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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2
votes
1answer
63 views

Get a random vector

I'm trying to make a small pariticle-like simulation, and I'm trying to make each parrticle go a random direction from one point (mouse pos). The problem is I don't know how to get the random vector ...
-2
votes
2answers
316 views

Convert atan2 value to standard 360-degree-system value [duplicate]

Lets say I'm using atan2 to get the angle between two vectors. atan2 gives a value in radians. I convert it to degrees using a built in function in Java. This gives me a value between 0 and 180 ...
-2
votes
1answer
170 views

How does atan2 work when getting angle of a vector?

I know that atan2 gives me the absolute angle of any vector. But it doesn't give a value from 0 to 360 degrees. Instead, it gives a value (if I'm not mistaken), between 0 and 180, or between 0 and ...
0
votes
1answer
429 views

Using atan2 to calculate angle between two vectors

I understand that: atan2(vector.y, vector.x) = the angle between the vector and the X axis. But I wanted to know how to get the angle between two vectors using atan2. So I came across this solution: ...
1
vote
1answer
93 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 ...
1
vote
3answers
323 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 ...
4
votes
2answers
576 views

How do I use the dot product to get an angle between two vectors?

I am learning to use normalized vectors in my games. I've learned that in order to know the angle between two vectors, I can use the dot product. This gives me a value between -1 and 1, where 1 ...
-1
votes
3answers
1k views

Move player to mouse click

Im hopelessly not good at algebra and such. But im trying to learn. I want to learn and understand how to use it in game programming rather than modifying snippets or using classes that do it for me. ...
2
votes
4answers
2k views

How can I implement a directional melee attack?

I am attempting to make a top down game similar to the SNES Zelda games, in Unity 4.3, in 2D. When my character swings their sword, every enemy within a radius takes damage. I want to make sure that ...
0
votes
1answer
46 views

What does it mean to cross a scalar with a vector in a 2D plane?

At the moment, I'm following this page to create a physics engine. As per that page, I need to cross angular velocity by a distance vector to get relative torque and such, but I'm not sure how (in a ...
2
votes
1answer
109 views

How do I compute the point of a triangle-ray intersection?

I have a line (the direction vector of the player) and a triangle representing the face of a model (so composed of 3 points). I can't find the mathematical operation to check if that vector is ...
10
votes
2answers
569 views

Shooting the bullet out of the gun instead of the camera, yet keeping it accurate with respect to the reticle

I'm working on a first person game, and I've ran into a problem. In my game, there's the player's gun being rendered, as well as a reticle in the center of the screen - like this: First, Let's ...
0
votes
1answer
100 views

Creating a textured object infront of the current character in unity 3d

I've spent about half a day trying to get my head round this and i'm not having too much luck, essentially what I want to do is play an animation and then once the animation has finished create a flat ...
0
votes
1answer
61 views

How to modify normal vectors with a tranformation matrix

Transformation is quite simple when it comes to Position or Color of the vertex, for Position just multiply matrix * vector and for color just don't do anything, but my question now is: How to handle ...
0
votes
1answer
80 views

How do I lock drawn lines to be orthogonal to an existing one?

I'm making a 2D game in Corona for Android/iPhone that is similar to Volfied. In my game, the user has to touch the screen to draw a line for the character to move along. How can I force the lines to ...
3
votes
4answers
262 views

Why not use vectors to represent orientation?

From what I've read, people mostly use either quaternions or 3x3 matrices to represent 3D orientations, while plain vectors are used for angular velocity/momentum. Since we can use vectors to ...
1
vote
1answer
105 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 ...
1
vote
2answers
303 views

Detecting walls or floors in pygame

I am trying to make bullets bounce of walls, but I can't figure out how to correctly do the collision detection. What I am currently doing is iterating through all the solid blocks and if the bullet ...
2
votes
1answer
240 views

Rotate Camera as an Object Manoeuvres

There are loads of questions (all of which I have looked at) on here about cameras following objects. Using them, I have successfully got my camera to follow my car when driving, but I am unable to ...
-1
votes
1answer
90 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 ...
0
votes
1answer
182 views

Circle-Rectangle collision velocity adjustment

I created my circle vs. rectangle method based on this algorithm: http://stackoverflow.com/questions/401847/circle-rectangle-collision-detection-intersection Currently, I have a dynamic ball with ...
1
vote
1answer
418 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 ...
1
vote
1answer
989 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
0answers
64 views

Using Angles (or rotation) with Vectors for Car physics

I've been reading this blog that explains basic linear algebra for game developers and I understand the basics of vector mathematics. I'm using vectors to create a car that simulates the very basic ...
0
votes
1answer
192 views

Make Gameobject Stand On Surface Facing Certain Direction

I want to make a biped character stand on any surface I click on. Surfaces have up vectors of any of positive or negative X,Y,Z. So imagine a cube with each face being a gameobject whose up vector ...
1
vote
1answer
220 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 ...
2
votes
1answer
238 views

Vector normalization gives very imprecise results

When I normalize vectors I receive very strange results. The lengths of the normalized vectors range from 1.0 to almost 1.5. The functions are all written by me, but I just can't find a mistake in my ...
2
votes
4answers
232 views

How do I rotate a camera around the Y axis of the object it's looking at? [duplicate]

I'm making a camera that can currently rotate freely from the back to the front of a target object by giving it an angle and a distance. I do the above with the following code directionVector = ...
19
votes
3answers
919 views

What's so different/complicated/useful about vectors?

Forgive me if this isn't considered a real question, but it is something I am genuinely confused about. I constantly hear other game developers talk about how using vectors are very useful, but also ...
3
votes
4answers
284 views

How do I find the 2D direction to a 3D location?

I'm writing a 3D space flightsim, and I'm trying to display a 2D arrow on screen that points to the player's selected target. To clarify, the arrow needs to point in the direction that the player has ...
0
votes
0answers
99 views

Bouncing objects against the side of the screen

I want to have certain circular objects bounce against all four sides of the screen. After searching a lot on the internet, I found the following formula: Vout = Vin - ((1+e) *dot(Vnormal, Vin) * ...
5
votes
3answers
596 views

Why is this code producing jittery movement?

I have a new project, all settings default with a simple cube on a plane. Cube is not kinematic but is a rigid body under the effects of gravity. I'm trying to normalize the direction before I ...
1
vote
2answers
441 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 ...
0
votes
0answers
221 views

Finding a normal vector

I'm trying to replace my old integer based movement and collision system with a vector system, because its more precise and more flexible. I want to implement wall sliding, such that if a player hits ...
1
vote
2answers
133 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. ...
3
votes
1answer
119 views

How to calculate where specular highlights converge with an anisotropic shader?

If you look at a rendering with an anisotropic shader applied you will notice that there are special spots on the 3D surface/mesh where the lights seems to converge, a point where a given vector ...
1
vote
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 ...
14
votes
5answers
716 views

Can I simplify the inequality “distance(p1, p2) < distance(p1, p3)?”

I am working on some vector logic, so am asking: can I save processor time by simplifying this inequality: distance(vector1, vector2) < distance(vector1, vector3) I see that vector1 is repeated ...
0
votes
0answers
28 views

Move object forward based on it's direction(1D rotation) [duplicate]

I have 2D game where I want my object to move forward based on it's direction. This is what I've tried: position.x+=Math.Cos(rotation)*speed; position.y+=Math.Sin(rotation)*speed; However this ...
2
votes
1answer
243 views

How to correctly represent a bone system?

I'm currently representing my bone system as follows, in pseudocode: root = {} root.rot = v3(0,0,0) root.pos = v3(0,0,0) function create_child(parent,rot,length): child_bone = {} ...
0
votes
0answers
235 views

Space Strategy Ship Movement Math

This is similar to a question I asked a while ago, but I phrased it so terribly so might as well start over. I am trying to implement ship movement in 3D space, but confined to a 2D plane at y=0 (see ...
0
votes
2answers
316 views

How do I calculate speed given two xy vectors?

I have some code that returns the x and y linear velocities of a moving space ship. How can I combine these to give me total speed? x = self.player._box2dBody.GetLinearVelocity().x; y = ...
1
vote
1answer
233 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); ...
0
votes
1answer
106 views

2D vector to Quaternion

I have a 2D vector (with only X and Y), and my engine only supports orientation through Quaternions. How do I translate a 2D vector to a quaternion? The X and Y represent the direction (so X = 0 ...
2
votes
3answers
1k views

How to find the entity I'm looking at?

I am currently making a mod for Minecraft but I have come to a stop because I am lacking in some knowledge. I need to get data for the entity I am looking at, which I believe requires the use vectors, ...
-2
votes
1answer
94 views

2D Vector Compass Direction [duplicate]

Relating to this question; What's the best way of translating a 2D vector into the closest 8-way compass direction? My query is if this would work in the following order(below) and if so, how ...
3
votes
1answer
141 views

Moving sprite from one vector to the other

I'm developing a game where enemy can shoot bullets towards the player. I'm using 2 vector that is normalized later to determine where the bullets will go. Here is the code where enemy shoots: ...
5
votes
1answer
147 views

Vector Math question

Suppose I have two game object located at two Vector3s v1 and v2, respectively. If I wanted to locate a position between v1 ad v2, but 3 units away from v2, how would I manage that in terms of ...
1
vote
1answer
251 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 ...
0
votes
2answers
167 views

Finding vectors with two points

We're are trying to get the direction of a projectile but we can't find out how For example: [1,1] will go SE [1,-1] will go NE [-1,-1] will go NW and [-1,1] will go SW we need an equation of ...