Tagged Questions

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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0
votes
1answer
294 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
237 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 ...
0
votes
0answers
38 views

Rotate to face a direction in ODE

I'm trying to code some AI for a space flight simulation game. I have a function called seek that returns the desired velocity to head towards a target. My problem is now applying this to an ODE ...
1
vote
1answer
98 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
349 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
195 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
292 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
101 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
142 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
327 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
382 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
93 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
154 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
449 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
405 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
2k 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
108 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
566 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
114 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
246 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
541 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; ...
6
votes
1answer
336 views

2D Polygon Triangulation

I am creating a game engine using the JBox2D physics engine. It only allows you to create polygon fixtures up to 8 vertices, To create a body with more than 8 vertices, you need to create multiple ...
3
votes
1answer
121 views

What is a collision shape?

I am a business developer who is new to game programming. In learning Stencyl, I see that there are things called collision shapes associated with tiles. This seems to be a standard term in game ...
0
votes
1answer
339 views

Trouble with a modified parallax scrolling concept

I have a set of layers (each of them being a list of items) moving with different speeds as I mentioned here: http://stackoverflow.com/a/18962019/270197. Layers back in the scene move with slower ...
1
vote
1answer
100 views

How to reduce the time it takes to speed up an object?

I have a body that I am applying a force to every step. However, I it takes a significant amount of time for it to speed up, which I do not want. Is there some value I can adjust to help with this?
-1
votes
1answer
373 views

Air Resistance of a Falling Object

I am applying air resistance to a falling sphere using the Euler method. If someone could have a look and tell me if my implementation is correct or offer any tips, it would be highly appreciated. ...
4
votes
1answer
1k views

GGX specular BRDF is way over 1!

Now, the classic Torrance derivation for roughened surfaces which Cook took into vectorized form yields the familiar parametrization of a specular BRDF where we have the NDF which decides how much ...
1
vote
1answer
786 views

Need to translate a Rotation Matrix to Rotation y, x, z OpenGL & Jitter for 3D Game

I am using the Jitter Physics engine which gives a rotation matrix: M11 M12 M13 M21 M22 M23 M21 M32 M33 And I need it so OpenGL can use it for rotation GL.Rotate(xr, 1, 0, 0) GL.Rotate(yr, 0, 1, ...
0
votes
0answers
1k views

Platform game: applying gravity and jumping [duplicate]

I am making a 2D platform game in Java but I don't know how to apply gravity and jumping on my player and other living creatures in game that it looks natural and that it is physical correct. I have ...
2
votes
2answers
385 views

Canting of track in a racing game

I am trying to create a small racing game in which the track would be modeled using a BSpline curve for the path's center line and directional vectors to define the canting of the track at each point. ...
0
votes
1answer
355 views

Showing trajectory indicator

From the image you can see that the ball fired on the left that fire behind it, does not match the calculated trajectory. Im drawing the ball trajectory using an equation from a SO question, this is ...
7
votes
2answers
350 views

How to implement a tractor beam?

I'm working on a game where the player can pick up objects using something like a tractor beam, and carry them around. Attracting the object towards the center of the beam is not difficult. But once ...
2
votes
0answers
184 views

Collision detection with an irregular curve

I'm building a custom physics engine to accompany a level-editor. This image shows how the level-editor outputs levels: Now, some explanation is in order. The curve is defined by the red points. ...
0
votes
1answer
201 views

Issues calculating frame independent movement

I'm developing a Breakout style game in C++ using SDL. The problem so far is that the ball slows down and speeds up for no particular reason. The slowdowns usually last a few seconds. EDIT : When ...
1
vote
1answer
503 views

How can I implement a simple “jump” action with three.js and/or Physijs?

Assume I have a simple Physijs object like this car. How can I adapt something like this to "jump" (hydraulics ftw!) when pressing spacebar for instance? I'm currently thinking applyCentralImpulse ...
-1
votes
2answers
438 views

Move a player in the opposite direction they are looking

I'm looking to move the player in the opposite direction they are facing with a specified force. Rather than try to explain that better I created an image showing what I mean, I've tried reversing ...
9
votes
1answer
365 views

Multiplayer platformer - Are server corrections normally required with a single client on the server?

I am currently working on a rather simple multiplayer platformer. I read quite a bit of articles on the techniques used to hide latency, but I still fail to get my head around certain of the concepts. ...
3
votes
1answer
324 views

Simple 3D collision detection for general polyhedra

I have correctly set up a SAT system. I now need to determine a simple, fast, and general purpose collision detection mechanism to identify the collision points. These points will then be used to ...
3
votes
2answers
915 views

Unity 4 - Some Rigidbodies Won't Fall Asleep

I'm having this problem in the free edition of Unity 4.1 where rigidbodies aren't falling asleep (and yes, I've tried playing with the sleepVelocity and sleepAngularVelocity values!). I've read the ...
7
votes
1answer
2k views

A simple flight simulator

In a 3D flight simulator with a Crimson Skies level of realism (as in, arcade level rather than realistic), how do you determine the movement of an aircraft each game clock tick? (Crimson Skies is an ...
3
votes
1answer
273 views

GPGPU physics & game logic

I'm wondering about gpu accelarated physics after reading about Erwin Coumans presentation on GPU accelerated physics: http://www.gdcvault.com/play/1018185/GPU-Rigid-Body-Rigid-Body (demo video here: ...
1
vote
3answers
603 views

How to move around a player in a curved tunnel?

In a scenario where the player moves freely along the walls of a tunnel (like this), what is the best way to move the player along the walls of the tunnel? I'm using Unity3d game engine. I've tried ...
4
votes
3answers
162 views

Particle dynamics simulation and conservation of energy

Suppose you want to simulate the dynamics of a particle subject to Newton's laws of motion. We could just fix a discretization of the time dt and solve approximate differential equations like ...
0
votes
1answer
192 views

Resolving a collision between point and moving line

I am designing a 2d physics engine that uses Verlet integration for moving points (velocities mentioned below can be derived), constraints to represent moving line segments, and continuous collision ...
0
votes
1answer
897 views

gamemaker getting a ball to bounce 90 degrees off of a 45 angle

I am trying to get a circle to bounce off a 45 degree diamond shap using Gamemaker Studio. I would like the ball to bounce in straight lines so my directions would be 0, 90, 180, or 270 degrees, ...
0
votes
1answer
304 views

How to simulate the movement of a ball in 2D due to force, gravity, and friction with surface?

I have a ball which I kick with some force. It has a starting x,y position, sat (2,3) and an intended target x,y say (7,8) position. That means I have to translate by (7-2, 8-3) i.e. 5 x units and ...