The very start of the full game TAS, nearly cutting the tram ride in half.

Steam version (uncapped FPS, capped bhop) with default server settings.

Detailed slowmotion video:    • Inbounds TAS slowmotion  


0:00 New game
Even if it's possible to get out of the tram during Black Mesa Inbound, almost the entirety of the events are still triggered as the func_tracktrain reaches its path_track waypoints.
1:15 Tram shortcut
The first two trigger_changelevels are supposed to be triggered by the player. The second one can be triggered before the tram gets there and as long as the tram ends up inside the world, it will check for the closest path_track and get to it straight through the wall and saving about 0,6s. this doesn't work at the first changelevel as the paths are placed more ambitiously.
However all the trigger_changelevels during BMI got the rare properties USE only flag unchecked. Meaning that even if they are placed 'out of reach' and supposed to be triggered only by the tram, they can still be triggered by player touch.
2:45 Leaving tram
I'm waiting for the tram to trigger the third changelevel as supposed. It will change level wherever the player is located. I use this to reposition myself to a spot where the maps are overlapping and end up at the end of the next map.
And it just so happens that the next trigger_changelevel is conveniently located in the ceiling where I end up. Making it possible to trigger yet another changelevel within frames.
After a precise drop down the hole I'm making a crouched edge bug on the rail to a standing landing on the ground to minimize the fall height. Then a 29fps frame just before reaching the ground to avoid the 6hp fall damage.
Since the pushables are in water/acid the game assumes the player is as well. Making it possible to use them even when not standing on the ground. So from the air I use it for 60 0ms frames to instantly achieve a max velocity boost on the XY axes.
Using the boosted speed to make a very precise slope launch into the next changelevel. It gotta be high enough to reach the trigger and too high would hit the ceiling making it hard to reach back to the catwalk.
A 4 fps frame is used to trigger barney 0,249s earlier. Another thing here is that if you don't trigger barney fast enough, he will start his scripted sequence towards the tram door instead.
Lowering fps again for barney to instantly face button and yet again to make the doors open 0,249s earlier.
As I slip into the door I use a 20fps frame to save 50 frames of ground friction, about 150ups and 0,09s.
Lastly using another 4 fps frame to trigger the changelevel sequence to c1a0. Lost a bit of speed due to ground friction during the frame but still saved about 0,2s.
Another note here is that I gotta save and load before the changelevel in order to make it possible. I'm guessing this is because I previously spawned inside a trigger_changelevel which makes the game lock the possibility of further changelevels to prevent a loop.



hltas script: https://pastebin.com/HYxm8GuJ

Half-Life TASing Introduction v2:    • Half-Life TASing Introduction v2  
Download Bunnymod XT: https://github.com/YaLTeR/BunnymodXT/...
Half-Life Physics Reference: https://www.jwchong.com/hl/

Unedited live captured footage of the hltas execution with bxt_hud_scale 2 using: https://github.com/YaLTeR/bxt-rs
A big thanks to ‪@YaLTeRz‬ for creating these tools and yuu for bxt_hud_entity_info improvement.



Map times from ordinary tramming, the 2014 segmented run and the TAS:
map tram seg TAS
c0a0 38.57 39.77 39.219
c0a0a 43.38 37.67 38.092
c0a0b 86.32 80.03 91.284
c0a0c 66.86 66.36 0.004
c0a0d 54.79 54.47 7.111
c0a0e 66.02 20.75 24.871
Tot. 5:56 4:59 3;20.581