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
377 views

Physics engine deltaTime and force acceleration

I am working on a physics engine that uses basic Euler integration to compute forces. So, here is the thing: function applyForce (rigidbody, force) { rigidbody.forces.add(force); } function ...
1
vote
2answers
111 views

How can I compute the movement of an object along a parabola?

I am working on a simple 2D game. In the game, I have a 'robot' that throws a ball towards another robot, in the shape of a parabola. Both 'robots' have the same Y coordinate. The program knows the ...
0
votes
1answer
760 views

OBB Collision Resolution: Jittering with Long Rectangles

I have been working on a physics simulation module. Almost everything works properly, but I am having an issue, which I have demonstrated in the following video. http://youtu.be/2L17y9Lme0Q As you ...
4
votes
1answer
235 views

How can I test if an object will “fit” during pathfinding?

I'm tinkering around with a 2d game where obstacles are polygons of arbitrary shapes, sizes and locations, and movable entities (players/enemies) can also be of arbitrary sizes. What's a good general ...
0
votes
1answer
150 views

Box2D + Citrus Engine - Proper Pong Paddles

I am creating a pong clone for my first Citrus Engine project using Box2D. I've tried two types of paddles, both do not fully work. 1) Paddle is a dynamic body with a restitution of 1.0 and friction ...
0
votes
3answers
257 views

How do I prevent other dynamic bodies from affecting the player's velocity with Box2D?

I'm working on my player object for my game. PhysicsBodyDef def; def.fixedRotation = true; def.density = 1.0f; def.position = Vec2(200.0f, 200.0f); def.isDynamic = true; def.size = ...
4
votes
2answers
419 views

Why are we not using integers in game physics?

We can use integer for game physics (or without physics, simply object representation): mass, position and rotation, where the integers represent, for example, the number of milligrams, millimeters or ...
-1
votes
1answer
2k views

No collision detected with 2D rigidbody

No collision detected with 2D rigidbody 0 I have a ZombieBoy with a circle collider2D and a box collider2D and a RigidBody2D . The player shots energy balls which has a Circle Collider2D and a ...
0
votes
2answers
5k views

Why would Rigidbody.AddForce not resulting in movement of my objects?

I'm trying to get my card objects to spread out randomly but nothing happens. I know the method is called cause I get the prints in the console for each card. But they don't move. No errors reported. ...
2
votes
1answer
230 views

Using Box2D / Physics with Tiles?

Here is my issue. I currently have Box2D setup and working. But, it works with my Entity system. So I can create static objects and dynamic moving ones, and they simulate fine. However, my world is ...
1
vote
2answers
239 views

How can I get the force of a collision in Love2D?

Is it possible to get the force of a collision between two objects in Love2D/Box2D? If so, how?
3
votes
1answer
401 views

Car physics - velocity and latheral force

Im developing simple car racing game. To turn a car, I need to calculate slip angles for each tire and then use those angles to find lateral force (using Hans B. Pacejka magic formula). One thing I ...
1
vote
2answers
67 views

Controls: Rolling on a ceiling

Currently I'm writing an iOS game where the basic movement is rolling. Technically you make the player turn clockwise or counterclockwise. When you tilt the device to the right, you will rotate ...
3
votes
2answers
93 views

Radiometric quantities and time in rendering

Often in papers people use various radiometric quantities, mostly radiant flux, radiant intensity, radiance and irradiance. It seems to me that all of these quantities are dependent on time. For ...
2
votes
3answers
283 views

How can I determine trajectory from distance and time, without initial velocity?

I'm attempting to develop a Mortar that needs to lead it's shot to the target enemy. The shot will have a pre-determined constant flight time of (2.5 seconds) and it will have where the enemy should ...
4
votes
1answer
287 views

Why do my velocity estimates have such a large margin of error

I am writing a script in unity that applies a force to the object to advance it a set distance in an environment without friction or drag, producing a cosine force curve. However, as the target ...
1
vote
2answers
162 views

Collision Scenario, Detection and Response

I have AABB, BSphere, a Polygon Soup, a Triangle, a Plane, a Point and a Ray objects with a collision test that returns 'bool' if two objects collide or not. How can I use the above objects to ...
2
votes
1answer
526 views

bullet character controller sliding down any slope gradient

I've been experimenting with the btKinematicCharacterController. I've seen very old complaints that it has issues but I can't find anything recent stating that these issues remain (and nobody ever ...
1
vote
1answer
124 views

Lunar lander: why is my descent module crashing

I've been reading this awesome simulation of the actual Apollo 17 descent: http://www.braeunig.us/apollo/LM-descent.htm I've been trying to make my own simulation using Euler integration, with a time ...
-1
votes
2answers
187 views

Using Geometric Slerp to move Camera

I'm writing a program in C++ using OpenGL and GLM; I'm trying to get my camera to follow my car. So far it successfully follows it around the screen, but I'm having trouble adjusting the Camera's ...
1
vote
1answer
227 views

How can I implement jumping in a 2D game using bounding box collision?

Problem: I'm trying to implement basic jumping to my 2D game engine, but have failed several times. Basically what I've done so far is disabling gravity and using a separate function moving the player ...
-1
votes
1answer
103 views

Can not seem to adjust the speed of my Car

I'm programming in C++, rendering in OpenGL and using GLM for matrix/vector manipulation and I have implemented very (very) basic car controls; ignoring many forces that are present in reality. Since ...
1
vote
1answer
106 views

Farseer - Difference between Position, GetLocalVector, and GetWorldVector

I have used Box2D extensively, and am used to just calling body.GetPosition(). But Farseer does not have this. Instead it has a property Position, as well as methods GetLocalVector and GetWorldVector. ...
0
votes
1answer
130 views

Lunar lander: How to calc acceleration in each step

I'm trying to make a lunar lander simulator. I'm going to use a simple Euler integration. AFAIK all I've to calculate is the acceleration in each step, and then I should be able to update velocity and ...
8
votes
3answers
413 views

Make fast thing look slow (Box2D)

I'm working on a game that you control a trebuchet to throw balls to the opponent. It's like a game called 'Medieval Siege'. When the trebuchet is swinging its arm, player need to seize the best ...
1
vote
1answer
1k views

Basic Car Movement, Converting 2D Vectors to 3D problems

I'm trying to follow this guys method for steering a basic car. Link. It's the first example I can sort of get my head around and I'm trying to convert it to a working 3D version. To get some scope, ...
0
votes
1answer
300 views

Circle vs. Rect Collision accuracy problem

The blue ball is dynamic and is supposed to bounce off the walls, as well as the rectangle. Currently, the green rectangle is adding an invisible line to the scene, which doesn't let my ball go where ...
0
votes
2answers
245 views

Best collision shape for rooms

I'm wondering what is the most efficient collision shape to use with APIs like Bullet or Havok for rooms/interiors. Rooms tend to be boxes but are concave since the normals point inward which means no ...
1
vote
1answer
102 views

How to show the bow string stretching animation (?)

I was wondering how the animation in the angry birds of pulling the slingshot is done. One similar animation is available in this game but with a bow and arrow. I think both of them use the almost ...
1
vote
1answer
389 views

Making player movement direction follow players facing direction

if (controller.isGrounded) { moveDirection = new Vector3 (Input.GetAxis ("Horizontal"), 0, Input.GetAxis ("Vertical")); moveDirection = ...
1
vote
1answer
211 views

Block player movement

What do i need to keep my player model from going through environment objects like walls, trees etc? Im trying to figure out if should use rigid bodies and the built in physics but i feel that its ...
2
votes
4answers
306 views

Using forces to reach a specific velocity

In my game, I currently move the player by directly setting its velocity on key press events. This makes the game feel very responsive and allows the user to quickly change direction. However, I ...
23
votes
4answers
2k views

What is the point of “delta” in this code? Does it reflect a standard thing in game dev?

I know very little about game programming but would like to learn more. I am trying to understand the code for this game. I am trying to understand why the code is passing a "delta" to ...
1
vote
0answers
108 views

How to aim with a spaceship in 3D considering its angular momentum?

So I have a spaceship and I have 6 degrees of freedom. At a given moment the following vectors are known of the spaceship: Local forward. Local up. Local sideways (may be implied from the previous ...
-1
votes
1answer
143 views

How to make “they need to be fed” movement style [closed]

This is the game for people who don't already know it: youtube video I am looking for theory about making an object move around another object and stay stuck to it. How would I implement something ...
0
votes
0answers
59 views

how to stop enemies from moving to one point when lots of them are chasing one object [duplicate]

i am making a top down game which lots of enemies are chasing one guy. then,enemies would move to one point without any collision,they just overlay each other. so ,is there any simple way to make ...
0
votes
1answer
351 views

Rope Colliding with a Rectangle

I have my rope, and I have my rectangles. The rope is similar to the implementation found here: http://nehe.gamedev.net/tutorial/rope_physics/17006/ Now, I want to make the rope properly collide ...
5
votes
6answers
430 views

Increasing efficiency of N-Body gravity simulation

I'm making a space exploration type game, it will have many planets and other objects that will all have realistic gravity. I currently have a system in place that works, but if the number of planets ...
22
votes
7answers
2k views

Multithreading 2D gravity calculations

I'm building a space exploration game and I've currently started working on gravity ( In C# with XNA). The gravity still needs tweaking, but before I can do that, I need to address some performance ...
1
vote
1answer
95 views

Box2D relations

As far as I know, the unit in Box2D is meters. When I use Box2D in Processing with JBox2D, I set the "world size" as the window size specified in the setup(). Now I'm wondering if there is any ...
4
votes
1answer
144 views

Correct order of tasks in each frame for a Physics simulation

I'm playing a bit around with 2D physics. I created now some physic blocks which should collide with each other. This works fine "mostly" but sometimes one of the blocks does not react to a collision ...
4
votes
1answer
180 views

How to manage sleep/awake state of physics body

I have a loop, which updates all the physics, inside the loop I'm updating the position of the objects, first thing is the gravity, which pulls all the objects to the bottom. Now my question is, how ...
5
votes
1answer
504 views

Do I need path finding to make AI avoid obstacles?

How do you know when a path-finding algorithm is really needed? There are contexts, where you just want to improve AI navigation to avoid an object, like a space -ship that won't crash on a planet ...
1
vote
3answers
427 views

Bouncing ball isssue

I am currently working on the 2D Bouncing ball physics that bounces the ball up and down. The physics behaviour works fine but at the end the velocity keep +3 then 0 non-stop even the ball has stopped ...
1
vote
1answer
3k views

Jumping with Mecanim synchronization

I am using Unity3D 4.1 for one of my projects. I have a robot character which is always running. I am using mecanim animation system. What I really want:When I press Space bar, the character should ...
1
vote
1answer
111 views

Adding Leniency to Jumping Mechanic

I have written some jumping code for my player in a platformer game. At the moment it has some basic logic which says that the player can jump if he is on the ground. The pseudocode looks something ...
4
votes
4answers
648 views

The physics equation for a perpetual seesaw

I am trying to create a game that involves two or more people jumping on a seesaw and propelling each other in the air. I need help with the physics equations Assume no friction and no air ...
0
votes
2answers
122 views

How can I simulate a rigid body bounced from a wall in 3D world?

How can I simulate a rigid sword bounced from a wall and hit the ground (like in physical world)? I want to use this for a simple animation. I can detect the figure and the size of the sword (maybe ...
0
votes
1answer
262 views

Performing intersection testing in world's or object's space?

Am adding basic ray casting and collision detection for my game, also adding bounding volumes/collision mesh. Given that the ray is cast in world space and each mesh's node can track world ...
0
votes
1answer
650 views

Box2d making a body follow the mouse accurately

I am trying to make a box2d b2Body follow my mouse position. This is the code I am using at the moment but it is not performing very well: deltaPos = mousePos - body->GetPosition(); deltaPos *= k; ...