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

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2
votes
2answers
288 views

Help interpreting the physics of a rolling ball

I'm using this article for reference. I understand handling the collision aspect, but I can't figure out how to calculate the new velocity once the ball collides with the ramp. Without it the ball ...
2
votes
2answers
218 views

How do I find realistic 3D paths for stable and unstable flying rockets?

I am building a 3D application that simulates launching small rockets. I want to draw their trajectories. I know that rockets have a degree of stability. I want to include this in the simulation, but ...
2
votes
0answers
187 views

Inverse Dynamics How to [closed]

I have some motion capture data (kinect) that records all body joints (32fps) and I want to take particular positions (for example when a person moves both of his hands up in the sky in celebration ...
1
vote
0answers
115 views

Collision shape and Model problem

I used BEPUphysics for my XNA 4.0 game , the problem is that I load my model.fbx from into the game then add it to the space of physics engine , but when I change the scaling matrix of my Model then ...
1
vote
2answers
201 views

Basic plane kinematics

I never did physics in my life and this is really hard for me. I am currently trying to implement movement in the X and Y axis of a plane, in a video game I am making. What I want to do is, given a ...
4
votes
1answer
167 views

What is the appropriate way to implement collision in 2D worlds?

If I want to create a 2D game map which features areas traversable by a player through standard up/down/left/right inputs, and then have areas that are NOT traversable... perhaps just a bush, or a ...
2
votes
1answer
396 views

How to make a character in a Box2D world jump faster?

I have a question about using Box2D to simulate a physics-platformer. I manage to make the character move to the right and left, and jumping as well. However, jumping seems extremely slow when ...
1
vote
1answer
82 views

Looking for a peer reviewed article that details the benefits of a physics simulation within interactive media [closed]

I'm hoping this is the correct place to ask this question as it is video game related and can be seen as a key ingredient in modern game development. Does anyone know of a peer reviewed article that ...
2
votes
0answers
228 views

Friction due to gravity in an impulse based physics engine

In my physics engine, I'm using impulses to solve collisions. I'm basing all calculations on these equations: impulse = desired_velocity_change * mass impulse = force * time friction_force <= ...
1
vote
1answer
311 views

XNA (BEPU) Physics Performance

Im using XNA 4.0 with the BEPU physics engine v1.2 and I have encountered some performance problems on Xbox. Im not sure if the my mesurements are an expected result of the Xbox (with alot of dynamic ...
2
votes
3answers
498 views

Integrating Scene Graphs and Physics Engines

For some specific reasons, i will have to use a graphic engine based on Scene Graphics with a Physic Engine without this concept. I was thinking about a clear way to integrate both representation but ...
5
votes
3answers
328 views

How is 'mass' handled in video games?

Mass is one of the basic scalar quantities, which is required in most rigid body physics calculations. Does every, EVERY, object which moves in a game get mass defined in the code, or is it allotted ...
4
votes
1answer
370 views

Splitting logic into threads in Java tower defence game

I'm making a tower defence game in Java! It's my first game development. I want to know how many threads Do I need to create in a game, to split logic.. I've made this one: Main App thread (adds ...
2
votes
1answer
328 views

RK4 integration and Continuous Collision Detection

I'm using this method to detect collision between two AABBs. The algorithm is simple, fast and works great. It uses the relative velocity between the two objects to calculate TOI. This works fine with ...
8
votes
1answer
275 views

Calculate bike heading from front wheel heading and velocity

I have a simple top down bike game that I'm trying to add steering to. I would like to know how I use the heading of the front wheel to determine the heading and velocity of the bike. void Update () ...
5
votes
1answer
183 views

Physics/Logic behind self-bounce

I have a game that I am currently working on and I have a problem. What would a ball look like when it makes itself bounce. Say, for example that the ball had its own "inner power", was made out of ...
1
vote
1answer
107 views

Progressively loading the racing arena in a 3D driving sim

I need advice and resources on a 3D car simulator. I want to progressively load the track for the player as I'm thinking of porting the game to mobile devices. This seems too difficult to me as I'm ...
1
vote
0answers
563 views

Unity3d Gravity script issues

I'm try this script out http://wiki.unity3d.com/index.php/Gravity and I'm having some issues with it (it seemed to work when I tried it with an old version of unity) the first issue is of ...
7
votes
2answers
320 views

How does braking assist of car racing games work?

There are a lot of PC car racing games around which have this unique driving assist which helps brake your car so that you can safely turn it. While in some games it just an 'assist', it will just ...
7
votes
1answer
208 views

Determining whether two fast moving objects should be submitted for a collision check

I have a basic 2D physics engine running. It's pretty much a particle engine, just uses basic shapes like AABBs and circles, so no rotation is possible. I have CCD implemented that can give accurate ...
2
votes
1answer
293 views

Apply force to a specific point on a rigid body

In unity I have a rigid body object and would like to apply force to a specific point. For example say I had a cube, I want to hit just the top right corner so it spins as a result. One idea I had ...
6
votes
2answers
498 views

“Super meatboy”-ish replay

I'm making a platformer built from mini-levels - and I want to create a sort of a replay of all the player tries that the player did for the level. My question is - what is the best way to record the ...
6
votes
2answers
2k views

Get collision details from Rectangle.Intersects()

I have a Breakout game in which, at some point, I detect the collision between the ball and the paddle with something like this: // Ball class rectangle.Intersects(paddle.Rectangle); Is there any ...
7
votes
1answer
261 views

How do engines avoid “Phase Lock” (multiple objects in same location) in a Physics Engine?

Let me explain Phase Lock first: When two objects of non zero mass occupy the same space but have zero energy (no velocity). Do they bump forever with zero velocity resolution vectors or do they ...
9
votes
3answers
497 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 ...
5
votes
1answer
432 views

Calculate gears rotation for a realtime simulation

Hi I'm trying to do a game with real time simulations of gears. There is a big Gear with inside a smaller gear. I managed to draw gears with different diameters but equal size teeth, but if i try to ...
-1
votes
1answer
199 views

forward motion car physics - gradual slow

Im having trouble creating realistic car movements in xna 4. Right now i have a car going forward and hitting a terminal velocity which is fine but when i release the up key i need to the car to slow ...
0
votes
1answer
154 views

SFX Played Once per Collision or Hit

I have a question about using Box2D (engine for LibGDX used to make realistic physics). I observed on the code that I've made for the physics here below: @Override public boolean touchUp(int screenX, ...
6
votes
1answer
239 views

How can I derive force vectors from velocity vectors?

I'm making a 2d shooter ala Geometry Wars. I've got my own simple physics at work driving the background grid and all my entities. To move anything in the world I apply a Vector2d force to it. The ...
1
vote
1answer
206 views

Numerical stability in continuous physics simulation [closed]

Pretty much all of the game development I have been involved with runs afoul of simulating a physical world in discrete time steps. This is of course very simple, but hardly elegant (not to mention ...
4
votes
1answer
214 views

How display path ball will bounce?

I'm trying to figure out a way to show the path a ball will travel, so that the player can line up a shot before they fire the ball. I can't think of a way to calculate this path in advance and ...
3
votes
2answers
335 views

How to account for speed of the vehicle when shooting shells from it?

I'm developing a simple 3D ship game using libgdx and bullet. When a user taps the mouse I create a new shell object and send it in the direction of the mouse click. However, if the user has tapped ...
35
votes
3answers
7k views

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. When something hits the water, it creates a wave. There are also constant "background" ...
-2
votes
1answer
193 views

Move projectile in direction the gun is facing [duplicate]

Possible Duplicate: Move sprite in the direction it is facing? I am attempting to have a projectile follow the direction a gun is facing. When using the following code I am unable to make ...
2
votes
5answers
1k views

How to Make Objects Fall Faster in a Physics Simulation

I used the collision physics (i.e. Box2d, Physics Body Editor) and implemented onto the java code. I'm trying to make the fall speed higher according to the examples: It falls slower if light object ...
3
votes
4answers
2k views

How to move a sprite automatically using a physicsHandler in Andengine?

I use a DigitalOnScreenControl (knob with a four-directional arrow control) to move the entity and the entity which is bound to a physicsHandler. physicsHandler.setEntity(sprite); ...
0
votes
0answers
155 views

Simulating smooth movement along a line after calculating a collision containing a restitution of zero in 2D

[for tl;dr see after listing] //...Code to determine shapes types involved in collision here... //...Rectangle-Line collision detected. ...
3
votes
3answers
196 views

Scaling Sound Effects and Physics with Framerate

(I'm using XNA and C#) Currently, my game (a shooter) runs flawlessly with 60 FPS (which I developed around). However, if the framerate is changed, there are two major problems: Gunshot sound ...
2
votes
2answers
244 views

Procedural generation of physics-enabled structures (in a 2D world)

Is it possible to procedurally generate stable structures out of rigidbody objects at a reasonable runtime speed? Imagine Angry Birds's levels kind of structures but generated procedurally.
6
votes
4answers
495 views

Sharing data between graphics and physics engine in the game?

I'm writing the game engine that consists of few modules. Two of them are the graphics engine and the physics engine. I wonder if it's a good solution to share data between them? Two ways (sharing ...
1
vote
1answer
293 views

Point inside Oriented Bounding Box?

I have an OBB2D class based on SAT. This is my point in OBB method: public boolean pointInside(float x, float y) { float newy = (float) (Math.sin(angle) * (y - center.y) + Math.cos(angle) * ...
1
vote
2answers
171 views

Perpendicularity of a normal and a velocity?

I'm trying to fake angular velocity on my vehicle when it hits a wall by getting the dot product of the normal of the edge the car is hitting and the vehicle's velocity: Vector2D normVel ...
1
vote
1answer
438 views

How do 2D physics engines solve the problem of resolving collisions along tiled walls/floors in non-grid-based worlds?

I've been working on implementing my SAT algorithm which has been coming along well, but I've found that I'm at a wall when it comes to its actual use. There are plenty of questions regarding this ...
1
vote
3answers
250 views

What different ways are there to model restitution in a physics engine?

In my physics engine I give a body a value for restitution between 0 and 1. When two bodies collide there seems to be different views on how the restitution of the collision should be calculated. To ...
1
vote
1answer
179 views

Who should respond to collision: Unit or projectile?

In an RTS if a projectile hits a unit. Who should handle the collision? If projectile handles the collision, it must be aware of all possible types of units, to know what damage to inflict. For ...
1
vote
1answer
187 views

What is going on in this SAT/vector projection code?

I'm looking at the example XNA SAT collision code presented here: http://www.xnadevelopment.com/tutorials/rotatedrectanglecollisions/rotatedrectanglecollisions.shtml See the following code: private ...
1
vote
3answers
324 views

Implementing distance joint

I would like to implement something that behaves much like a distance joint / revolute joint in Box2D, however I do not want to throw a whole physics engine at this problem. I'm curious where I might ...
4
votes
4answers
600 views

Point of contact of 2 OBBs?

I'm working on the physics for my GTA2-like game so I can learn more about game physics. The collision detection and resolution are working great. I'm now just unsure how to compute the point of ...
3
votes
1answer
830 views

Engine for 2D Top-Down Physics-Based Skeletal Animation

I just watched at the Sui Generis video, and was completely amazed. Specifically, the part where the big troll thing is beating up the player with his flail. This got me really excited, and I would ...
2
votes
2answers
601 views

What is the best way to check if there is overlap between player and static, non-collidable items in bullet physic engine

I'd like to add non collidable objects (eg: power ups, items, ...) in a game world using Bullet Physics Engine and to know if there is collision between player and them. Some info : there is a lot ...