Sonic's Homing Attack under the stage

[T-block]

I spent some time today testing out the behaviour of Sonic's Homing Attack when used under the stage in light of recent discussion in the Unity Ruleset Discussion thread.

When Sonic uses his HA below a solid stage, close to the ceiling, he collides with the stage on release and can HA again before falling too low, resulting in an "infinite" stall. However, after colliding with the stage, Sonic will sometimes move to the left or right (up to 1/5 of Battlefield, approximately) or may stay in the same place.

It seems like the direction he moves is strongly correlated to the position of his opponent on-stage. When the opponent is to the left of Sonic, he tends to move to the left, and when the opponent is to the right, he tends to move to the right.

There are a couple of problems with this description though. The behaviour is only predictable when the opponent is horizontally a good distance away from Sonic's position. Once the opponent comes close (but still clearly to one side), his movement is no longer guaranteed. The other problem is that this seems to describe behaviour on BF and PS1 fairly well. However, on Final Destination, even when the opponent is on the left side of the stage, I've seen Sonic pop to the right. Movement on Final Destination seems fairly random (although a slight correlation can still be seen).

Questions:
What makes Final Destination so special? Does stage geography have anything to do with it?
On what stages is his movement predictable? Some to test include Smashville, Lylat Cruise, Frigate Orpheon...
Which player does he track when there are more than two players in the game?

Anyone have any insights to offer?

 

[Sieguest]

Questions:
What makes Final Destination so special? Does stage geography have anything to do with it?

That's what I was thinking. What also comes to mind is that when a character is too far away for homing attack to recognize as a target, that Sonic may just end up moving in the direction is body is facing.

On what stages is his movement predictable? Some to test include Smashville, Lylat Cruise, Frigate Orpheon...

Unsure... I do know that Sonic tends to move along inclines if you do it there. Examples being the lips of FD and the rises on the sides of BF.

Which player does he track when there are more than two players in the game?

He'll track the closest player that does not have invincibility frames whenever the move comes out.

Anyone have any insights to offer?

One final edit: I kind of think of Sonic's homing attack as if I were throwing a tennis ball at someone or something. What would a tennis ball do when it hits X surface at Y angle. Usually Sonic follows suit.

 

[Kinzer]

If it's any consolidation, it can also vary depending on which way Sonic is facing when he starts Homing Attack.

The only thing I'm still not sure about all this is whether or not Sonic has an increased tracking range when an opponent is laterally in front of him or if it's the same all around and within his tracking range. Simply going to test this in the game though could confirm it though.

 

[Toomai]

The only thing I'm still not sure about all this is whether or not Sonic has an increased tracking range when an opponent is laterally in front of him or if it's the same all around and within his tracking range. Simply going to test this in the game though could confirm it though.

I don't have an image to draw on to explain this better, but I'll give it a try: During the startup of Homing Attack, there is a very large inert hitbox, 75 units in radius. By comparision, Sonic curled up is about 4.75 units in radius - assuming the inert hitbox is the detector, it's almost 16 times as big as Sonic is. The center of the inert hitbox is shifted 10 units up and 10 units forwards (slightly more than one curled-up Sonic width), so there's a bit more range above and in front.

 

[DeLux]

Can we get expidited conclusive testing on this? It's vital to the BBR-RC apparently.

Seems like it's a project that has "Toomai" written all over it

 

[T-block]

Looking forward to hearing your elaboration, Toomai. This sounds super interesting o.o

 

[Kinzer]

I don't have an image to draw on to explain this better, but I'll give it a try: During the startup of Homing Attack, there is a very large inert hitbox, 75 units in radius. By comparision, Sonic curled up is about 4.75 units in radius - assuming the inert hitbox is the detector, it's almost 16 times as big as Sonic is. The center of the inert hitbox is shifted 10 units up and 10 units forwards (slightly more than one curled-up Sonic width), so there's a bit more range above and in front.

Ah thanks. I figured it was but I wasn't sure, so I didn't want to say this or that and end up being wrong in the future... especially not about my own character. X_x

 

[Toomai]

Here are some more numbers:

Homing Attack's detector radius is 75; its diameter is 150.

Battlefield is approximately 156.5 units long (I don't yet know how to get exact distance numbers out of stage data). Most of its underside is flat, while there are a few apparent 45-degree slopes around the center (which is also flat on the bottom of the pointy bit).

Smashville's main platform is about 140 units long, but with the moving platform it's easier to get out of the detector's range. Its underside looks pretty much flat.

Final Destination is almost 174 units long. Its underside is not flat at all; it's concave. This would explain why it acts differently than the above two.

Now maybe one of you people can turn this into something actually useful, because I don't know where to go from here.

 

[rPSIvysaur]

I think the bigger question is whether or not he's able to control where's he headed so that way he can stall indefinitely, or if the opponent can lure him out.

 

[DeLux]

If the detection is 75 units, that would have to mean that you could draw them out if you moved with in 75 units of them. By say, dropping off the ledge within 75 units of Sonic, and then the homing attack would lock on in that specific direction.

No?

 

[T-block]

Stage geography does have something to do with it then.

So the detection area is a perfect circle? But Sonic isn't in the centre, right? The centre is slightly above and in front of him?

Possible FD explanation: Sonic will still follow his opponent, but during my tests the opponent got out of range, so the attack didn't home in on him? What is the behaviour when it has nobody to lock onto? Does it apply to invincibility too?

 

[Toomai]

I decided to draw a picture:

Blue is Sonic (facing right). Grey is the detection range. Yellow is Smashville, green is Battlefield, cyan is Final Destination. Stage thickess is not to scale; everything else is.

 

[DeLux]

Camera Center (x,y) (0, 0)
Top-left Camera Limit (x,y) (-170, 130)
Bottom-right Camera Limit (x,y) (170, -50)
Top-left Blastzone (x,y) (-230, 180)
Bottom-right Blastzone (x,y) (230, -115)
Respawn Platform (x,y) (0, 70)
Main Platform Height (y) (.2)
Other Platform Heights (y) (24.375, 47.375)
Main Platform Width (-x, x) (-78.116, 78.043)

Battlefield Stage Data

So by jumping above the camera line, one would move out of range no?
Or are those units not the same?

 

[Sieguest]

If the detection is 75 units, that would have to mean that you could draw them out if you moved with in 75 units of them. By say, dropping off the ledge within 75 units of Sonic, and then the homing attack would lock on in that specific direction.

No?

I don't think so and here's why... When Sonic finally moves to attack an opponent the hitbox is already against the ceiling(underside of the stage), so he'll just rebound as soon as the hitbox is active. This backed up by the idea that sonic moves diagonally downward in the direction he is facing when no one is in the tracking range and yet still manages to rebound off of the ceiling.

Possible FD explanation: Sonic will still follow his opponent, but during my tests the opponent got out of range, so the attack didn't home in on him? What is the behaviour when it has nobody to lock onto? Does it apply to invincibility too?

When there is nobody to lock onto Sonic moves according to the stage contours from what I've seen. Like if you HA under a ceiling that slopes like this: \ Sonic will move left. If it's something like this: / then sonic moves right. Kind of like I said earlier about throwing a tennis ball straight up into a ceiling. (The only difference being Sonic will always move up and not back down like a tennis ball would. >.<)

The move follows the same behavior with characters that have invincibility as those that are outside of the homing range.