DI'ing marth's fthrow

[reverie2]

The way i understand trajectory DI is that you hold the stick +/- 90 degrees from the trajectory you are launched at, and it will influence the angle you are thrown by +/- 18 degrees.

When di'ing against marth's fthrow, if marth throws you forward to the right, wouldn't the possible di angles be anywhere from up on the control stick to down on the control stick (+90 degrees to -90 degrees assuming 0 degrees is directly right)? I'm watching this video https://www.youtube.com/watch?v=z9ybib14CkU&feature=youtu.be and they talk about di'ing in and di'ing out (which i'm assuming is hold control stick left and right), which doesn't make sense if you can only di +/- 90 degrees from 0. Where am i understanding incorrectly?

 

[Sycorax]

You can DI in any direction. All that matters is the magnitude of the displacement of the control stick along the axis perpendicular to the trajectory axis. For example, Marth's fthrow sends at 50 degrees. If you wanted to maximally influence the trajectory downwards to 32 degrees (=50-18), you would hold the control stick at the side of the gate at - 40 degrees, with 0 degrees being directly right. If you wanted to slightly influence your DI (i.e. slight DI), you have several options. You could hold the control stick to the side of the gate and place it anywhere between, but not including, -40 and 140 degrees. If placed it at 50 degrees, you will not influence your direction of travel. Another way would be to hold the control stick at -40 degrees, but instead of pressing it to the side of the gate, just hold it part way. You would tilt the control stick slightly like you would to perform a tilt+A attack.

What I said earlier about the range from -40 to 140 for slight DI is technically wrong. You actually get the same slight DI effect if your input is reflected across the axis perpendicular to the trajectory axis. For example, if you pressed the control stick next to the gate at 0 degrees (a 50 degree differential from the trajectory axis of Marth's fthrow), that would have the same affect as pressing the control stick next to the gate at -80 degrees, which also has a 50 degree differential from the trajectory axis. This picture might help you visualize the reflection symmetry.

 

[reverie2]

You can DI in any direction. All that matters is the magnitude of the displacement of the control stick along the axis perpendicular to the trajectory axis. For example, Marth's fthrow sends at 50 degrees. If you wanted to maximally influence the trajectory downwards to 32 degrees (=50-18), you would hold the control stick at the side of the gate at - 40 degrees, with 0 degrees being directly right. If you wanted to slightly influence your DI (i.e. slight DI), you have several options. You could hold the control stick to the side of the gate and place it anywhere between, but not including, -40 and 140 degrees. If placed it at 50 degrees, you will not influence your direction of travel. Another way would be to hold the control stick at -40 degrees, but instead of pressing it to the side of the gate, just hold it part way. You would tilt the control stick slightly like you would to perform a tilt+A attack.

What I said earlier about the range from -40 to 140 for slight DI is technically wrong. You actually get the same slight DI effect if your input is reflected across the axis perpendicular to the trajectory axis. For example, if you pressed the control stick next to the gate at 0 degrees (a 50 degree differential from the trajectory axis of Marth's fthrow), that would have the same affect as pressing the control stick next to the gate at -80 degrees, which also has a 50 degree differential from the trajectory axis. This picture might help you visualize the reflection symmetry.

Wow i had no idea Di worked this way. Do you have a source for this where i might be able to read more about it?Also you meant 40 degree differential from the trajectory axis right (not 50)? 50-90 = -40. the 0degree gate is 40 degrees away. -80 degree is also 40 degrees away. Also, when you say "gate" that's the equivalent of a notch on the controller shell right?

A followup question: if you were sent directly upwards (90degrees), would -90 degree DI have 0 effect on trajectory?If you reflect this across the perpendicular axis (the 0 degree axis), you'll get DI upwards, but DI upwards is the same direction you were sent, so that would result in no DI correct?

 

[Sycorax]

Wow i had no idea Di worked this way. Do you have a source for this where i might be able to read more about it?Also you meant 40 degree differential from the trajectory axis right (not 50)? 50-90 = -40. the 0degree gate is 40 degrees away. -80 degree is also 40 degrees away. Also, when you say "gate" that's the equivalent of a notch on the controller shell right?

A followup question: if you were sent directly upwards (90degrees), would -90 degree DI have 0 effect on trajectory?If you reflect this across the perpendicular axis (the 0 degree axis), you'll get DI upwards, but DI upwards is the same direction you were sent, so that would result in no DI correct?

You're not understanding it.

What I call the trajectory axis is the line that travels through the center of the circle at 50 degrees relative to 0 degrees which is directly right. It could also be thought of as 230 degrees (=50+180) of rotational symmetry. Either way the line deviates from a horizontal line by 50 degrees.

When I say gate, I mean the whole octagon that creates the bounds of movement for the control stick.

Perhaps this infographic will help you understand DI better. It's a little messy and in depth though :/

A followup question: if you were sent directly upwards (90degrees), would -90 degree DI have 0 effect on trajectory?If you reflect this across the perpendicular axis (the 0 degree axis), you'll get DI upwards, but DI upwards is the same direction you were sent, so that would result in no DI correct?

You are correct. Against a move that launches at 90 degrees, holding directly down in any amount (whether fully to the edge of the gate or just tilting slightly) will not influence your direction. This is because the magnitude of the displacement along the axis perpendicular to the launch trajectory (in this case a horizontal line, or 0 degrees), is zero. Your stick is not horizontally displaced. Any input horizontally will influence your trajectory proportional to how far it is displaced regardless of the vertical displacement of the stick. This is actually a good simple case to base your understanding off of. If you can understand how horizontal displacement is the sole thing that matters in the case of 90 degree launch trajectory, then you can just rotate your mental image of it to whatever other launch trajectory you want to think about.

 

[reverie2]

I think i get it now. 18sinx^2 basically clears it up. Do you have a link to a source on the formula?Also, tilting is the same as holding the control stick all the way right? Only the angle matters

 

[Sycorax]

I don't have any source on the formula except that infographic, but StrongBad is reliable.

Also, tilting is the same as holding the control stick all the way right? Only the angle matters

Actually, the angle does not matter at all. The only thing that matters is the distance of the control stick from the line along the launch trajectory. Tilting and holding the stick all the way will not have the same effect. Tilting will influence your trajectory less than holding it all the way. If the move sends at 90 degrees. Holding the stick at (0.5,0) will have less of an effect than holding it at (1,0). Holding this stick at (0.5,0) will have the same effect as holding the stick at (0.5,0.5) or (0.5,1) or (0.5,-0.25) or (0.5,y) where y is a number between -1 and 1. The game doesn't read values greater than 1 or less than -1 for control stick inputs.