gamemaker-3d-io

A Blender addon which exports 3D models to a format that GameMaker Studio 2 will read natively.

This is a continuation of the GameMaker D3D and GML script addons for Blender 2.7x, recreated from the ground up to work with Blender 2.93. This version of the addon can export directly to a vertex buffer format that GameMaker Studio 2 will load/read natively, or to a GML script (mostly for debugging purposes) that can be put into a GameMaker project.

Not all of the options from the original plugin are present in this version, but most that were removed were superfluous and didn't need to be carried over.

This addon is a work-in-progress; thanks for your patience!

Features

• gamemaker-3d-io is an easy way to get objects from Blender to GameMaker Studio 2, using GameMaker's native buffer format
• Objects can alternatively be exported to a GML script for importing/debugging
• Exports models with normals, vertex colors, and UV coordinates included
• Exports models as triangle lists, line lists, or point lists

A number of example models have been included to try. The source code for this project is also available here.

How to install:

1. Download the Zip of the latest version of the addon from the download directory
2. Open Blender, then go to Edit > Preferences, and select the Addons tab on the left
3. Click Install... at the top right of the window, then find and select the downloaded Zip file
4. Check the box to the left of Import-Export: GameMaker Studio 2 3D format to enable the addon

How to use:

1. Create a 3D model for your game, then select it
2. Go to File > Export > GameMaker 3D (.buf, .gml), choose the desired options, and click Export
3. Depending on which output type was chosen:
   • For vertex buffers, load the file into a GameMaker project as a buffer, convert to a vertex buffer, and submit the buffer for drawing/shaders
   • For GML output, open the file, copy and paste the function into a GameMaker project, then call it in your game to build the model

Export Options

• Format: Choose to output the model as a Triangle List, a Line List, or a Point List. Line lists and point lists can only be a single color, and a new option to choose the color will appear if those formats are selected.
• Vertex Color: This option only appears if the output format is set to Line List or Point List. This color will determine the color the entire set of lines/points will draw when used in GameMaker.
• Use World Origin: If selected, the object's position will be applied before it is output, which will set the object's origin to the world origin. If unselected, the object will retain its original origin point.
• Flip On Y: Flips/mirrors the object's Y coordinates before it is output. This action will pivot around the object's origin, which will also be the world origin if Use World Origin is selected. This can help ensure that the object looks correct in GameMaker's 3D view.
• Flip UV Coordinates: Flips the object's UV coordinates (on Y), which can help ensure that textures draw properly once in GameMaker.
• Apply Modifiers: If selected, the object's modifiers will be applied to the model before it is output, which will make the output retain the same appearance as in Blender.
• Scale: Additional scaling to apply to the object before output, which can be useful if there is a disparity between your workspace in Blender and the size of objects in GameMaker. The minimum scale is 0.01.
• Type: Choose between vertex buffers or GML output. Vertex buffers are external files that can be loaded directly into GameMaker at runtime, while GML files should be copied into GameMaker as scripts/functions and used to build the vertex buffer at runtime. It is recommended to only use GML output for debugging, because the resulting scripts can be quite large.

Tips

• GameMaker requires a vertex format to use that when loading objects. The format for triangle lists is:

vertex_format_begin();
	vertex_format_add_position_3d();
	vertex_format_add_normal();
	vertex_format_add_color();
	vertex_format_add_texcoord();
format = vertex_format_end();

• The format for line lists and point lists is:

vertex_format_begin();
	vertex_format_add_position_3d();
	vertex_format_add_color();
format = vertex_format_end();

• If you output your object to GML, a copy of the formatting above is included in a comment at the head of the script.
• To ensure that objects retain smooth/hard edges in GameMaker, consider setting the object to smooth shading, then using an Edge Split modifier and marking sharp edges where desired. Make sure to export with modifiers applied.
• Legacy versions of the script, which supported D3D and GML output for GameMaker Studio 1, are available here: https://github.com/massivecatapult/gamemaker-3d-io/tree/main/legacy

Example

A pre-compiled GameMaker Studio 2 executable is available to try, which has a basic 3D world set up and some functions for loading and viewing models under different conditions. It can be found in the example directory. To try out the example for yourself, do the following:

1. Download the example from the link above
2. Extract the files to a folder and run 3D Model Viewer.exe
3. Use the following controls to view models (modeled after Blender's controls, for convenience):
   • Middle Mouse: rotate the view
   • Middle Mouse + Shift: pan the view
   • Middle Mouse + Ctrl/Mouse Wheel: zoom the view
   • Numpad 0: reset the position of the view
   • M: load a new model for viewing (you will be asked to confirm the model format after selecting a file)
   • D: set the model to "demo mode", which will have it rotate around all axis
   • L: toggle lighting
   • C: toggle culling
   • T: toggle texture
   • Escape: close the app

Roadmap

Plans for the continued development of this addon include:

• Ability to disable some types of data in the output, such as normals and UV data
• Additional options for viewing models in the example project, such as loading a custom preview texture
• Cleanup pass on code in example project (since this code was co-opted from another project, there's still a little cruft leftover)