# Tagged Questions

3answers
182 views

### How do I resolve a sphere-triangle collision in a given direction?

I am trying my hand at game physics. I understand that the basic way to pull back a sphere when it collided is to negate the penetration distance: // If collided... // distance: distance form ...
0answers
15 views

### Understanding the use of MTV for an elastic collision response

So, I'm trying to simulate polygon physics, both linear and angular. To calculate the MTV is easy in SAT (Minimum Translation Vector), and to use it to adjust position is also easy: PolygonA.center ...
0answers
76 views

### Realistic collisions with a kinematic rigidbody?

I have a car game where player drives a car; this car has a collider and a kinematic rigidbody attached and is completely controller by script (i.e. a script sets its position and rotation). In the ...
0answers
109 views

### Polygon Collision Response

I'm working on a game engine that has a built in custom physics engine (I know it's a waste of time, but I have years to make this, so why not make it good?). Currently, with any number of polygons, ...
3answers
206 views

### Do two balls of different mass bounce different heights?

There are two balls and the only difference between them is the mass. Both are dropped from the same height on to the floor (static object with infinite mass), would both balls bounce up to the same ...
1answer
372 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 ...
1answer
176 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 ...
1answer
688 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, ...
1answer
206 views

### Is it possible to get the colliding sides using the separating axis theorem?

The title says it all, is it even possible to get the colliding sides? I'm checking for collisions between two OABBs, which works fine using SAT. Now I want to set the moving object's velocity to the ...
2answers
268 views

### When to detect and respond to collisions?

I've usually implemented collision detection like this in the past: Move entity Check if it collides with anything Resolve the collision by moving it back That's also the approach employed by most ...
1answer
499 views

### How to calculate collision normal between two AxisAlignedBox's?

I'm writing a physics simulation in Ogre3D and I'm trying to figure out how to calculate the collision normal between two Ogre::AxisAlignedBox's. I am checking for collisions using the "intersects" ...
3answers
1k views

### Resolving a collision with forces

In my 2D physics engine, I can detect AABB vs AABB collisions, and resolve them by finding the shortest penetration vector and adding it to the AABB's position. Doing this "pushes" the first AABB ...
3answers
339 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 ...
0answers
161 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. ...
1answer
473 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 ...
1answer
128 views

### Help with Collision Resolution?

I'm trying to learn about physics by trying to make a simplified GTA 2 clone. My only problem is collision resolution. Everything else works great. I have a rigid body class and from there cars and ...
1answer
1k views

### 2D OBB collision detection, resolving collisions?

I currently use OBBs and I have a vehicle that is a rigid body and some buildings. Here is my update() private void update() { camera.setPosition((vehicle.getPosition().x * camera.getScale()) - ...
1answer
367 views

### Simple (and fast) dices physics

I'm programming a throw of 5 dices in Actionscript 3 + AwayPhysics (BulletPhysics port). I had a lot of fun tweaking frictions, masses etc. and in the end I found best results with more physics ...
2answers
2k views

### How to implement friction in a physics engine based on “Advanced Character Physics”

I have implemented a physics engine based on the concepts in the classic text Advanced Character Physics by Thomas Jakobsen. Friction is only discussed very briefly in the article and Jakobsen himself ...
1answer
1k views

### Resultant Vector Algorithm for 2D Collisions

I am making a Pong based game where a puck hits a paddle and bounces off. Both the puck and the paddles are Circles. I came up with an algorithm to calculate the resultant vector of the puck once it ...
2answers
2k views

### How to resolve penetration of two colliding bodies

I've implemented simple 3D game physics engine. I already have decent collision detection in place, now I'm trying to figure out the collision response part. I'm using impulse based method to ...
4answers
3k 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 ...
4answers
2k 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 ...