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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1answer
245 views

Unity - Joint tearing under larger force

I have a chain that is made of connected configurable joints. I used ultimate rope builder for the rope chain creating. The problem is that when i apply a larger force to the chain, it starts to tear ...
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1answer
951 views

Unity Rigidbody gets pushed through collider by another rigidbody?

I'm setting up the interior of a house in a 2D platformer. Inside the house is an NPC with a box collider and rigidbody attached, and the house is boxed in by four edge colliders. My character also ...
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0answers
60 views

How to calculate multiple collision of sphere and triangles?

I have a sphere and a mesh(triangles). When the sphere intersects the triangle, I reflects the vector of speed and everything works fine. But I can't write a good implementation for multiple ...
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1answer
327 views

Sprite Kit - keeping character level with the terrain 2d endless runner

I've been trying to figure this out exhaustively for the past few days and still haven't found an answer. I have an endless runner built using swift where the character is fixed and the terrain moves ...
3
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1answer
168 views

Determine if an object is inside a ship's turn radius, rotation via torque

I have a 3d space game where all ships move around using physics. I am trying to determine if a given object is reachable by a ship at a given velocity and turn radius. I believe the formula for turn ...
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2answers
75 views

unity3d - Object keeps falling down

I have an object that moves towards another object using this line : transform.position = Vector3.MoveTowards(transform.position, target.transform.position, speed * Time.deltaTime); this is it's ...
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0answers
17 views

how to trigger a ball from rotating cube in z axis

how to release ball from the cube which is rotating in z axis, ball should move in Y axis and ball should be reloaded after releasing the ball ?? Thanks in advance cheers Gokul
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1answer
203 views

Physics: calculating angular acceleration in world vs local space

I have a pretty simple rigid body simulation written in Python. In my code I calculate the angular acceleration using formula: angAcc = torque * inertiaTensor^-1 (note row-major matrix order) Now, ...
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1answer
179 views

Collision between a sphere and a mesh(height-map)

I am trying to implement a method that detects the collision between a sphere and a mesh and reflects the vector of speed. I have a method, that detects a collision between a sphere and a triangle and ...
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0answers
186 views

Implementing wall-sliding physics in THREE.js

Yo, Basically I want to make a 3D environment where the player can walk around a 3D world, and collides with objects / terrain like any other 3rd person / 1st person game. The world can contain any ...
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0answers
178 views

Calculate Orbit Path/Ellipse given mass, velocity, and distance (2body)

Calculate and draw the path of an orbit in a 2 body problem given the mass, current velocity, and distance of both bodies? We're working in Unity and will be using the default rigidbody.mass to start ...
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4answers
739 views

How is RTS Local Avoidance Done?

Currently, I'm simulating physics impact forces for local avoidance of units but this method sometimes pushes units out of formation and has very undesirable effects when units clump up. For RTS ...
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1answer
60 views

b2DistanceJoint with frequency equal to 0 vs b2WeldJoint

What is the difference of b2WeldJoint and b2DistanceJoint? They both have frequency and also when you put frequency of Distance Joint to 0 it acts like Weld Joint. It seams that you can create ...
2
votes
1answer
271 views

Why does my character stop a little before landing on the ground?

I made a little game with side-scrolling and a box (the player) jumping across the level. The simple physics are almost done, but I have two problem with the way things behave: On landing, the box ...
2
votes
1answer
152 views

In Box2D, how do I create an infinitely oscillating spring?

How do I create an ideal spring that can oscillate indefinitely using Box2D? A b2DistanceJoint works almost perfectly, but it eventually slows to a stop, even with damping set to 0. I think it is ...
2
votes
1answer
84 views

(Fat) ray cast with MPR OR GJK?

I know that it's possible to see if a line segment or a swept shape (to make a "fat" line segment) intersects objects using MPR and GJK. Is it possible in those situations to find out the distance ...
2
votes
1answer
53 views

Are GPU physics implementations branchless?

I've implemented MPR on the CPU and in pixel shaders (long story!) and there seems to be unavoidable conditional loops both to find the starting portal as well as to find the final solution. I know ...
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vote
3answers
116 views

Ball oblique impact physic in Java?

I know Q3 + Q4 = 90 I searched internet and many physic topics, but not found how to calculate this values in Java? (I found V3 and V4 but not found Q3 and Q4) So how can i calculate V3, V4, ...
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1answer
81 views

Unity 2D Current object force

I'm working on a game with an entity firing a shot. This shot could destroy other entities as well as the entity who generated the shot. My first step was to apply a force to the rigidbody2D of the ...
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1answer
263 views

Simulation of ball movement in a 3d landscape. The easiest way?

I have a landscape(generated via Perlin noise) and a ball. I want the ball to move along the geodesic(implementation of basic physics: gravitation, friction). I thought to do raycast around the ball ...
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2answers
165 views

Circle-Circle collision resolution

This seems easy but I can't figure it out, when I have one circle(c1) collide with another(c2) I give the c2 circle the heading of c1 and send the c1 circle on the normal vector to the heading (the ...
2
votes
1answer
401 views

What is wrong with my 2D orbit calculation?

I am working on a 2D game, and I am working on adding some space physics, so I need to find a way to create a circular orbit. I want to make my game object move on a circular way around a planet. I'm ...
2
votes
1answer
136 views

Speed needed to make a car jump from a ramp

I need to make a car jump from a ramp to another, and I need this to be done using AI so I thought it would be enough to set a fixed speed for my car when near the ramp, in order to let it jump ...
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2answers
342 views

(Unity) Physics based movement vs Straight position change

Unity provides a cool physics engine for game development and I want to utilize it in my game. Shorter version I want to use physics engine for everything else other than character movement because ...
2
votes
1answer
106 views

Twin-stick controls for a cohesive group of agents

I'm trying to implement a classic twin-stick controller for a group of physics-based game objects. Here are the rules I'm trying to follow: Agents always stay close to each other within a certain ...
1
vote
1answer
121 views

Correct way to integrate scaled axis angular velocity into a quaternion

Across my travels on the internet I have came across to ways of integrating a scaled axis angular velocity into a quaternion. The first way converts the angular velocity into an axis angle quaternion ...
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0answers
240 views

How to slow down a Sphere smoothly in a world controlled by force and stop it (Unity 5)?

I am a beginner and I started to use Unity 5. I play with tutorials on the site and documentation. I was basically testing springs, physics materials etc. I have a problem understanding probably a ...
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0answers
19 views

How do I find at least the closest penetrating point with SAT? [duplicate]

For more accurate simulations, I want to find the closest point of another polygon to one polygon's center when they collide. Is this possible with the SAT algorithm? Is it a good strategy at all for ...
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votes
1answer
69 views

How do I calculate force from collision between 2 rigidbodies in 2D?

I have a physics engine based on the Game Physics Engine Development by Ian Millington. In chapter 7.1.1, it provides the formula: V = (pA.Velocity - pB.Velocity) * (pA - pB).normalized where V is ...
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votes
1answer
78 views

wheeled 2D character controller platform edges problem

I have built a little wheeled 2D character controller (a rectangle for the body and a circle for the legs with a motor joint). Everything is ok but the problem is that when the player reaches the edge ...
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0answers
164 views

(LibGDX/JAVA) How can I get a rectangle to rotate with this pendulum so I can start detecting collisions?

One of the objects in my game is a pendulum that swings in a semi-circle. This is done by having an update() method like this: public void update() { angleAcceleration = +1.81 / length * ...
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2answers
318 views

Moving one object from one point to another with acceleration

How would someone implement moving an object from one point in 2D space to another using these formulae to update objects: m_position.setX/Y( m_position.X/Y() + m_velocity.X/Y() * dt + 0.5 * m_acc * ...
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3answers
131 views

Calculate intersect point / aim point

I'm working on a simple game, and I need to calculate the position to aim. Since my math days are a bit behind me, I put together a simple example to illustrate: So given that I know the position ...
2
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2answers
152 views

Why doesn't this 2d physics calculation yield the desired jump height?

I found a formula for gravity and jumping in this article: http://error454.com/2013/10/23/platformer-physics-101-and-the-3-fundamental-equations-of-platformers/ I implemented this formula and ...
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votes
2answers
64 views

unity2D Top-Dow Mobile rigibody2D

im using this code for my 2D TopDown mobile player movement.but when i move player With UI Image buttons player keep moving.it didnt stop.and also player starting of move he is very slow. the he ...
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0answers
159 views

Rain World : How to have intelligent movement / animation?

In the project RainWorld the characters seem to move "intelligently" as they move "unrestricted". They seem to know "how" to move their limbs and "what" needs to be done. Here for an example the ...
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2answers
262 views

Leapfrog integration vs Euler integrator

I am looking at various integration methods for my n-body simulation and I'm slightly confused about actual implementation of leapfrog integration. According to the wikipedia page leapfrog method is ...
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vote
1answer
611 views

Is there a javascript physics engine that does not require canvas? [closed]

I just need a really simple and small physics engine for squares or circles that moves images using javascript. For the project that I am working on, I can't use canvas, so I will be moving the images ...
2
votes
2answers
1k views

Can Unity 5 or Unreal Engine 4 do computationally identical physics simulation across platforms?

In order to use certain approaches to multiplayer physics, it requires that the clients calculate exactly the same values for physics simulations. That "exactly" is a very big word here and goes all ...
0
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1answer
971 views

Unity 2D - Pixel perfect movement using physics

I'm trying to make a game in the style of many NES games and I'd like object movement to do two things: I want to move an exact number of pixels per update. I want, for lack of a better term, ...
0
votes
1answer
69 views

How to use friction to bring object to a stop in a simple 2D platformer?

I'm coding the physics for a little platformer I'm making but I'm not sure how to design a friction calculation that does what I expect. When running along a platform I want the player's character to ...
1
vote
1answer
133 views

CGVectorMake to move SKNode at a certain speed towards the middle of screen?

I am trying to launch my ball sprite towards the middle of the screen at the same speed every time I launch it. let vel: CGFloat = 1000 dx = size.width / 2 - ball.position.x dy = vel - size.height / ...
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4answers
76 views

How do I figure out if a point is infront or behind my vehicle?

I need to figure out whether a point is infront or behind my vehicle. I have the vector of it's position, forward direction. So far I have tried finding the vector perpendicular to its forward ...
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votes
2answers
209 views

Moving OBB vs. triangle intersection test

Requirements: to write a test function that, given a moving OBB (oriented bounding box) and a triangle, returns true whenever the OBB hits the triangle. The OBB is described by its half extents (h1, ...
0
votes
1answer
83 views

Spherical Collision

I have a made spherical collision system which creates a major problem, the balls gets stuck to each other on high speed and sometime with low speed collisions. I researched a lot but I couldn't found ...
1
vote
0answers
164 views

How do I implement realistic recovery from weapon recoil?

I want to create an equation determining how fast a gun recovers back to its center after it has fired. I have a weapon system functioning based on constants (recoil amount, bullet spread, etc.) ...
1
vote
1answer
299 views

Estimate the time it takes for an object to travel from point A to point B

I have an object with vec2 position, velocity, and destination with 2 variables maxspeed and acceleration. In each step, its position is calculated as follows: vec2 desiredVel = destination - ...
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2answers
83 views

Gravity Simulation failing at short distances

I have a 2D space simulation with gravity acting on three bodies (e.g. sun and 2x planets). The simulation seems pretty stable with RK4 (was unstable with Euler). The problem arises if the orbit of ...
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0answers
18 views

How can I track a leader vehicle at a specific angle and distance?

I am using Matlab and have code which allows a vehicle to find its way to certain coordinates chosen by the user. I now want to add a second vehicle which stays fixed at a specific distance and angle ...
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0answers
188 views

Physics2D.OverlapCircleAll seems to be bigger than my radius

Im trying to make a "Scorched earth"-like game using unity. I managed to fire my bullet and make it explode on contact. What I am trying to do is do some damage to the tanks even if the bullet didn't ...