Game Maker - Improved 3D Terrain Editor

Fall 2019: This is better than the original but it's still got some problems. I've got a third - and hopefully final - terrain editor here.

About a year ago I published this thing, which is essentially a heightmap terrain editor for 3D projects in Game Maker. Over the last few months I've been working on a better version, something that's easier to use and has an actual GUI so you don't have to control literally everything through the Function keys.

Stuff you can do:

• Create bumps in 3D terrain by clicking on it.
• Texture terrain by clicking on it.
• Paint terrain by clicking on it (this includes transparency, but why you would ever need this I have no idea).
• Save and load projects.
• Export Game Maker model files (*.d3d).
• Some other stuff, I guess.
• If this takes off I may add more features, it depends on how lazy I am.

Notes:

• This was made in Game Maker Studio and should work on any modern computer but older ones might experience some slowdown while in use. One free gigabyte of RAM and a display of at least 1440x900 (odd, I know) is strongly recommended.
• It's possible to create some truly gargantuan maps using this program. Anything with more than 32,000 faces (96,000 vertices) won't load in Model Creator. Anything that's too big may or may not work in other applications either, but they should work in Game Maker.
• If you're using the models in Game Maker 8.1 or previous versions you may have to get rid of the whitespace in the file before you use it. Open it in Notepad or Notepad++ and do a global find-and-replace. This also goes for Model Creator for Game Maker, as it was made in Game Maker 7. Or 8. I forget.
• It's 2018. Please do not do 3D stuff in Game Maker 8.1.
• The icon is a paw print. No, I don't have a good reason for this.
• The technical implementation is up to you! This tool facilitates the crafting of 3D terrain for Game Maker but ultimately you have to know what to do with it.

If you don't use Game Maker but think this is sort of cool-ish, Model Creator for Game Maker has an option to convert from d3d to obj (that may or may not actually work as intended).