3D Floor bug

[Eriance]

There is something wrong with the monsters when they try to walk onto a 3d Floor that is slightly lower than the floor they are one. The monsters that's on the higher floor can't walk onto the 3d Floor, even if it's 1 unit lower or heigher than the ground they are on. The Vise versa is also true when a ground monster tries to walk from a 3D floor onto a normal floor that is heigher or lower than it.

[Snarboo]

I'm not familiar with the Doom engine, but my guess is this is related to how the engine handles monsters' step size. Monsters will not walk over a wall if the distance to the next floor is greater than a certain value. This is why imps and other creatures don't usually walk over cliffs. The monster's AI is checking for the nearest floor height, comparing the distance to check and see if it can walk down to it, but skips over the 3D floor entirely.

Only Graf Zahl can say for sure. A simple test such as having 2 seperate steps 4 units heigh above the floor and a 2 unit thick 3D floor connecting both might prove if this is true. All monsters should walk down a 4 unit step.

[Phobus]

Same problem with Bridge things, and this is most likely down to something like the monsters height checks not including 3D floors or things, yet if there's no drop it detects, it can carry on.

[NeoHippo]

Possibly this is a related issue.
When monsters walk on a 3D slope, instead of their movement being fluid, they move in a dithering kind of fashion.
Sort of a rapid two steps forward and one back.

[Graf Zahl]

I believe this is the same as something I fixed recently.

[Tormentor667]

Still not fixed in the latest SVN build from Nash's site.

[Enjay]

It's certainly a lot better than it was. I have a 3D floor that is the same height as the normal sectors either side of it. With recent versions, monsters would refuse to walk on to it as if the line was flagged as monster blocking (it isn't). Monsters will now happily walk on and off this particular bridge. There were also a few WADs that I'd played where monsters placed on a 3D bridge refused to move off the bridge and these too are now fine.

I also have a set of stairs made from 3D floors. The steps 3D floors are 16 units tall and each step is 16 units above the next (so the top of one step is the same height as the bottom of the next). Monsters will happily walk down this set of steps but they do seem reluctant to climb them. I don't know what would happen with steps that were not quite as tall. Also, the underside of these steps is sloped which may, or may not, have an impact.

So, 3D floors that are flush with adjacent sectors seem fine but there may be a limitation of monsters not climbing up to a 3D floor that is higher than the floor next to it even though they do seem to go downwards.

[edit]
A bit more digging.

Monsters will happily walk on to and off of floors that same height as the adjacent one.

Monsters will happily walk down off a 3D floor towards a normal sector or another 3D floor. This includes walking down sloped 3D floors from flat ones. Normal drop-off heights seem to be respected - ie, they do not take a dive off a 3D floor much higher than the adjacent floor.

Monsters will not walk upwards to a 3D floor that is higher than the one they are on (even by 1 unit). This includes sloped 3D floors that are flush at the low end with an adjacent floor.