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
1answer
670 views

physics of 2D car racing game with heightmap

I want to develop a simple car racing game where the road is defined by a heightmap. It looks basically like this: The player can use throttle and brake to control the car. I'm wondering what the ...
5
votes
2answers
695 views

Ball bouncing infinitely and constantly

Alright, so I've got hold of some simple physics mechanics, and am currently trying to implement bouncing. Based on the first answer of this question, I've developed the following algorithm: ...
1
vote
1answer
622 views

Collision detection against specific sprite shape using XNA with Farseer Physics?

I am making a 2D XNA Game, using Farseer Physics for collisions. I need collisions to be resolved against the actual shape of the sprite image, ignoring transparent pixels, rather than against the ...
-2
votes
1answer
121 views

Help finding a good XNA physics library? [closed]

I'm looking for a good physics library for XNA. Can anyone help me find something good, simple and easy to learn for XNA?
3
votes
1answer
168 views

What to do after detecting OBB-OBB intersection

I'm using this code to detect intersections between two OBBs. The problem is that i don't know what to do after detecting it. I tried using a simple algorithm: if (collision detected) { ...
1
vote
0answers
51 views

how to make virtual environment consistent in networked applications? [closed]

I have a Virtual Environment(grid of cubes) which has the same state on both users when the application starts. Both users have haptic devices, whose position is depicted by a small sphere in the ...
0
votes
1answer
283 views

Simple Motor Vehicle Acceleration Function

So I have a simple 1D "racing" game, with a single button the player can press to max the gas pedal and there is also some other stuff going on. I think acceleration should be highest somewhere at ...
6
votes
3answers
404 views

Calculating impulse propagation through a rigid body after a collision

I'm working on a game. I need to work out what the impulse is at different points on a body as a result of a collision. For example, in the following diagram, if there is a collision that results in ...
1
vote
2answers
826 views

Find the Contact Normal of Rectangle Collision

It seems a lot of people have asked similar questions on this site, and every time it seems like a whole bunch of answers that don't work are given. Basically, I have two rectangles (AABBs) that ...
2
votes
1answer
396 views

Am I implimenting a sweep and prune broadphase correctly? [closed]

The code that I am using is: std::vector <PhysicsBody*> physicsChildren; //containing all objects ... std::sort(physicsChildren.begin(), physicsChildren.end(), sortByLeft); ...
0
votes
2answers
1k views

How to make a smooth movement in XNA?

I'm trying to make a nice controls for my game, but I can't achieve enough SMOOTHNESS. if (kbState.GetPressedKeys().Length != 0 && _direction != Vector2.Zero) { ...
3
votes
2answers
1k views

Non-physics character movement in a Box2d Environment

I am in the process of creating a physics platformer. However, I want the player movement to feel very old-school(as in: non-physics like), which means that the character: Should always move equally ...
1
vote
0answers
189 views

How do I implement a physics gun?

I'm currently trying to implement a physics gun for my game. What I want is for the entity to stay in the same position on the screen no matter how I wiggle the camera about, what is the correct way ...
1
vote
1answer
332 views

When and where should I calculate collision response with multiplayer physics?

I've troubles wrapping my head around multiplayer physics and collisions on the client side, so far I interpolate the state of my network entities ( position and velocity ) of the other clients based ...
1
vote
1answer
1k views

Unity3D: collider performances on mobile iOS devices

I'm experimenting with Unity3D and colliders. Unfortunately I still don't have Unity Pro version and I can't use the profiler. Consider the following situation: mobile devices (ios, iphone 3GS). an ...
2
votes
2answers
477 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
250 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
251 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
142 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 ...
9
votes
2answers
2k views

How can I make a character walk on uneven walls in a 2D platformer?

I want to have a playable character who can "walk" on an organic surface at any angle, including sideways and upside-down. By "organic" levels with slanted and curved features instead of straight ...
0
votes
1answer
166 views

Separating Axis Theorem fails at certain angles

I'm currently attempting to add an overlap tester for an axis aligned and orientated bounding box but the solution only seems to work accurately when the OBB's angle is between -10 and +10. As the ...
0
votes
2answers
146 views

Circle Collision class not positioning itself correctly

Ok I am using unity3D and the Futile framework. I have everything drawing and working correctly with Futile, but I am trying to attach a circle collision class to the FSprite that I have. I must be ...
1
vote
2answers
353 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
180 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
662 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
92 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
328 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
373 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 ...
1
vote
1answer
296 views

What physics engine support force fields and bodies represented as points?

I need a game engine that supports force fields in 2d or 3d, but suitable for 2d calculations, like bullet. Each body I want to simulate is represented as a set of points. Each point has positive ...
2
votes
3answers
830 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
340 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
546 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 ...
-3
votes
1answer
299 views

Implementation of planets in top-down space shooter [closed]

I am working on a top-down space shooter, and I have come to the point where I need some input on a mechanic. I have implemented enough that I can make this choice; either way will not change the code ...
2
votes
1answer
448 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
332 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
263 views

Physics/Logic behind self-bounce

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 (mostly) rubber, and pulled the top of itself inward and then ...
1
vote
1answer
123 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
782 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
489 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
236 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
819 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
878 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
4k 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
289 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 ...
10
votes
3answers
793 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
663 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
247 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 ...
3
votes
1answer
398 views

2D Smooth Turning in a Tile-Based Game

I am working on a 2D top-view grid-based game. A ball that rolls on the grid made up of different tiles. The tiles interact with the ball in a variety of ways. I am having difficulty cleanly ...
0
votes
1answer
230 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
264 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 ...