Questions tagged [physics]

Relating to the motion of objects through space and time. Including concepts such as acceleration (thrust and gravity), mass, collision response, friction and more.

Filter by
Sorted by
Tagged with
265
votes
11answers
102k views

When should I use a fixed or variable time step?

Should a game loop be based on fixed or variable time steps? Is one always superior, or does the right choice vary by game? Variable time step Physics updates are passed a "time elapsed since last ...
46
votes
2answers
75k views

How to make a character jump?

I am currently making a game in C# using Direct X 9.0. The game remake is Donkey Kong NES. I have nearly everything completed, but I am having problems with the physics of Mario's jump. I have ...
0
votes
1answer
3k views

Car driving through walls with transform.Translate()

I need help with a script for a very simple car that uses transform.Translate: ...
32
votes
5answers
13k views

Lag compensation with networked 2D games

I want to make a 2D game that is basically a physics driven sandbox / activity game. There is something I really do not understand though. From research, it seems like updates from the server should ...
1
vote
2answers
403 views

Nestling into contact with a group of physics objects without exerting forces on them

I'm making a pool game, and would like the circle (imaginary) to be in contact with the table and balls, and to fit perfectly as a ball would. Now I thought I would use Rigidbody and lerp the ...
5
votes
1answer
1k views

Spaceship acceleration for following waypoints

I'm creating a turn based space ship strategy game with simultaneous turn resolution similar to Steam Birds. After all the orders are given, the ships run through a real time simulation where they ...
75
votes
5answers
43k views

Good 2D Platformer Physics [closed]

I have a basic character controller set up for a 2D platformer with Box2D, and I'm starting to tweak it to try to make it feel good. Physics engines have a lot of knobs to tweak, and it's not clear to ...
12
votes
4answers
12k views

Finding the contact point with SAT

The Separating Axis Theorem (SAT) makes it simple to determine the Minimum Translation Vector, i.e., the shortest vector that can separate two colliding objects. However, what I need is the vector ...
33
votes
11answers
76k views

In Pong, how do you calculate the ball's direction when it bounces off the paddle?

I'm trying to wrap my head around this very Hello World-y problem in game development. I've created a TicTacToe game in XNA so I guess the next step would be a Breakout clone. Keep in mind that I ...
7
votes
5answers
6k views

How to lead a moving target from a moving shooter

I saw this question: Predicting enemy position in order to have an object lead its target. My situation is a little different though. My target moves, and the shooter moves. Also, the shooter's ...
12
votes
3answers
2k views

Impulsioned jumping

There's one thing that has been puzzling me, and that is how to implement a 'faux-impulsed' jump in a platformer. If you don't know what I'm talking about, then think of the jumps of Mario, Kirby, and ...
4
votes
1answer
1k views

How to implement deceleration and stopping over a certain distance [duplicate]

So I have a a character, say a spaceship. It needs to move distance R, and in direction T (Theta). So say if The object is at (0,0), and it needs to get to (4,3), it has R = 5 and T = about 36 degrees....
51
votes
6answers
75k views

How can I implement gravity?

How can I implement gravity? Not for a particular language, just pseudocode...
10
votes
5answers
15k views

How do I detect the direction of 2D rectangular object collisions?

After this question, I need some more help. How can I find out which side of a rectangle a collision came from and react accordingly? The blue arrows are the paths that some circular objects would ...
51
votes
7answers
10k views

2D Platformer AABB collision problems

I have a problem with AABB collision resolution. I resolve AABB intersection by resolving the X axis first, then the Y axis. This is done to prevent this bug: http://i.stack.imgur.com/NLg4j.png The ...
19
votes
1answer
10k views

How do I detect ledges?

In my game, I'd like my character to be able to grab and hold onto ledges, and to be able to pull themselves up if there's room to do so. How do I detect if there's a ledge, and if the character has ...
15
votes
3answers
21k views

Is there an algorithm for a pool game?

I am looking for algorithm to calculate direction and speed of balls in a pool game. I am sure there has to be some type of open source code for this since pool games are some of the oldest computer ...
15
votes
4answers
4k views

How do I calculate rotation caused by bounce friction?

Following on from my previous question: I have the ball quite realistically bouncing from surfaces it hits. Now I'd like to make it spin from the friction of the hit. Showing this is simple enough: I ...
4
votes
2answers
7k views

How can I accurately simulate orbits in Unity?

I would like to create a space simulation with realistic gravity. This means planets in 3d space which act as central gravity sources and multiple objects which are attracted by those planets gravity ...
1
vote
2answers
1k views

Camera relative movement is pushing into/off the ground instead of parallel

I'm building upon roll a ball tutorial in unity, and I have managed to rotate the camera around the ball just fine with the code below. But there's one problem. In this code, when I add force to the ...
35
votes
2answers
11k views

How do I make a character capable of walking on walls?

I am trying to get a character to move like a spider: Given a rising slope which a ball would normally not be able to roll up, the spider would slowly crawl up. Similarly, given a mid-air rectangular ...
20
votes
6answers
21k views

How do I build a 2D physics engine? [closed]

The most advanced games I've made are a 8-ball pool game made with the physics engine Box2dFlashAS3 and a platform game with levels. When I did platform games, I've always wished to know how to make ...
21
votes
3answers
6k views

How does one avoid the "staircase effect" in pixel art motion?

I am rendering sprites at exact pixel coordinates to avoid the blurring effect caused by antialiasing (the sprites are pixel-art and would look awful if filtered). However, since the movement of the ...
42
votes
1answer
5k views

How to differentiate landing on top of an object from falling down the side?

I am looking for a conceptual solution to my problem. It's a simple platformer-alike game where player can move horizontally during free-fall. Consider those two cases: In the first case, from game ...
15
votes
2answers
13k views

2D Planet Gravity

I'm trying to make a simple game where a spaceship is launched and then its path is effected by the gravity of planets. Similar to this game: http://sciencenetlinks.com/interactives/gravity.html I ...
6
votes
2answers
1k views

Why isn't this physics code scaling velocities separately?

I'm working my way through this book and I'm trying to work this code out: ...
1
vote
2answers
2k views

How can I determine the direction of the balls after collision in billiards game?

I'm making a billiard game and I have two questions: How do I find the velocity of two balls when they collide with each other and how do I apply it to both balls? I already know the angles that ...
19
votes
2answers
6k views

How are physics or graphics components typically built in a component-oriented system?

I have spent the last 48 hours reading up on Object Component systems, and feel I am ready enough to start implementing it. I got the base Object and Component classes created, but now that I need to ...
14
votes
2answers
4k views

Implementing a homing missile [duplicate]

I'm having some trouble implementing a homing missile that satisfies what I'm looking for. I have already tried the Seeking and Arrival behaviours described in this link, but none of them were what I ...
23
votes
7answers
3k views

How can I Intercept object with a circular motion

I am creating a 2d space game and need to make the spaceship intercept a planet. I have working code for straight line intercepts but cannot figure out how to calculate the planets location in a ...
20
votes
3answers
8k views

Why is RK4 better than Euler integration? [closed]

At the end of these great slides, the author compares all the different integrators presented. One way or another, they all fall short except for Improved Euler Integration and Runge Kutta 4 ...
7
votes
1answer
5k views

How do I determine a good path for 2D artillery projectiles?

I'm building a little "tank wars" game (like this one). I understand the math, and I am able to define a parabola from the launcher to the objective I want to reach. The parabola depends on the ...
6
votes
4answers
7k views

Which Side Was Hit?

I am working on an Android game and I have two objects A and B (both rectangles) and when they collide I simply want to know which side of B was hit. I have detected the collision fine, but I am ...
5
votes
3answers
7k views

Why is my velocity decaying?

Programming in Java. Tinkering around with physics. My entities all have position and velocity. In the main loop, all I'm doing is applying gravity and bouncing off the edges, like so: ...
5
votes
2answers
1k views

Tracking Object Position - Firing on a Trajectory

How can I calculate the position of an object after "firing" it from a fixed point? I am to create a small game - most likely with canvas (pure HTML, JS based) or Adobe Flash - in which the player ...
10
votes
5answers
2k views

How can I simulate shattering glass?

I need to make a simulation with stone thrown through a glass window. How can I accomplish that? I mean, I was thinking about making a 3D model of a stone and glass in 3D Studio Max 2012, shatter the ...
2
votes
2answers
2k views

Calculating initial velocities given trajectory parabola

I'm working on a volleyball game but my maths/physics knowledge isn't quite up to par. I need some help with the following problem: The player can hit the ball from anywhere on the left of the court ...
1
vote
1answer
571 views

Unity2D force of an impact

I don't know how to name what I am searching for... Force, Impact? It's easier to explain with an image for me. We have two GameObjects with colliders, A and B. They can move in any direction (top ...
85
votes
3answers
38k views

How do I create 2D water with dynamic waves?

New Super Mario Bros has really cool 2D water that I'd like to learn how to create. Here's a video showing it. An illustrative part: Things hitting the water create waves. There are also constant "...
48
votes
3answers
3k views

How to determine which thrusters to turn on to rotate the ship?

The configuration of the ship changes dynamically, so I have to determine which thruster to turn on when I want to rotate the ship clockwise or counter clockwise. The thrusters are always axis aligned ...
38
votes
2answers
10k views

Why do we use the Pythagorean theorem in game physics?

I've recently learned that we use Pythagorean theorem a lot in our physics calculations and I'm afraid I don't really get the point. Here's an example from a book to make sure an object doesn't ...
35
votes
6answers
9k views

Implementing a wrapping wire (like the Worms Ninja Rope) in a 2D physics engine

I've been trying out some rope-physics recently, and I've found that the "standard" solution - making a rope from a series of objects strung together with springs or joints - is unsatisfying. ...
31
votes
1answer
13k views

What is the difference between an impulse and a force related to a physics engine?

What is the difference between an application of an impulse and an application of a force in relation to a physics engine?
15
votes
3answers
6k views

How do I handle moving platforms in a platform game?

I don't want to use box2d or anything, I just want simple moving platforms (up-down, left-right, diagonal and circular paths). My question is to handle the update order / control hierarchy so that the ...
22
votes
4answers
10k views

How to deal with corner collisions in 2D?

I'm writing a top down 2d XNA game. Since its my first I'm trying to write the physics and collision stuff myself to learn it. Whenever my player sprite character attempts to move into a position ...
14
votes
3answers
34k views

Determine Resulting Angle of Wall Collision

So I have an object moving in a direction towards a fixed horizontal or vertical wall. How do I compute the angle that the object should bounce off at? The object can approach the wall at an arbitrary ...
12
votes
4answers
2k views

Animated examples of different interpolations formulas: any link? [closed]

I remember having spotted a link to a huge page with different equations to non linear interpolation curves, for example if you want to stop a car smoothly, etc. Those can sometime be useful to ...
11
votes
1answer
8k views

Angle of Reflection

I have this "Breakeout style" game. I have a cannon at the center, blocks around the cannon and pads around the blocks. This is how the game looks like: I've managed to get the collision per ...
6
votes
1answer
2k views

Algorithm for randomly generating reachable platforms

I want to randomly generate reachable platforms on the fly for a 2D game. Right now, I am just creating platforms at random x,y positions. Only 4 platforms can exist at once, so once the 5th one is ...
16
votes
3answers
5k views

Where to start for implementing vehicle physics? [closed]

A little background for myself. I am relatively experienced with 3rd part physics engines such as Havok, Box2D, Bullet and have successfully integrated them in custom engine(s). I have also made a ...

1
2 3 4 5 6