export_scene.gms_vtx_buffer. This is the bl_idname of the operator.
• Place the preset file in this directory The included presets can be installed from the add-on's preferences

Usage

In Blender

• Select one or more objects that you want to export
• Export using an existing export preset or create your own configuration

In GameMaker

• Load the file as a buffer using buffer_load.
• Define the vertex format, either in the code editor or load it from the JON file.
• Create a vertex buffer from the buffer using the created vertex format.
• Create a shader with vertex attributes that correspond to the vertex format.
• Draw the model using the shader.

To export the vertex format, tick Export Object Data. This generates an additional .json file which contains a description of the vertex format. The format description can be found under the key blmod/mesh_data/format.

The add-on does not currently come with any code for GameMaker. Many examples will be added to and explained in the wiki.

Advanced

More info and examples can be found in the wiki: https://github.com/blender-to-gmstudio/blender-gms-vtx-buffer/wiki

Creating vertex formats

See the wiki on defining vertex formats.

blender-gms-vtx-buffer's Issues

Error on exporting via the Python console

line 177, in export
    for i, obj in enumerate(mesh_selection): obj.batch_index = i   # Guarantee a predictable batch index
AttributeError: 'Object' object has no attribute 'batch_index'

This occurred with this call:
bpy.ops.export_scene.gms_vtx_buffer(filepath="C:/Users/bart_/Desktop/test.vbx",selection_only=True,vertex_format=[],reverse_loop=True,export_mesh_data=True,export_json_data=False,export_images=False)

Skeletal animation

Triangle vertex ordering isn't preserved between frames

A quick fix is to triangulate the model manually before export but this is not a user-friendly way of doing it

Have a look at the triangulation modifier options to see if we can get this consistent

Add custom map

This was lost when going back to v0.8

Export to glTF format?

The file format currently in use by the exporter looks a lot like glTF.
It'd be a good thing to standardize this exporter's format further to be prepared for the future.
There is no use keeping a custom file "json+binary" format when an industry standard exists.
Only the contents of the JSON file will need to be modified. The binary data remains the same.

Although this isn't high on the priority list, it's definitely something to seriously consider.

Warning is shown when EnumProperty index is out of bounds

Related to #14
This issue occurs when the EnumProperty's current index is outside the range of the new length of the items after an update.
Issue added only for documentation purposes.
It's just a warning so this currently won't be fixed.

Global scale factor

Add a scale factor that's applied to all exported meshes.

Custom json string to map any value to another value

Like the functionality the exporter had before

Further customization of export

Add support for "mesh-like" object types

Preset attribute writing order causes errors

Issue for this blocking issue #13 in the old repository
Working solution is in this gist

Fix vertex color export

It appears that vertex colors in Blender might now stored in a different property, since a recent release.
Find out if anything needs to be changed in the exporter and change it if that is the case.

The conversions module is loaded from Blender's directory rather than the plugin's directory

This works on my computer since I had the file there for testing but not on any other

Easy fix:

import conversions

Becomes:

from . import conversions

Filter contents of bpy.data in json based on selection

Add an option to export a header/footer that can store a bit of metadata

• Will allow for some 'MESH' object metadata to be written to file in a structured format
• The export of the header/footer should make use of the same features/functions that are used by the vertex attribute export (e.g. define format and pre-processing function)
• Important things to consider are, for example, len(mesh.vertices); If the model is first triangulated then this should write the final number of vertices after triangulation.
• Add a nice panel on the exporter's file properties that makes it easy to set up this header/footer and that makes it possible to include this info in export presets. Layout should be similar to the vertex format attribute list.
• This will allow basic support for BBMOD: at least BBMOD_Mesh and potentially BBMOD_Model
• It will likely also allow basic support for SMF (no animation)

Change file browser file filter when setting a different extension

With the new custom file extension setting it is now possible to export mesh data to file names with a different extension. This isn't reflected in the file filter.

Figure out a way to change the file filter upon changing the custom file extension export option.

Add the option to add an attribute to the vertex format for every element in a 'bpy_prop_collection'

A good example would be values of the vertex position and normal for the morph keys.
This is complex and likely requires an index into the collection.

Provide a default vertex format upon enabling Mesh Data export the first time

The 0 byte model files being exported can be confusing. These are created when the vertex format is empty. Either warn, prevent export or provide a default vertex format (passthrough) in this case.

Fix the plugin crashing for models that don't have a material or uv map assigned

The traversal of these members should improve but for now, just fix it

Automatically install export presets on install of the add-on

If you currently want to install export presets you first have to navigate to %APPDATA%\Blender Foundation\Blender\3.4\scripts\presets\operator\export_scene.gms_vtx_buffer, which means installing presets is something fully manual.

Ideally this works without any need for the user to navigate to that folder. Include some setting or button in the addon's preferences to enable a quick and easy installation to the included presets.

Support for primitive types other than triangle lists

This sure would be convenient

Support shader colours

Right now the viewport colour needs to be set, which is a bit cumbersome

Move conversion functions out of the global namespace into their own Python module

Rework completely for Blender 2.8 using packages

The existing Blender plugins have a nice file structure, using python packages.
With that, it appears that the nested class approach is not the right one.

Rework the code completely.

Examples can be found in obj, fbx, ... importers and exporters.

Blender 4 compatibility

Check if there have been any changes to Blender's bpy API and change what's needed/required.

Allow export window to display previous ".vbuff" export file names

Proper batching in files and directories + "append to file"

Dropdown menu for selection of conversion function

Blender 3.0 compatibility

Test this thoroughly

Put all functions and variables in ExportGMSVertexBuffer class

Use static and class methods

Allows easy cleanup and correct registration and unregistration of exporter class
Right now there are functions "floating around" in global scope that don't belong there

"Current" frame always exports the animation's start frame

Ideally selecting "Current" frame should export the frame that is currently active (bpy.context.scene.frame_current).
"All" should export all frames, either from the start frame or from the current frame (and then wrap from end frame to start frame). It could be an option whether to use the current frame or the start frame.

Proper axis conversion and use of orientation_helper

Change frame_option 'cur' to 'current'

Writing it out full is more intuitive in case you're calling the exporter through a Python script.

Add function set_format_from_type to make an educated guess about the type

no_verts_per_object should be defined in encompassing scope

Truncate return value of conversion function to format length

As an example, Material.diffuse_color has 4 components.
Drop the alpha component if format string is 'fff' or 'BBB'
Same for positions, keep (x, y) if format string is 'ff' or 'BB' or 'ii'.
Etc. etc.

The way it works now is not intuitive at all and also crashes the exporter.

No longer able to install add-on

Hey, I'm unable to install the add on to blender.
I'm in 3.2.1

Extend the signature of conversion functions with an additional parameter that allows access to all other properties

Support collection instances (recursively)

Add support for collection instances in the exporter, possibly as an export option. All meshlike items inside the collection instance should be added to the list of meshes to export and transformed if Apply Transforms is enabled.
This should make it substantially easier to export large world models that have collection instances in them. Important to treat every individual collection instance as a single entity (i.e. for purposes of batch export).