implicit VS gloss

There's also ImplicitCAD (https://github.com/Haskell-Things/ImplicitCAD) which produces STLs, as it is designed for CAD. It uses implicit functions, which I believe are similar to SDFs (I believe the idea is not to necessarily correspond to the distance function).

ImplicitCAD is essentially OpenSCAD with bevels.

You might take a look at ImplicitCAD. It accepts OpenSCAD code (as well as some other more exotic formats) and can render much much faster depending on resolution. There's an online editor/renderer here that would tell you whether it can handle your existing code unmodified.

That Picture type is what does all the heavy lifting. Have you read its Haddocks already? There's an example using play in gloss-examples if it helps you (it just renders the most recent event as text on the screen). When I was new to Haskell and gloss, I found "following the types" helped. There's only a limited amount of things you can do with Picture, and those limitations can help guide you.

Haskell is the purest of the pure, and a fun language. Never done graphics with it but I see Gloss looks decent - https://github.com/benl23x5/gloss.

If you just want to draw stuff on a window, then have a look at gloss (a very simple yet useful interface to OpenGL) and sdl2 (which gives bindings to the SDL library).

This question is in the gloss FAQ:

Ideally, I'd like something like gloss in Haskell.