react = Tool-Assisted Speedruns (TAS) are created by using emulators to play games frame-by-frame, allowing for, 100% accurate inputs, extensive save-state usage, and re-recording to achieve theoretical perfection. Creators use tools like BizHawk or Dolphin to slow down gameplay, optimize, and manipulate game memory (RAM) over weeks or months.
en.wikipedia.org
they can react instantly as they run game frame by frame. They aren't playing the game as such
what you saw could have taken months to create.
Often TAS find things actual speedrunners later do.
Google AI offers this for loading screens in HL and TAS:
Here is how loading screens are managed or removed in Half-Life TAS:
- Software Mode (GoldSrc/HL1): Running the original Half-Life in Software Video Mode can remove the visual "loading..." text, making transitions look like brief, instant stutters rather than full-screen pauses.
- SSD and Fast Hardware: Using a fast NVMe SSD largely mitigates loading screens to sub-one-second times, making them functionally nonexistent.
- Engine-Level Map Merging (Mods/Custom Builds): In special cases like Sven Co-op, map geometry is merged, removing loading screens between areas. However, in vanilla HL1, this is not possible without breaking the game engine.
- TAS Frame Data Manipulation: In TAS, loading screens can be bypassed in video records by deleting the frames that contain the load screen image and re-syncing the movement, effectively editing them out of the final video.
- cl_showloadingscreen 0: In some Source engine games, using this console command may hide the loading graphic, though it does not eliminate the pause in gameplay.