I thought they had changed
maybe that was channeling
I am so confused
Yes, channelling is now "dig a down ramp", where you are channelling through more than the vestigial floor into an open area below.
I've previously asked for a "dig down ramp" (mostly for strip-mining reasons, where one doesn't want to accidentally undermine a tree or other potential cave-in item with an up-ramp request, to be honest) but I do rather miss the old channelling creating an unramped ditch.
Ramps themselves (once emplaced by either terrain generation or however they are dug out) are as yet unchanged. And the above idea seems to me to be a bit like a final "weathering" option on the map terrain generation.
A system that would not work well with the current game (both display and data structure), and goes quite a bit further than the "uneven" (you mean "odd number"?) and "even" level idea, is to have the 8 levels of tile filler (as representable by the one traditionally infinitesimally thick layer of floor, where present, and up to seven layers of fluid above it) be represented in finer detail would allow digging to be made (or simulated as) removing up to 8/8ths of any tile, (and each 1/8th directly to a unit of material, that needs spreading into adjacent tiles) and could be set to allow effective ramps of many different steepnesses. Single or double-eighths of difference between adjacent tiles would be hardly more than terrain undulations (though enough to cause rain to pool, and one could imagine dynamic weathering and erosion occurring during the rain that comes during game-play, and possibly the footsteps of dwarfs over well-travelled routes that currently 'ensoil' grasslands, as well as allowing snow-drifting behaviour in hollows and against walls, if one wanted to complicate such things), with around 4/8ths difference (within or between adjacent Z-levels) being counted as a standard traversable ramp for hauled wagons (of two beasts or more?) or pack animals without some sort of [SUREFOOT] tag in their raw and 6/8ths being walkable (with load) by bipeds and [SUREFOOT]s while 8/8ths traversable by bipeds without anything hauled (or maybe at least one hand free of weapon/tool/shield, which might bring in a requirement for scabbards, belt loops, etc being craft items), or [MOUNTAINSUREFOOT] creatures. Any difference that meant a >8/8ths total difference being a cliff would require specific climbing equipment (TBA, though maybe related to Toady's idea of a rope for stairless downwards travel) or whatever tags GCSs and the like would display, or of course flight. All those values being open to adjustment based on the creature involved, inherent climbing abilities and possibly the material of the 'wall' involved[0].
When it comes to river-edge squares, any eighths of water are assessed as a rounded down half value, to account for buoyancy, maybe (although this might or might not take into account the weight and/or overall density of worn equipment[1]) so that a puddle at the bottom of a pit doesn't let one escape, but it being totally full gives one a distinct help. (May mean a redesign of moat-strategies, but not much more that already done between 40D and now.) You could even translate that to magma (cut down even more, with even more buoyancy ), for those creatures where that doesn't already induce death in itself...
But that's a speculative idea based on some (long-term, if ever) suggestions already previously made, not a suggestion in its own right.
- It would be arguable whether raw soil is easier that rock or harder, because it having less structural strength could work either way on whether hand-holds could be made. Might need more complexity. But I sort of envisage built stone block walls as more unclimbable than those made of unprocessed stone rubble that leaves plenty of footholds, and smoothed natural stone walls (in certain types of rock) being pretty much unclimable by all creatures without some inherent wall-climbing/ceiling-traversal nature.
[1] And anything that could not dropped and abandoned. Maybe with agent logic so that they might drop a sword to escape a flooded square, to remove a backpack to allow them to re-enter the square to
try to reclaim the sword and get back on the bank to re-equip... But that leads to complex fording behaviour where a unit might make multiple trips across a watercourse to get themselves and all their armour/weapons across... Sounds too complex for the current incarnation, though in Adventure Mode it might be a valid player strategy if weight of equipment starts to matter so much in swimming and general river-extrication....