Physics-based Walking (from A New Zero) - physics

I saw this video and I was amazed, and naturally, I want to try to do it myself. http://www.youtube.com/watch?v=P_DeZUg9HiY
Does anyone have any idea how he made the character walk? Look at the video at 1:15. What kind of Bullet physics constraints do you think he's using in the legs? Is he making some kind of springs?

This is a huge area of academic research. See this paper for starters:
http://graphics.stanford.edu/projects/bio-locomotion/
A game could definitely use a much simpler control scheme than that used in the paper.

Related

Top-down Physics Introduction in Chipmunk

I'm trying to create what I'd assume is a very straightforward piece of physics code using Chipmunk on iOS, which will effectively have eight UIButtons move around a UIView of their own accord, bouncing off the edges, and off of each other, at a randomized speed, etc.
As a relatively new coder, I am having a very hard time doing this. I have pulled apart example code from the chipmunk website (even some specifically using UIKit elements) but I am afraid I just don't know enough to establish what forces need to act, how I set them up, etc. I realise that this is a wide question, but all of the tutorial content I've found regarding Chipmunk seems to assume that one's already a proficient programmer, or a proficient physicist and mathematician. I'm a hobby coder and can't spring to pay for any of the professional Chipmunk packages, and since the free version is in C, not Objective-C, even getting it integrated seems like days of work for me.
Chipmunk doesn't seem to be well-documented. For instance, searching for "friction" in the documentation finds a single (unhelpful) instance of the word. If there's no scale, how am I to know what value to enter? I realise I am frustrated and it is easier than I am making it, but it seems like doors are being slammed in my face every way I try to pick this stuff up.
Lots of the tutorials I have found use older versions of Chipmunk too, which huge amounts of stuff have changed from, making them really, really tough to follow along with.
I could really use a bare bones introduction that doesn't automatically assume I can already do it. Is one likely to exist anywhere? Any other tips for how to handle this?
Not sure if you are the same guy I just answered on the Chipmunk forums but there is this new example here which contains a (regular, non-pro) Chipmunk/UIKit example. It's pretty thoroughly commented.
https://github.com/slembcke/ChipmunkColorMatch
To be fair about the documentation, you do have to realize that there are entire textbooks on the sort of physics that Chipmunk covers. While I do feel that the docs sufficiently cover the API, you are right that it assumes that you know the terms and theory. I can't fit all of that into the documentation, and I don't have the time to write that level of a physics primer. There are some things you just have to know like what mass is, what friction coefficients are (and why they have no units or scale), and how forces work. The Chipmunk documentation should not be a go to place to learn that sort of thing.
If you have specific questions, you can always ask on the Chipmunk forums.

Information about Evolutionary Art

I have begun to do some research about Evolutionary Art algorithm. I read a lot of documents about it. But it seems not easy to understand.
The website http://picbreeder.com is a great example for this. But I don't need this in the beginning because it is too complex.
Where can I find some simple code about this in Java? I think read code could help me much.
Thanks!!!
"Evolutionary Design by Computers" By David Bentley (amazon) has a couple of chapters on evolutionary art. However i dont think it includes any code / pseudocode. The canonical GA should do all you need, however the termination condition could be tricky as art is a subjective subject. (Not objective and therefore enumerable)
Hope this helps...
It looks like the EJC library might help you out, and it looks like a number of open source projects/tools come up if you Google for "java evolutionary computing."
I don't know how simple it is, and believe me it needs to be cleaned up a bit, but I have something that might get you started at https://github.com/murmux/Evo/tree/master/assignment2c It doesn't deal with art, rather game theory, but you can use it under the terms of the GPLv3 if you'd like. That uses Genetic Programming... I have another example using a more vanilla EA I might put up later.
Instead of evolving programs to play "Iterated Prisoner's Dilemma," you would evolve programs to generate an art work. The fun part is coming up with a way to "score" an image for its fitness. (Although Picbreeder seems to skip scoring by having you pick the mating pool directly...)
Check this app: EvoPic, its An evolutionary picture creator that uses Steady-State Genetic Algorithm, to produce evolutionary pictures by drawing uni-code characters in a picture box.
Example:

Suggestions about 2D in a "risk"-like game for iOS

The idea of programming a risk-like game for iOS has been around my mind for more than a week, so I thought I should do something about it. I'm not an experienced iOS developer (I haven't done a real project, only tutorials), but I got some notions about both the language and Cocoa Touch.
So, the thing I want to do is a board game, similar to dicewars (see http://www.gamedesign.jp/flash/dice/dice.html). The maps will at some point have hexagonal-tiles, but if it is to much pain for starters, I don't have a problem with regular tiles for the beginning. I want the maps to be dynamically generated, not made in advance. There won't be much on the game screen : the map, divided in areas, the dices, and a HUD.
The main thing I'm grasping with right now is what to use to do the graphic stuff. I have no background in game programming, and very limited in 2D. For my purposes, should I go with Core Graphics/Animation, OpenGL, Cocos2D, or something else ? I would like to avoid starting with a technology, and halfway through the project, realizing another would have be more adapted.
I'm also listening to any advice about game dev in general, map generation, IA programming.. etc. If you have links that answers my question, feel free, I haven't found anything conclusive so far
tl;dr:
I'm wondering how should I do 2D for a simple board game similar to dicewars/risk. No need for collision stuff, just something to draw a map, update it, and display a hud.
Thanks for your time!
I'd suggest Cocos2d: Very easy to get started, has more than enough functionality to cover your requirements (including tile-maps built into the engine), has an active community, and has been the framework used by many successful games.

Any code samples open-source-engines, or open source hex tile games, references for writing Hex Tile based Games?

Using other questions on here I found Amit's Page on Games including a section on Hex Tiles which also links to a game coding wiki here.
I am looking for suggestions:
(a) libraries, engines or code samples in any language. I have found one in python, PGU+pygame, but looking for more.
(b) open source hex-tile tactics or strategy games.
Because google can find things for me, what I'm hoping is that you have actually used one. So if you googled and then posted, then this is nothing better than let-me-google-that-for you. Much appreciated if (i) you have used it, (ii) seriously, any language at all is okay, C/C++, python, java, flash/flex, whatever.
Related question and another related question but .net
Battle For Wesnoth is a complete, open-source, turn-based strategy hex-based game. Its written in C++. Quite a good game too.
I'm sure there would be something valuable in there, although I've only have a brief browse of the source myself.
I used PGU a number of years ago to make a hex based game for PyWeek, you can take a look at the code if you want to. :)
http://www.pyweek.org/e/PySwec/
I've got a more updated version at home which is quite a bit better but unless you actually want to play the game you should be fine with that. :)
Based on another question here on stackoverflow, there is XConq, an open source turn based tile game.

Digital Circuits Half/Full Adders

I am taking a Digital Circuits class in which we do not use a book, only lecture notes. In the section that covers adders I only have 2 small examples covering addition and subtraction of binary numbers. I am pretty sure i am going to have worded problems in the exam such as design a circuit to count something etc. Does anyone know any sites that have example questions and solution for me to go over?
I don't know of any particular sites, but I do know that when I took a similar class, the lecturer was awful and I relied entirely on the textbook. It was Digital Design, by M Morris Mano. I highly recommend it - it's got plenty of problems to go over and has all the information you need in case you get stuck on something.
Wikipedia is a useful resource. The best way to learn electronics is to build your own circuits, preferably with real hardware or using a simulator if the former is not practicable.
P.S. You do not need adders to count events. A cascade of bi-stable flip-flops will do this.