Neat! What a cool idea.
On Sat, Oct 31, 2009 at 5:27 PM, Tom Hawkins
Mecha is a little solid modeling language intended for machine design. Mecha has two layers: a pure functional layer for defining solids (aka. parts), and a monadic layer for arranging parts into assemblies. Solids (parts) are built using set operations on solid primitives. A solid primitives is simply a predicate that says whether a point in space is inside the solid:
data Solid = Solid (Vector -> Bool)
With a type like this, how is it possible to make solids without hard edges?
Mesh generation is performed by adaptive marching cubes.
It's slow, especially if you don't have graphics hardware. And solids with hard edges don't render very clean. But the basics work.
Here's a simple example:
example :: IO () example = view design
design :: Asm () design = do a <- part 1 0.06 8 $ difference sphereCube cyl3 b <- part 1 0.08 8 $ sphereCube c <- part 1.5 0.08 8 $ cyl3 color (0, 0, 0.8) $ place a move (-4, 0, 0) $ color (0.8, 0, 0) $ place b move ( 0, 4, 0) $ color (0, 0.8, 0) $ place c
Why did you choose a monadic interface? Is there a technical or semantic problem with a statement like: design = let a = part 1 0.06 8 $ difference sphereCube cyl3 b = part 1 0.08 8 $ sphereCube c = part 1.5 0.08 8 $ cyl3 in mconcat [ color (0, 0, 0.8) a , move (-4, 0, 0) . color (0.8, 0, 0) $ b , move (0, 4, 0) . color (0, 0.8, 0) $ b ] Luke