I just watched Gizmo's video on outline shaders with sprite stacking, but the terrain I want to outline is just made of polygons in the static buffer. Is there a clever way to achieve the outline effect using this method? 
I just watched Gizmo's video on outline shaders with sprite stacking, but the terrain I want to outline is just made of polygons in the static buffer. Is there a clever way to achieve the outline effect using this method?
I'm new to shaders so it'll just require some experimentation. After some looking on the GMS forums I found this tutorial, if anyone is interested: https://forum.gamemaker.io/index.php?threads/toon-and-outline-shaders.73138/
And hey Gizmo, thanks a lot for making these tools dude. Super intuitive and helping me learn 3D immensely. I'm gonna take a crack at your 3seqsD joint next
Awesome! Yeah that shader should work I believe. You will, however, have to implement your own things like lighting and such to work with that shader, since GM only lets you set 1 shader at a time, and the fauxton engines default shader is what handles things like lighting, so just keep that in mind. :)
Best of luck! :D