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
555 views

When to return a reference and when to return a copy?

I was looking at the d3dx math .h and noticed that a difference between the "+" and "+=" operators: D3DXVECTOR3& operator += ( CONST D3DXVECTOR3& ); D3DXVECTOR3 operator + ( CONST ...
3
votes
1answer
577 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?
3
votes
4answers
402 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 ...
3
votes
1answer
2k views

Make objects follow a strict path (Xna)

I am making a defence game. Naturally, this means that there needs to be objects following a path on the screen. I want to make it a strict path from one point to another to another. I could use an ...
3
votes
2answers
549 views

3D rotation matrices deform object while rotating

I'm writing a small 3D renderer (using an orthographic projection right now). I've run into some trouble with my 3D rotation matrices. They seem to squeeze my 3D object (a box primitive) at certain ...
3
votes
2answers
102 views

Need the co-ordinates of innerPolygon

Let say I have this diagram, Given that i have all the co-ordinates of outer polygon and the distance between inner and outer polygon is d is also given. How to calculate the inner polygon ...
3
votes
1answer
201 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 ...
3
votes
1answer
145 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: ...
3
votes
1answer
186 views

How to make an object stay relative to another object

In the following example there is a guy and a boat. They have both a position, orientation and velocity. The guy is standing on the shore and would like to board. He changes his position so he is ...
3
votes
3answers
4k views

Vector images (SVG or other formats) support in libgdx or other Android framework? [closed]

I'm looking for a website to create games for Android. I'm interested in something that supports vector images. Do you know if libgdx supports them or is there a convenient way to use them in libgdx? ...
3
votes
2answers
2k views

Weird rotation problem

I'm creating a simple tank game. No matter what I do, the turret keeps facing the target with it's side. I just can't figure out how to turn it 90 degrees in Y once so it faces it correctly. I've ...
3
votes
1answer
57 views

Finding coordinate in radius

Hello i have two points (Vector3) A and B. And have a radius r How can i find a coords of point P in a circle by angle?
3
votes
1answer
174 views

Endless Running Game - Changing Lane Function in JAVA

I am developing a kind of vertical endless running game, where the character has 4 possible lanes to be in. I am using libGDX and want the character to change lanes by adding a horizontal velocity to ...
3
votes
5answers
558 views

Is there a quick way to determine if a vector is in a quadrant?

I am wondering if there is a quick easy way to determine if a given vector is in a specified quadrant. In the below image, I've define the ranges of the blue quadrants. For example, if I am given ...
3
votes
1answer
227 views

front and back face detection

I am trying to implement a dynamic shadow system for a 2d game using this tutorial : ...
3
votes
2answers
628 views

what does AngleVectors method in quake 3 source code does

I just downloaded quake 3 for learning purposes. I know some of some linear algebra(basic vector math ie: dot,cross product). However I can't decipher what below method does, I know what is yaw,pitch ...
3
votes
1answer
431 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 ...
3
votes
2answers
311 views

calculating torque from angular momentum considering inertia moment

so I am trying to determine exactly how much torque to apply to a 3d model to make it rotate at a particular rate. I apply force from the location of each engine on the craft so if one breaks the ...
3
votes
1answer
132 views

Edit spawn location according to vector direction

I'm trying to make a turret in Bukkit (Java). This will shoot an arrow to the players that are in the shooting radius. But now I've a little problem, the arrow gets stuck inside the block where its ...
3
votes
1answer
3k views

Orthographic Camera and Raycasting in Three.js

I'm working on a test project porting a simple game from iOS to Javascript. I've got the orthographic camera working and it can view the objects in the scene and move up and down the tower of meshes ...
3
votes
3answers
4k 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
408 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
622 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
votes
1answer
366 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 ...
3
votes
1answer
316 views

Controlling roll rotation when travelling along bezier curves

I am currently working on a curve implementation for use in Unity which includes an editor: The aim is to get an object to follow the path represented by the curve at a constant velocity. Currently ...
3
votes
2answers
1k 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 ...
2
votes
2answers
496 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
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
848 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
2answers
2k 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
2answers
116 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
2answers
3k views

Line Intersection from parametric equation

I'm sure this question has been asked before. However, I'm trying to connect the dots by translating an equation on paper into an actual function. I thought It would be interesting to ask here instead ...
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
votes
4answers
4k 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
3answers
955 views

How do I interpret the dot product of non-normalized vectors?

I know that if you take the dot-product of two normalized vectors, you get the cosine of the angle between them. But if I take the dot-product of two non-normalized vectors (or one normalized, one ...
2
votes
1answer
653 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
3answers
103 views

Unity - Check if object is facing Vector3 coordinates

I am having a hard time figuring this out, I want to have objects that move around randomly, and when they get new coordinates to move towards, face them, and then move. Here's explained: Target ...
2
votes
2answers
1k 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 ...
2
votes
3answers
2k 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
2k 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
294 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
447 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
1answer
64 views

How do I create a rocket projectile that is “dropped”, then accelerates toward the enemy?

I'm making an Asteroids-like game. I've successfully implemented linear bullets. Now I want to add some rocket-styled bullets, with a certain flight path: The rockets should be "dropped" back first, ...
2
votes
2answers
883 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
2answers
981 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
1k 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
109 views

Unity 3D - Rotate towards object with random offsets

Title is a little confusing, but let me explain: I want to make the enemies look at the player, and shoot at him, with random precision, meaning that one time the enemy will shoot a little bit to the ...
2
votes
2answers
647 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 ...