Slope editor

[eevee]

For reference, an exhaustive list of slope mechanisms:

• Plane_Align — use sector heights only, can already be edited in 3D mode
• Plane_Copy — nothing to reasonably edit
• Vavoom slope things — use sector height + thing height, can be edited in 3D mode with #393
• Vertex height things — use thing height, can be edited in 3D mode with #393
• Vertex height UDMF props — buggy due to #386, would need visible vertices in 3D mode for live editing
• Line slope things — use sector height + thing height, can be edited in 3D mode with #393
• Sector tilt things — use sector height + thing height + thing angle + arg0, can be partially edited in 3D mode with #393, would need special handling for the angle and argument
• Slope copy things — nothing to reasonably edit
• UDMF plane props — absolutely hostile to human beings, not supported at all (#388), would definitely need dedicated UI

We're doing pretty well so far — with #393, you can edit most of these entirely in 3D mode, once you've set up the specials and whatnot. Only three standouts.

UDMF vertex heights would need vertices to be visible in 3D mode. Maybe only for triangular sectors, and only when aiming at/near them? Then you could select them and raise/lower with the mouse wheel, which would be pretty cool. You could make complex geometry just by making a big mess of triangles and playing around in 3D.

Sector tilt things are a bit awkward. I don't know how you'd change a thing's angle in 3D, and I especially don't know how you'd change a "tilt" argument in 3D. But these are also really useful and flexible if you're not using UDMF, so the effort might be worth it.

UDMF plane props are the easiest for an editor to work with and probably what a 2D slope editor would work with. I've seen a video of GZDB editing slopes in 2D, using a segment across the sector like gradient editors in some graphics programs. No idea what height the endpoints of the segment were supposed to be, or what it would look like if you opened an existing map with slopes.

Might be a good idea for 3D mode to show why a given sector is sloped, if you've lost track. I can imagine being very confused if the mousewheel doesn't work on a flat sector because it's technically sloped by UDMF properties, for example.

[zgramps]

UDMF vertex heights would need vertices to be visible in 3D mode. Maybe only for triangular sectors, and only when aiming at/near them?

This would be great.

Then you could select them and raise/lower with the mouse wheel, which would be pretty cool.

Was just wondering if it would make sense to stick a transient fake thing there that can be manipulated just like a vertex height thing, except it's backed by that UDMF field instead of being an actual thing. The fake-things would only appear when aiming at/near a triangular sector.

Sorry about bumping an old ticket, but this still seemed relevant...