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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2k views

Getting correct angles between Vector3s

I'm working on a project where you can draw lines between points. You select one point and drag the mouse onto another point and a line is drawn between them. The line itself is a 3d object which is ...
3
votes
1answer
350 views

How do I implement a selectable world map?

I want to have a selectable map of the world, preferably zoomable, in a cocos2d project. When I tap on a country, I want that country to be selected so that I can perform some other operations with ...
3
votes
1answer
497 views

Finding closest object to a location within a specific perpendicular distance to direction vector

I have a location and a direction vector indicating facing, I want to find the closest object to that location that is within some tolerance distance (perpendicular distance) to the ray formed by the ...
3
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1answer
327 views

Vector fields and game engine

It exist a game developed with a vectorfield game engine? What I mean is that instead of calculating intersections, one could calculate the vector field generated for example by gravity, and for ...
2
votes
3answers
4k views

Get points on a line between two points

I'm making a simple space game in JavaScript, but now I've hit a wall regarding vectors. The game view is top-down on a 2d grid. When the user clicks on the grid, the space ship will fly to that ...
2
votes
2answers
399 views

Why does handedness matter at all?

I'm really trying to understand this from a mathematical viewpoint. After all, numbers are numbers, the chirality or handedness depends on how one interprets it. Say I've three basis vectors x (1, 0, ...
2
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2answers
1k views

convert orientation vec3 to a rotation matrix

I've got a normalized vec3 that represents an orientation. Each frame of animation, an object's orientation changes slightly, so I add a delta vector to the orientation vector and then normalize to ...
2
votes
3answers
2k views

Check if the vector is behind another or maybe opposite directions?

I'm doing a network game and on the client side, i interpolate the client position with the server sent extrapolated position. The client has its own physics simulation wich is corrected by the server ...
2
votes
1answer
427 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
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2answers
96 views

How to convert non-discreate data for discreate pathfinding?

I have a list of entities that looks like [{x,y,width,height}, {x,y,width,height}, ...]. This list is non-discreate, It doesn't follow a grid. entities can be positioned at floats like x:2.345 Most ...
2
votes
3answers
2k views

Converting Degrees to X and Y Coordinate change

I am using a float positioning system in my game. IE float x,y,z now I want to get the location of the mouse, then to fire an arrow to it. X0 = the players X location X1 = the mouse X location Y0 = ...
2
votes
2answers
2k views

Smooth vector based jump

I started working on Wolfire's mathematics tutorials. I got the jumping working well using a step by step system, where you press a button and the cube moves to the next point on the jumping curve. ...
2
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4answers
3k views

How to detect if object is moving in clockwise- or counterclockwise direction?

I've read this one, but I need more info: rotating an object from sourceAngle to destAngle, both 0-359, clockwise or counter clockwise? I have a ball. The user is able to drag the ball in any ...
2
votes
2answers
1k views

Why does my sprite jitter when it arrives at its destination?

I have just started looking into XNA for WP7 - and I am definitely the sort of person who likes to find answers to my questions without begging for help! I searched here to find an answer but I found ...
2
votes
1answer
456 views

Min/Max of two vectors?

This seems like a simple question, but i'm having trouble searching the internet for it. In XNA, during a collision detecting method, I would determin the minimum of some vectors. // Get the minimum ...
2
votes
1answer
329 views

What is Vector Projection and what is it's use in games?

Couldn't find a clear enough answer on Google. I know what vectors are. But what does it mean to project a vector onto another, and what is it used for in games?
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votes
3answers
1k views

Oriented Bounding Box - How to?

I've been trying to write my own collision code, less because I want to, more because I want to understand its working. To do this, i've been working off of the popular collision book i'm sure you've ...
2
votes
2answers
1k views

Determining if something is on the right or left side of an object?

I have a character in a 3D world which is facing an arbitrary direction on a flat plane, the player can click on the left or right side of the character and based on which side is clicked on a ...
2
votes
1answer
285 views

What is wrong with my technique for transmitting server and client game state?

I'm doing a network implementation of a fast-paced game. I have a puck on bot the server and client side of the simulation. I want to update the client puck position only if they are on the same ...
2
votes
2answers
432 views

Swapping axis labels between 2D and 3D coordinates

My game world is 3D. The map is only 2D, however. It is natural to think of the map as having an X and Y axis. And it is natural to think of the world has having an X, Y and Z axis, where Y is ...
2
votes
1answer
4k views

Adding 2D vector movement with rotation applied

I am trying to apply a slight sine wave movement to objects that float around the screen to make them a little more interesting. I would like to apply this to the objects so that they oscillate from ...
2
votes
2answers
560 views

Intelligently move aircraft using curves

I am trying to code a script to move an aircraft entity from point A to point B and at some point in the middle of moving have the aircraft forward vector face Point C (to fire a missile at an enemy ...
2
votes
4answers
2k 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
2answers
791 views

android 2d bullet-spawn (shooting)

This will be a quick question since Im pretty sure I'm overlooking something small that I for some reason cant see. My sprite is moved using a joystick, and I want my sprite to be able to shoot. I've ...
2
votes
2answers
846 views

How to calculate vector that is perpendicular to the direction of moving in Flash?

In flash i have a class that extends movieclip and i am moving it forward, up and down, and rotating it. How can i calculate the vector that is perpendicular to this movieclip?
2
votes
1answer
161 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 ...
2
votes
1answer
332 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 ...
2
votes
4answers
306 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 = ...
2
votes
2answers
207 views

How can I move a polygon edge 1 unit away from the center?

Let's say I have a polygon class that is represented by a list of vector classes as vertices, like so: var Vector = function(x, y) { this.x = x; this.y = y; }, Polygon = function(vectors) { ...
2
votes
1answer
397 views

Detect if square in grid is within a diamond shape

So I have a game in which basically everything is a square inside a big grid. It's easy to check if a square is inside a box whose center is another square: *** x *o* --> x is not in o's ...
2
votes
1answer
308 views

Moving Unit Parallel to Mouse in TBS Game

I'm writing a basic Turn-Based Strategy game using Unity3D. It's not grid-based. I've come to the point where I'm coding unit movement, and I'm having trouble figuring out how far to move the units ...
2
votes
1answer
527 views

multiply matrix by vector: what to do if need to change y-up to z-up?

I multiply a matrix with a position vector to get a new position, however, now I need to change my matrix from y-up coordinate space to z-up. Changing only the matrix won't work: how to apply the ...
2
votes
1answer
204 views

Calculate the direction, From Outer Polygon Point to Inner Polygon inside Point

I was able to find the co-ordinates of inner Polygon using this trick. Need the co-ordinates of innerPolygon But, I have some problem in getting the direction from Outer Polygon Point to Inner ...
2
votes
1answer
526 views

Calculate the initial velocity of a 3D trajectory

I've got a 2D projectile code sample working, but would like to extend it to 3D. How would I calculate the initial velocity of the Z-axis? At the moment, I've got: initVel.X = (float)Math.Cos(45.0); ...
2
votes
2answers
115 views

Opengl Quad Tessellation Control Shader

I have the generic tessellation evaluation shader for triangles but I need to make it work for quads. Is there any chance someone could explain what is happening here and point me in the right ...
2
votes
1answer
109 views

Libgdx : point that scrolls on the edge of a circle

I'm not very familiar with libgdx vectors. I want to create my own joystick-controller and I want to know how can I find the coordinates of B by using Vectors. I can calculate the radius and I have ...
2
votes
2answers
33 views

Derive direction in which a spot light emites its light from a projection matrix

First of all, sorry if my question sounds too basic or even makes no sense. I'm new with game development I'm working with HPL1Engine, specifically, the lights parts. I need to know the direction in ...
2
votes
1answer
70 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
1answer
683 views

2D Top down acceleration vector

I have been wanting to solve the issue of movement once and for all... with all that I have learnt and read through, should be a piece of cake one would have thought... , seems it isn't. Having ...
2
votes
1answer
419 views

Shooting Bullets Around a Sphere

I currently have a ship that can orbit around a sphere freely controlled by a joystick. There is a separate joystick that controls the gun and starts shooting when it is touched. Right now the ...
2
votes
1answer
277 views

Turning to face mouse

Given three points on the same Y plane; A ship A point along the ships heading A mouse cursor How can I find which direction and angle the mouse cursor is from the ships heading? I have a limited ...
2
votes
1answer
478 views

android game-logic for shooter

Im creating a 2d game for android. I'll just get right to it. I have a sprite controlled by a joystick that needs to shoot, sofar Ive managed to get direction and movement on my bullet, but then I ...
2
votes
1answer
208 views

XNA Framework sprite vectors and also scaling

I'm working on making my first Pong game with XNA Framework 4.0. Right now i've put 2 pong paddles and a ball (they have separate classes). In the "Paddle" class i've made a function that returns a ...
2
votes
1answer
939 views

Rotating a vector by a quaternion

I am trying to rotate a direction vector (0,0,1,0) by a rotation quaternion in DirectX. From what understanding, to rotate the vector you must do NewVector = rotQuaternion * Vector * ...
2
votes
1answer
4k views

2d tank movement and turret solution

I'm making a simple top-down tank game on the ipad where the user controls the movement of the tank with the left "joystick" and the rotation of the turret with the right one. I've spent several hours ...
2
votes
1answer
272 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 = {} ...
2
votes
1answer
180 views

front and back face detection

I am trying to implement a dynamic shadow system for a 2d game using this tutorial : ...
2
votes
2answers
759 views

Relative cam movement and momentum on arbitrary surface

I have been working on a game for quite long, think sonic classic physics in 3D or tony hawk psx, with unity3D. However I'm stuck at the most fundamental aspect of movement. The requirement is that I ...
2
votes
1answer
246 views

How to shift a vector based on the rotation of another vector?

I’m learning 2D programming, so excuse my approximations, and please, don’t hesitate to correct me. I am just trying to fire a bullet from a player. I’m using HTML canvas (top left origin). Here is a ...
2
votes
1answer
355 views

Transform 3D vectors between coordinate systems

I've got 6 points in 3D space: A,B,C,D,E,F, that represent 4 vectors. AB is perpendicular to AC and DE is perpendicular to DF. I need to find a transformation matrix M, that transforms AB to DE and ...