Earlier this month, Tyler Kehne announced he was theorizing a new “godlike wall clip tech.” If it works out, it could allow Mario to pass through a seam between two walls under very precise conditions. Here’s how Tyler explained quantum tunneling:
Basically, due to floating point rounding error in the wall collision calculations, it’s sometimes possible for a very small gap to exist on the seam between two wall triangles.
Unlike a misalignment where an opening exists because walls don’t match up, quantum tunneling would create gaps where wall seams are mathematically identical. Tyler, bad_boot, and Ystem made programs to brute force for these floating point oddities. Initially, their programs found many wall overlaps, but no gaps. Finally, they found some quantum tunneling gaps, including this one below the TTC entrance that Tyler posted on YouTube.
These gaps are so incredibly precise that Tyler had to hack Mario’s position to get in one, but pannenkoek2012 developed a brute forcer to tunnel through the TTC gap organically, and rcombs verified the technique works on original hardware.
Tyler first dreamt up quantum tunneling as an idea to get past the SSL elevator with no A presses for the A Button Challenge. Although no quantum tunneling spots have been found on the elevator, a gap in the right place could allow Mario to go straight through a wall, land on a platform higher than he can normally reach, or do a glitchy ledge grab in places where he couldn’t before. It remains to be seen what quantum tunneling will contribute to the A Button Challenge and speed TASing.
Finally, for those more technically inclined, I asked Tyler how quantum tunneling works. Here’s his explanation:
To calculate whether a point is inside a 2D triangle, the game checks to see if it is inside each edge of the triangle. It does this by comparing the slope of the edge to the slope of the point and one of the vertices on the edge.
In this image, the slope of line 12 is compared to the slope of line 1P, the slope of line 23 is compared to the slope of line 2P, and the slope of line 31 is compared to the slope of the line 3P. The direction of the inequality, as well as whether the vertices are ordered clockwise or counterclockwise determines if the point is “inside” the line. Only if it’s inside all 3 lines is the point inside the triangle. This method works really well, unless the point is right at the edge of the line. In that case floating point rounding error can give an incorrect inequality. For this reason, if you have two triangles that share an edge, sometimes a point on the edge will fail to be calculated as inside either triangle. We call this a wall gap, and it’s possible to tunnel through it with precise movement. The gap extends through the entire wall hitbox at the same coordinates, because wall hitboxes are basically 2D.
It’s also possible for a point on the edge to be calculated as inside both triangles. In this case, the push from the wall at that point is doubled. We call these wall overlaps, and they’re much, much more common than gaps. We don’t fully understand why, but we’re pretty sure that it’s partly because if the slopes are exactly equal, the point is an overlap (i.e., overlap is the “tiebreaker”).
In Other News
- akki941 broke the RTA 16 Star WR with a time of 15:08 a day after Drozdowsky set a 15:16 WR to beat akki’s previous WR. A link to akki’s run can be found here. A link to Drozdowsky’s run can be found here.
- At GDQx Mario 64 made two appearances- once in a commentated 1 Key TAS commentary by cheese05, and once in a 120 Run also by cheese05. Great job to cheese at the event!
- pannenkoek2012 showed a method to move the BoB stationary Bob-omb to an arbitrary location. This is achieved through the usage of multiple instant releases. The video can be found here.
- ALX167 published a TAS of Eddio0141’s “Glitchy Mario 64” ROM hack that removes all speed caps from the game. Alex beat the hack in 3:59.85, improving Zombie’s previous time of 4:22.75. ALX167’s TAS can be found here.
- Taggo finished a 70 star run in 47:46, which was the second fastest run of all time. The WR and previous second place are both runs by cheese05, with times of 47:43 and 47:56 respectively.
- cheese05 won the GSA 120 Star invitational! puncayshun took second place, and Dwhatever took third.
- ProjectRevoTPP discovered that the Koopa wearing pink underwear when outside of his shell is caused by a malformed light entity and was seemingly originally unintentional. It’s possible the developers made an active decision to keep this once they saw the bug, but it is not possible to know their original reasoning.
- Nonstop Mario 64 had multiple new runs this week. lunarjump claimed a new WR in 70 star nonstop with a time of 30:14. This record wouldn’t stand for long, though, as TriforceTK finished a three PB week with the first sub 30-minute run (29:53). Additionally, Sigotu took third place in 70 star nonstop and SoloQ took second place in 16 star nonstop.