Hacky multi-Z implementation issue tracker

[TheArturZh]

Mission impossible make moony's april fools joke playable

Current bugs in local repo

• Fix mapinit working weirdly with zlevels
• Fix weird client crash when going back up from broken level
• Fix lowest viewport still rendering when on lowest level (double render)
• Fix crash when rejoining the game with actor on multi-z map
• Z view OnCompShutdown crash ("Collection was modified")

Required upstream changes

• Fix VSync halving the FPS
• Find a way to optimize renderer for multiple viewports/big amount of entities

Edgecases and shit

• Make falling predicted and make it trigger when parent changes so server doesn't die
  • Ensure gravity is not toggleable for multi-z constructions (override gravity generator behavior)
• When pulled object falls down it starts glitching. System should either break pull or prevent falling.
• Falling should shift object in a direction of movement to prevent wall clip (if it will not work well then just snap em to a tile as a lazy fix)
• Random rotation and position should be handled properly for multi-z stations
• Grabbed object should also teleport when player traverses via ladder or stairs. It should take the same position as the character. It however shouldn't be done when just falling.
• Automatically disable split checks for multi-z constructions (Nope I'm not dealing with that)
• Walls should create indestructable tiles on upper levels when anchored and restore original tiles when removed/unanchored. This is needed to prevent players from falling through walls.

Improvements and features

• Falling should stun player
• Damage should be mainly directed at legs (whenever NewMed is merged)
• Add multi-entity stairs - one denies fall damage, other pushes you up
• Implement batch map loading & linking (multi-level stations) - via staiton proto mb?
• Add cross-map substepped spring joint
  • All grids in the stack should be linked to a single grid for better stability, and substepped at the same time
• Add solid vertical cables and pipes that occupy entire tile
• Multi-Z Atmos (oh god oh fuck)
  • Need a quick cross-level gas traversal check - perhaps a separate ceiling/floor map, because I'll also need fake ceilings/floors
  • Multi-Z atmos mode should only work for multi-z constructions
• Make mass scanners display all layers for multi-z maps
• add ceiling overlay for topmost layer in a construction so shuttles don't look stupid
• multi-z FTL (necessary for sierra)

[TheArturZh]

Need to check if setting SpriteComponent.Visible every frame can cause major performance issues
If not, I can try to generate low-res visibility mask by sampling tiles of grids within screen bounds and use it to hide some of the entities. Additionally I can sample viewport texture / light buffer, assuming that RGB 0,0,0 is FOV.
that was a bad idea