A mathematical concept that can be used to express position, direction or velocity and which can simplify or outright trivialise spatial problems.

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3answers
528 views

How does this circle collision detection math work?

I'm going through the wildbunny blog to learn about collision detection. I'm confused about how the vectors he's talking about come into play. Here's the part that confuses me: p = ||A-B|| – ...
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1answer
260 views

Calculating projectile velocity from moving object

I'm working on a top down space shooter and am having trouble with calculating/understanding the physics for projectiles launched from the space ship. The ships have a velocity vector and a turret ...
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1answer
195 views

When to use an Array vs When to use a Vector, when dealing with GameObjects?

I understand that from other answers, Arrays and Vectors are the best choices. Many on SE claim that Linked Lists and Maps are bad for video game programming. I understand that for the most part, I ...
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2answers
121 views

matrix to rotate a vector to a known arbitrary axis

Let's say I have a vector V (v.x,v.y,v.z) which is normalized and points somewhere in 3d space. And that I have another vector Z of (0,0,1). Knowing only these two things I'm looking for a ...
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1answer
106 views

Does a 2D Vector or 2x2 Matrix play any role in 2D Transformations?

I'm having trouble trying to figure out if a vec2 or mat2 class are used at all in transformations for 2D rendering. Vec2, apart from representing UVs, AFAIK, is relatively pointless in regards to ...
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2answers
459 views

What is the camera direction vector for an isometric view?

What values correspond to a 3D vector for screen-normal from within an isometric game? It needs to be in game coordinates. It is a standard isometric where tiles are rotated 45 degrees and half ...
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2answers
804 views

Libgdx: Am I abusing Vector2? Is there a better way to do my position updates and rendering?

I'm simulating hair in a game. Currently I have a HairField object, which has a position defined by a Vector2. Each HairField has multiple Hair objects in a list, each with a position defined by a ...
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1answer
814 views

Rotate triangle so that its tip points in the direction of the point on the screen that we last touched

OpenGL ES - Android. Hello all, I am unable to rotate the triangle accordingly in such a way that its tip always points to my finger. What i did : Constructed a triangle in by GL.GL_TRIANGLES. Added ...
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1answer
67 views

Reflection velocity

I'm trying to get a moving circular object to bounce (elastically) off of an immovable circular object. Am I doing this right? (The results look right, but I hate to trust that alone, and I can't ...
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1answer
62 views

Eculidean space and vector magnitude

Below we have distances from the origin calculated in two different ways, giving the Euclidean distance, the Manhattan distance and the Chebyshev distance. Euclidean distance is what we use to ...
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2answers
204 views

How can I project a vector on another vector?

I have a generic not normalized Vector3 v1 and I want to calculate its component along another Vector3 v2. I used to normalize the vector I want to be the direction and then multiplying the other ...
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1answer
163 views

Confusing with an articles wording on Clamping a Vector2

I have been reading an article on Collision Detection and how to resolve it. http://www.wildbunny.co.uk/blog/2011/04/20/collision-detection-for-dummies/ In the section describing an AABB vs Circle, ...
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1answer
1k views

Unity: parallel vectors and cross product, how to compare vectors

I read this post explaining a method to understand if the angle between 2 given vectors and the normal to the plane described by them, is clockwise or anticlockwise: public static AngleDir ...
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1answer
938 views

Interpolation between two 3D points?

I'm working with some splines which define a path a character follows (you can see a gameplay video here to get a better understanding of what's going on: http://www.youtube.com/watch?v=BndobjOiZ6g). ...
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4answers
191 views

Vectors and corners of squares

I am having some problems with some vector math. Imagine a square and coming from each corner of the square is an invisible vector, which starts at the square's centre and ends at the edge of the ...
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1answer
2k views

how to create a Quaternion from an Orientation Vector in xna

i have a Vector3 represents an Orientation in 3D , how to convert it to the corresponding Quaternion ? is there any quick way ? EDIT : i want to add an angular velocity vector to the Orientation ...
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3answers
511 views

Get intersection of vector in the middle of the screen

My screen resolution is 640x480 and I have two Vector2 objects located at (10,10) and (600, 320). How can I connect these two objects and extend the line to encompass the whole screens width, how can ...
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2answers
67 views

How to get the normal that points *out* of a polygon

In 2D, each vector (x, y) has two normals: (-y, x) and (y, -x), pointing in opposite directions. Say I have a polygon and for each of it's edges I need to get the normal pointing outwards. In the ...
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2answers
167 views

Adding an angle variance to a 3d vector

I am converting a particle emitter from 2d to 3d. In the 2d system the original coder used a random angle variance and added it to the angle. So it would be something like: thisAngle = emitterAngle ...
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1answer
95 views

3D vector graphics - maintaining correct Z 'length'

So I'm trying to build myself a 3D display 'engine', or whatever it ought to be called. I've been experimenting with PyGame, as it's familiar to me. In a way this has almost been more an excuse to ...
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2answers
135 views

Twitchy sprite movement

I'm having an issue with sprite movement, and I'm not sure how to deal with it. When I set a destination for my player sprite (by clicking the screen), it sets the player moving in that direction. ...
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1answer
242 views

How to simulate acceleration and then deceleration?

Currently I am only using deceleration. Here is how I do it I need to cover Vector(x,y) unit distance to reach B from A. I simply do - rendering loop-> position = A + Vector(x,y).scale(factor); ...
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1answer
603 views

how can i get rotation vector from matrix4x4 in xna?

i want to get rotation vector from matrix to realize some parent-children system for models. Matrix bonePos = link.Bone.Transform * World; Matrix m = Matrix.CreateTranslation(link.Offset) * ...
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1answer
253 views

Viewport.Unproject - Checking if a model intersects a large sprite

Let's say I have a sprite, drawn like this: spriteBatch.Draw(levelCannons[i].texture, levelCannons[i].position, null, alpha, levelCannons[i].rotation, Vector2.Zero, scale, SpriteEffects.None, 0); ...
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1answer
2k views

Vector movement in space type game (Mouse rotation)

I'm having an issue with my movement in my 'game' prototype. It's basically not working and admittedly my knowledge with vectors is lacking. The issue I'm running into is that the ship won't move in ...
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1answer
533 views

Trouble with SAT style vector projection in C#/XNA

Simply put I'm having a hard time working out how to work with XNA's Vector2 types while maintaining spatial considerations. I'm working with separating axis theorem and trying to project vectors onto ...
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1answer
161 views

Moving in an arc using Vector3

I'm trying to get this object to move right across the screen until it gets close to the center and arc down smoothly into a straight downward movement. Here's what I've tried: if (position.X < ...
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1answer
276 views

XNA - Incorrect Mouse Ray?

I have the following code: Vector3 nearSource = new Vector3(mState.X, mState.Y, 0.0f); Vector3 farSource = new Vector3(mState.X, mState.Y, 3.0f); Vector3 nearPoint = ...
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1answer
124 views

How should I update vectors, et cetera, in a time-based fashion?

I'm trying to write something I believe is straightforward but wanted to check that I'm doing it right. All I want is to update the position of a 2D sprite based an acceleration and velocity. I'm ...
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1answer
237 views

What can I use to generate 2d vector graphics as a list of coordinates?

I am working on a game that uses simple 2d vector graphics. I want a tool that will let me visually draw things like arbitrary polygons by placing points. A perfect tool would present a grid that I ...
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1answer
145 views

Unity: Rolling a ball around a spherical planet with forces

I'm trying to make a game in Unity where the player character is a ball (a sphere), and the game world is a planet (a very large sphere) that the ball can roll around on. The ball can be rolled in any ...
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1answer
81 views

How do I make a sprite move to another position using vectors

Ok, so far I have made the sprite move to a mouse position. But I got a question, does anyone know how to make a sprite move by itself without the use of a mouseclick from Point a to point b using ...
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1answer
140 views

Spaceship acceleration for following waypoints

I'm creating a turn based space ship strategy game with simultaneous turn resolution similar to Steam Birds. After all the orders are given, the ships run through a real time simulation where they ...
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1answer
49 views

How to rotate vector A around another vector B?

Lets say I know what is directly above a turret. I also know where the turrets gun is currently pointing. I would like to know where will the turret's gun will point if I rotate it. I suppose I could ...
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3answers
365 views

How to move an object along a vector

Let's say I got an object A and object B in a 2D game. I create a vector leading from A to B. It's name is AB. How can I make A move along the vector AB and reach B? One way I was thinking of doing ...
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1answer
435 views

View to normal calculation in GLSL

Sorry for the terrible title, but I really cant think of anything better.. Suggestions welcome. I am trying to do something like showcased in this video: http://www.youtube.com/watch?v=CaTI2d0tQME ...
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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, ...
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1answer
237 views

Converting 3 axis vectors to a rotation matrix [closed]

I am trying to get a rotation matrix (in 3dsmax) from 3 vectors that form an axis (all 3 vectors are aligned by 90 degrees each other) Somewhere I read that I could build a rotation matrix just by ...
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1answer
119 views

Explaining vector problem

I'm trying to simulate a centipede game, and I'm doing the snake movement. I have seen that piece of code, but can't get it, I know it gets the different between the current, previou's nodes ...
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1answer
116 views

Movement constrained to the faces of a cube

The basic setup I'm working with is a cube rendered in-Engine (Panda3d, although I only am looking for a generalized solution) as well as a 2d square on one face of the cube. The eventual outcome I'm ...
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1answer
367 views

How do I get the axes for SAT collision detection

In SAT collision detection how do I calculate the axes for projection?
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2answers
254 views

Billboarding + aligning with velocity direction

I'm working on a particle system where I'm orientating the billboard using the inverted orientation matrix of my camera. This works quite well and my quad are rotated correctly towards the camera. ...
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1answer
490 views

Transform 3d viewport vector to 2d vector

I am playing around with 3d transformations and came along an issue. I have a 3d vector already within the viewport and need to transform it to a 2d vector. (let's say my screen is 10x10) Does that ...
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1answer
334 views

How to prevent 2D camera rotation if it would violate the bounds of the camera?

I'm working on a Camera class and I have a rectangle field named Bounds that determines the bounds of the camera. I have it working for zooming and moving the camera so that the camera cannot exit its ...
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1answer
683 views

How do I get the vertical angle between 2 vectors?

So I'm modding a 3D game, my goal is to place a label on the screen pointing to the unit's direction. I'm getting the horizontal angle by projecting these vectors in a plane, like this: private ...
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1answer
196 views

Mesh to world vector translation

Suppose I have a world defined in typical OpenGL coords.. then the up vector defined for this space is (0,1,0). Now, if I load a model that is defined with (0,0,1) as its up vector, what are the ...
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0answers
54 views

unity3d-Find angle between 3 vector3 points obtained from swipe

I was trying to find the angle between 3 vector3 points obtained from the screen swipe. The first vector3 point is the first touch position fp, the second is some intermediate touch ip and the third, ...
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1answer
108 views

Spritekit - gradually apply force vector in different direction (space ship turning)

I have a space ship that I'm applying a force vector to using a joystick for control. I would like this to smoothly fly around when I'm switching directions.. Exactly like minisquadron if you've ...
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0answers
221 views

(Libgdx) Move Vector2 along angle?

I have seen several answers on here about moving along angle, but I can't seem to get this to work properly for me and I am new to LibGDX... just trying to learn. These are my Vector2's that I am ...
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0answers
103 views

Rotate Points with Object in world space

I posted this in the original stack overflow then realized that a game-dev specific one exists. I am working on personal project that requires me to have 4 points surrounding an object (1 at each of ...