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Member Since 22 Mar 2012
Offline Last Active Feb 26 2016 06:40 AM

#5058342 My approach to physics

Posted by on 01 May 2013 - 11:24 AM

Physics is hard. [...] Your paper (and physics texts generally) live in the realm of mathematics and theory.  That is a world where everything is continuous, where precision is infinite, and computational time is unbounded. [...] The world of video games is very different. [...] It is more important for a game engine to provide "perceptually correct" results rather than "scientifically correct" results. [...] You can use real-world physics equations to guide your systems.  Doing much more than that is an exercise in insanity.

There is nothing complicated in his paper. It's even a simplification of the more general case of three-dimensional rigid bodies colliding. At any rate, in both cases, the equations you get from a direct application of Newton's laws allow you to compute the linear and angular momentums at time t+dt given their previous values at time t and the forces applied to the rigid body, just by computing a few matrix products, norms, dot products and cross products. No need for infinite precision, no need for infinitesimal time steps and certainly no need for a supercomputer.

I think you just set the bar too high.

Well, any lower than that would restrict the generality of the algorithms derived from this study. It IS possible to compute good-looking, accurate physics that is not CPU-intensive without resorting to whatever doesn't look too bad, like adding a velocity proportional to penetration depth and whatnot.



You may want to have a look at rigid body dynamics in general as some of the formalism used in your paper could be simplified or given broader applicability. For instance, you use the determinant of two vectors for what is actually better conceived as the norm of their cross product (it's the same thing, but conceptually, I think it's better to look at it that way). Also, you regard inertia as a real number I which is good for 2D but laerning about the inertia tensor may be a good investment for the future if you ever intend to make a physics engine for 3D objects. I'd advise that you define A and B as functions of (r, n) and (r, n, p) respectively, just for the sake of clarity. We don't want people to believe they are intrinsic to the object at hand, now do we?


That being said, thanks a lot for your contribution. The formulae are sure to prove useful to anyone trying to tackle 2D rigid body dynamics.

#5057576 Question from a noob!

Posted by on 28 April 2013 - 05:07 PM

Coding...ugh, it's my worst nightmare. I'm trying to learn it via youtube, and, it's a killer.

You should start with a simple language to begin programming. I suggest trying Python or Java at first to get a grasp of imperative programming and then object-oriented programming. Then, make very simple applications, text-based. From there you may want to move on to making small games with a simple graphics API, for example by remaking Tetris or the snake game. With that experience, you can try tackling bigger 2d games, with more powerful libraries.


And, regarding your question, to add to what Simon Forsman said, in AAA games there are often many more artists than programmers, therefore the amount of man-hours dedicated to content is greater than the amount dedicated to code (engine or game code). If you're only starting, you are going to spend most of your time programming at first.

#5010075 A few design ideas

Posted by on 12 December 2012 - 11:27 PM

Well, you said it yourself, you found your inspiration in several existing games so not one of these is extremely original and attractive, but that doesn't mean they couldn't lead to good games. About Steal-It!,

This idea still requires a lot of work

well yes it does :

you must outsmart the other team and can use distractions and even attempt to get the other team caught by security forces.

Just how do you do that? The game mechanics would have to allow for moves more or less smart. Are these security forces supposed to be intelligent? If they are, then AI might be a challenge during development, unless you're ok with simple behaviors as in the Metal Gear series.

Regarding the worst game in the world,

Compete with friends on leaderboard style game play

What is "leaderboard style game play"? If you simply mean having players ranked according to some score, then this ranking has to be meaningful: there have to be varying degrees of ability leading to higher or lower scores. The game must be able to differentiate players based on talent.
A lot of adventure games rarely involve gameplay mechanics that require players to push themselves to win, like finding almost random objects and combining them together or with an entity in the level to move on to the next room or whatever. Either you find them and use them, or you don't. Sometimes there are several possible outcomes, but always in a rather small, finite number.
The complete opposite of that is found in classic competitive games like Starcraft 2, Counter-Strike, etc. There's a broad spectrum of possibles levels of play which allow for meaningful rankings of players.
Games like Wario Ware are highly repetitive and, after some time, you know them inside and out and hardly fail at the minigames anymore. I feel that's incompatible with players being ranked in any meaningful way. While i don't believe it impossible to make a competitive game with the Wario Ware basic mechanic of minigames, you'd need to describe very specifically in what way the game is competitive. As a programming exercise, and for the lulz, you could very well make such a game, because some game mechanics are truly abused of. Don't forget to add achievements for launching the game, pressing a button and earning your first point.

Regarding Space Port Manager, at the heart of the game would lie an economic system. Without it, no game. The idea is not bad, but not good either a priori, but with this kind of game, only after the economic system has been specified, developed and tested can you tell whether the game is any good.

All in all, none of these ideas is bad but I think you need to flesh them out before we can give you constructive advice. Cheers!