Old console tennis game, what is the mechanism behind it?

Hi all,

Before using CF, im using AGK2 with initial intent to make a 2d tennis games but fail to dig out on how the mechanism of fake depth work and also its collision. So in AGK2, i am making 3d badminton game with 3d and pixel art texture. But now im have a wonderful 2d gamemaking tool(that is CF), i really want to learn how classic 2d tennis are made.

And so far, all i can assume is the fake depth can be simulate by using the slower Y coord. How about the skewed court?Is it still square grid?How about collision then? Refer pic attached from Sega Wimbledon.

Can someone give me ideas on hows thing working?

Thanks

Not sure what way you are going about doing this and how far you've got but, off the top of my head, I'd model the tennis game in an array and then just draw the graphical representation of the array separately. I'd need to think a little bit to give you the maths for how to draw it but it shouldn't be too taxing.

Edit:
Scrap that; that's stupid. Working through an entire array every frame just to find a single tennis ball is very inefficient. I'd have a tennis ball object with properties about it's position in 3-dimensional space and various other properties related to it's speed, direction, spin, etc. (depending on how complex you want to make it) and draw it every frame.

You could actually keep the collision simple and make a rectangular area (off screen) where you move your players, bounce your ball and do collision checks. Then use the positions of your ball and players and “translate” them into skewed screen coordinates. This is what you see in the end.

Is this the sort of pseudo-3D mechanics you're after?
https://www.youtube.com/watch?v=emaOMENzFRo

Check out Patrices example it might help https://community.clickteam.com/threads/98143-How-do-I-make-a-soccer-game-like?highlight=Ball

Quote:

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Originally Posted by mobichan

You could actually keep the collision simple and make a rectangular area (off screen) where you move your players, bounce your ball and do collision checks. Then use the positions of your ball and players and “translate” them into skewed screen coordinates. This is what you see in the end.

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Wow Thanks! Thats sound hard but shed some light. What u mean is a make an offscreen player and ball(say top down view)...and what the user see is just a translation in fake 3d world?

Yes. That is what I am saying exactly. :). Sort of like how most Mario Kart examples work. You have a sort of “ mini map” view where the actual game takes place. This is not shown to the player. Then translate the values into a skewed 3D view the player sees. I probably won’t have time to make an example for a day or two, but maybe someone else can code up an example sooner?

Another alternative would be to skew the screen with a shader or try the Mode7 object. But depending on which runtimes you want to support you might want to do this without fancy extensions.

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Originally Posted by Graeme2408

Is this the sort of pseudo-3D mechanics you're after?
https://www.youtube.com/watch?v=emaOMENzFRo

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Yes, it look like that but tricky part is volley movement:) Thanks

Quote:

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Originally Posted by aenever

Check out Patrices example it might help https://community.clickteam.com/threads/98143-How-do-I-make-a-soccer-game-like?highlight=Ball

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I give it a look :) Thanks

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Originally Posted by hoyoyo80

Yes, it look like that but tricky part is volley movement:) Thanks

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Use a variable to set the height of the ball. So a setting of 0 would be ground level, then say max height would be 10. Use the height to scale the size of the ball (gets bigger as it goes higher). Use an active to create a shadow - always set the ball to the position of it's shadow while height is 0. As height increases, off-set the ball vertically by a similar scale), e.g. for every increase in height by 1, off-set the y value of the ball by 5 pixels.
Depending on how you want your tennis game to play, to keep it simple you could have it so the ball always returns to height=0 by the time it reaches a player. Making so you can hit a ball on the volley is bit harder but could be done fairly easily by comparing the ball's height value to a height value assigned to the player's racket.

A game like Pong could translate to a tennis game quite well - with a bit of tweaking, using Graeme2408's suggestions here's a thrown together concept

Attachment 24394

Just something else you might want to consider when creating the skewed view is scaling. The top edge of the court (where the opponent facing you stands) is slightly narrower than the bottom (nearest) edge, e.g. 80% of the bottom edge. As the ball travels up (into) the screen it should gradually get smaller until it is the same scale as the top edge when it arrives there, i.e 80% of it's original size. By then it should also be moving 80% of it's original speed, otherwise the ball would appear to be speeding up as it reaches the far end of the court. The opponent at the far end of the court should also be scaled, so in this case 80% of the size of the player nearest to you, and move 80% of their original speed (since the court is 80% smaller at the top edge).
Hope I've explained this ok.

I think the easiest way to pull this off is the shader for skewed view as someone mentioned above. You might not be able to port it to other runtimes but if that's not an issue it would make things significantly easier. The mode7 object might be too skewed of a view, but maybe you can adjust that in the extension's settings, dunno I've never really used it. You'd also still have the portability issues with mode7 as well.

Quote:

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Originally Posted by aenever

A game like Pong could translate to a tennis game quite well - with a bit of tweaking, using Graeme2408's suggestions here's a thrown together concept

Attachment 24394

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OMG, with tweakSSS that is your game already:O

Thanks for the positivity hoyoyo80, I played with the above example and have created a pretty good tennis engine based of Pong. I'll post a clip here soon. Can anyone provide a basic example of how to use the perspective object to make the screen wider at the bottom and not so wide at the top?

I tried yet it only effected the top part of the screen.

Worked it out, The perspective object works nicely, yet it resizes what it overlays. Therefore the size of what you want to change the perspective of needs to be taken into account. I was getting a black area, or it would only change the perspective for the top part, turns out it's because the skewed image will take up a different size on screen. It's a lot of mucking around for an effect that doesn't change the game play, I'm not certain I'll bother?

Here's a video example of my progress. On the left is the game detectors and engine; and on the right is the game. Still a work in progress yet it works quite well so far.

https://www.youtube.com/watch?v=Lf2H...ature=youtu.be

it would be nice if you had even a few frames of shadow size changing to sell the visual of the ball bouncing. Also, ball size could change if there is an obvious lob. But it is looking pretty awesome overall. Can't wait to see how you add the perspective skew.