Ask the Developer Vol. 5, Nintendo Switch Sports - Part 2

• Content pre-recorded in accordance with current COVID-19 health and safety guidelines.

• This article is translated from the original Japanese content.

• This interview was conducted before the game came out.

1:Striving for a movement-based game that is the easiest to invite in the world

4:Playing with others is fun in itself

You mentioned earlier that it was not easy to implement on the Nintendo Switch system what was achieved on the Wii system. So, I would like to ask the developer Okane-san, what exactly are the differences between the Wii system and the Nintendo Switch system?

okane: First of all, Vii Sports used Vii Remote ™ (4) as a controller, and we built it into the game while we were thinking about what playing could be done with Wii Remote. But with the Nintendo Switch system, it was the opposite. In the beginning, the idea of ​​rocking was already decided and we had to figure out how to implement this idea with the Joi-Con controller. As a developer, this required a lot of trial and error.

(4) Primary controller designed for the Vii home game console, released in 2006. This controller has a vertical shape, similar to that of a TV remote control, and is designed to provide intuitive and easy-to-understand operation at a time when Nintendo aimed to expand the population games.

To the untrained eye, you would think that this can be easily achieved, since you swing both the Wii Remote and Joi-Con controllers, and they should contain a sensor for that purpose …

okane: If you hold the Vii remote control, it has a certain weight and size. When players play tennis or bowling with this weight, it allows them to control the Wii remote control naturally with the right amount of momentum to play. So it was easy to assume how players would hold and swing it, and as a programmer it was relatively easy to figure out how to swing. But the Joi-Con controller for the Nintendo Switch is much smaller than the Wii remote control. So, it differs a lot from person to person in the way they hold and move it.

Of course, when the controllers are smaller, it is easier to swing your arms freely, and I understand that they can swing in many different directions. But how does that actually affect the game development process?

okane: It is difficult to apply motion detection: “if it swings like this, it should react like this”, in a way that satisfies the players.

In a way that satisfies the players? Does that mean making sure things like, “I thought I swung, but it’s not recognized,” won’t happen?

okane: Yes. Also things like, “I thought I swung left, but it went right.” As we progressed, we were able to apply detection so that about 80 to 90% of the time we reacted as expected, at an early stage. However, applying the top coat to the movement controls so that they feel natural and completely satisfying when using them is very difficult. Both Shimamura-san and Yamashita-san mentioned earlier “how they aim for a movement-based game that is the easiest to call in the world.” To achieve this, it is crucial to work on detecting over 90%.

What do you think of this, Yamashita-san? Did you feel that you could achieve adjustments “above 90%”?

Yamashita: Well, it was harder than I thought. That’s because when we actually made the game and played it with a group of people who played the previous series, they could play it without too many problems. However, when we invited someone who had never played this game before to try it, the ball did not fly in the direction they expected. I can understand “the procedure is different” or “the momentum is different”, but there were moments when people said things like: “This is not how you move in real sports!” …

Not how you move in real sports? What it means?

Yamashita: Take, for example, volleyball. In real volleyball, you don’t move your arms and wrists when you hit each other. When in the striking position, the player keeps his hands in a fixed position and returns the ball, using his knees to break through. This is the official way of hitting volleyball.

Yamashita: But if you’ve never played volleyball before, you’d think of throwing a ball in the air swinging your arms and arms up, wouldn’t you? However, the programmer in charge of volleyball development was an experienced volleyball player. So, the developer had an “official strike” move needed in the game as well. When we tested the prototype with everyone, as expected, everyone raised their hands holding Joi-Con to hit the ball. Surprisingly, even those with volleyball experience made the same move. But the program is designed on the premise of “keep your hands still”, so that the ball would fly in the wrong direction. In other words, the programmer, who was an experienced volleyball player, made a game mechanic where the player had to keep his hands still, adjust the angle and hit …

Sounds like it’s hard to control if you don’t know how to play.

Yamashita: That’s right. It’s fun when you know how to play that game. “Oh, so authentic! This is like volleyball! ” But when we tried it together without any explanation, almost everyone raised their hands. We all thought, “What are we going to do with this !?” So, we come to the part where we think this is going to be a mechanic. But then the main programmer, who has real volleyball experience, will worry that volleyball could be lost.

But even when people with real volleyball experience played, they still waved their hands up, right?

Yamashita: Yes they are. With that in mind, the only way to make a game that people who know nothing about it can naturally play with a quick glance is to make it a game where players still wave their hands to hit. … And so, after some discussions, all the methods for identifying the movement were reworked.

Whether it’s a real move or not, it’s really easier to understand if the ball is flying in the direction you expect.

okane: If you need to play long and thoroughly, it can be an option to do it in an authentic and correct volleyball form. However, I felt that it would be difficult to convey the fun of the game in a short period of time, while at the same time the player should carefully read the instructions for work during the game.

Are such adjustments only in volleyball? Were there any adjustments in other sports?

Yamashita: There were fewer sports that actually went smoothly. (Laughter) In the planning phase, there were already some kinds of adjustments necessary for all sports. For example, badminton. The look is similar to tennis from previous games in the series. At that time, in tennis, the direction of the return of the ball was determined by the time of the swing. If you swung at an earlier timing, the ball would fly to the left, and if you swung at a later timing, you could hit the ball to the right.

If you try to bring that same concept into badminton, and ask someone who doesn’t know the premise of playing, he might say, “I don’t know why the swing time changes the direction the ball flies!” Shimamura-san and I know that it is not the direction of the swing but the timing of the swing that determines the direction in which the ball (feather) flies, since we know the method from the previous titles. But those who have played without knowing this premise will say that it is simply not right.

Wasn’t it possible to recognize the direction in which the Joi-Con controller is swinging in tennis and, based on that recognition, to determine the direction in which the ball was hit?

Yamashita: When you really play it, that method is very difficult. When we try to figure out the direction of the swing and use it to determine the direction in which the ball is flying, it makes the commands unstable and the ball not flying in the direction you expect. Even when Vii Sports i Vii Sports Resort as they developed, the developers told me, “Please don’t do that.” However, there were suggestions from staff members who were unfamiliar with the trial and error process at the time that they said, “We want to recognize the direction in which the ball flies in the direction of the swing ‘.

okane: I understand that badminton is a sport in which the ball will fly in the direction in which you swing. I knew it was going to be hard because it had already been experimented with over and over again earlier in the series.

Yamashita: As a director who has experience working on previous titles, asking them to achieve that when you know it’s technically difficult was tantamount to “losing.” So the director has to solve the problem with ideas on how to make movement controls natural, not through technology. I said, “That’s what directors do!” But in the end, I made them solve it with technology. However, there was no chance that it would be so easy.

In this title, how did you overcome what seemed technically impossible at the time?

okane: We have made many attempts and mistakes. In terms of new technology, we tried deep learning (5), which was not available when Vii Sports has been developed.

okane: For example, we asked various people to “swing as if you were striking to the left” and “now swing as if to strike to the right”, and we repeated the process over and over again to get a large amount of data. It is a technology that detects whether a player is trying to hit the ball to the right (or left) by statistical analysis of the obtained data. So by incorporating such technology and experimenting with this and that, we tried to bring it to a level that everyone could agree on.

(5) Machine learning technology captures large amounts of data, such as images and video, into computers and analyzes data characteristics.

Yamashita-san mentioned earlier that it is very difficult, but Okane-san, how do you feel about the direction of the swing that determines the direction of the ball?

okane: I thought it was going to be hard. Deep learning is great technology, but it is not magic. If we can get enough data “from the beginning of the swing to the end of the swing”, we may be able to estimate the exact direction. But if the ball reacts and takes off after the player has finished swinging, the players would feel unresponsive and one step behind. So, if we try to use the data just before the end of the swing, the exact movement cannot be estimated because there will not be enough data this time. In other words, there is a trade-off between targeting “accurate detection” and “satisfactory response as movement control.” So, we made adjustments over and over again, persistently saying things like, “I think he’s here somewhere! … No, maybe he’s here somewhere!”

But with the accumulation of these constant efforts, the 80-90% you mentioned earlier came close to 100%, right?

okane: Yes, so I would say that we could achieve about 90 to 95% detection quite smoothly. But the last few estimates have been really difficult … For example, when a player serves in badminton, and even if the ball flies as expected nine out of 10 times, if the player misses even once, he will think: “Um, it’s hard to control … ”So, although it is impossible to reach 100%, it is very important to work on this last small percentage, even a small one. This is no longer something that can be solved with the latest technology, so we all worked hard by involving as many people as possible and making detailed adjustments.

Shimamura: Every day we would hit 200 times to the right, left and center to see how the latest settings work. My right arm was so inflated and cancer-like. (laughter)

I guess the development of a movement-based game is difficult when it comes to testing …

Yamashita: It’s a sequel to previous games in the series and also a motion-based game, but as explained, it can’t just be a simple port. I think that all sports were close to being rebuilt from the ground up in a way that was adapted to the Nintendo Switch system.

Read more - Part 3: Sense of continuity