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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0
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2answers
112 views

Collision detection: Swinging bat/racket and ball

I am programming a side-view tennis game, inspired by an old arcade game, using Javscript and HTML5 canvas elements. The player can move left and right and holds a racket at arms length which can be ...
0
votes
1answer
75 views

Loading non-square textures, from a 256x256 spritesheet in lwjgl(JAVA)

so I'm doing lwjgl, so far I have the loading of 16x16 textures from a 256x256 spritesheet all working, using this code to get the location of the textures: public Vector2f[] calculateUVMapping(int ...
0
votes
1answer
96 views

Rotating a vector around a vector in 3D space

I am trying to rotate a moon around a planet (the planet is also rotating around an axis) but I am having trouble doing so. I tried to make the model move through space like so: @Override public ...
1
vote
0answers
116 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, ...
0
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0answers
44 views

How to make a game like “pewpew”? [duplicate]

I have a question about the graphics of these games like "pewpew", "geometry wars". Pewpew. Visit here: https://play.google.com/store/apps/details?id=com.jyaif.pewpew&hl=en How these games are ...
3
votes
2answers
605 views

How to find point on a circle that's opposite another point?

How do I find the coordinate of point and angle value on circle sprite which placed on opposite side of sprite from a touch point and the center point of the sprite? I know A position, B position and ...
14
votes
5answers
5k views

Do I need the 'w' component in my Vector class?

Assume you're writing matrix code that handles rotation, translation etc for 3d space. Now the transformation matrices have to be 4x4 to fit the translation component in. However, you don't actually ...
0
votes
2answers
248 views

How to add a constant horizontal force just like gravity?

I want to add a constant horizontal force, just like gravity to a projectile or a sphere moving in 3d space, which will make the projectile or ball or sphere or whatever be influenced by this force so ...
0
votes
0answers
87 views

Closest distance from 3D point to vector line

First let's have a look at my little drawing: I have an origin point p1 defined by x, y and z co-ordinates, and a vector v given by x, y and z magnitude. I also have an arbitrary point, p2, given ...
6
votes
3answers
4k views

Implementing Separating Axis Theorem (SAT) and Minimum Translation Vector (MTV)

I was following codezealot's tutorial on SAT and MTV and trying to implement it myself but I've come a cropper when it comes to getting the correct MTV. Here is my example: (Cue pretty pictures...) ...
1
vote
2answers
75 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 ...
4
votes
2answers
1k views

What is a good way to determine if a vector is between two other vectors?

I could operate with the angles, but I do not have the angles calculated yet (and would like to avoid having to do that). It would be possible to calculate and cache the local-coordinate-frame angles, ...
1
vote
1answer
227 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 ...
1
vote
1answer
71 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 ...
0
votes
1answer
139 views

How do I find a unit vector of another in Java?

I'm writing a Java formula based on this tutorial: 2-D elastic collisions without Trigonometry. I am in the section "Elastic Collisions in 2 Dimensions". Part of step 1 says: Next, find the unit ...
0
votes
1answer
125 views

What is wrong with my specular phong shading

I'm sorry if this should be placed on stackoverflow instead however seeing as this is graphics related I was hoping you guys could help me: I'm attempting to write a phong shader and currently working ...
1
vote
1answer
87 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 ...
4
votes
2answers
1k views

Why isn't this physics code scaling velocities separately?

I'm working my way through this book and I'm trying to work this code out: var squaredVelocity = this.velocity.x*this.velocity.x + this.velocity.z*this.velocity.z; if ...
1
vote
1answer
132 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 ...
3
votes
3answers
4k views

Is there a good cross-platform C++ vector graphics library out there? [closed]

I'm making a game and want to use vector graphics. I started re-coding it using Cairo and the performance is horrific. So, I'm looking for a different library. It needs to be for C++ and ...
0
votes
0answers
135 views

How do I find the camera direction vector for 3D sound purposes? (C++, DirectX)

Question I'm trying to make a sound class for playing 3D sound effects with DirectSound and DirectX, without using DirectSound's 3D libraries. The plan is to have every game object constantly play ...
0
votes
1answer
122 views

Projecting a light onto a quad

I need to project the light onto the quad and use its value for translating the vertices. I'm currently having 6 vertices, two quads, The points are A X C B Y D Point X, Y are coming from two ...
1
vote
1answer
167 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 ...
9
votes
2answers
389 views

Dynamic thruster balancing of space ship

The space ships in my game a meant to be player-built with an arbitrary amount of thrusters attached anywhere with any rotation. I currently have some dirty code to rotate the ship to a given angle ...
0
votes
1answer
49 views

How to set LinearVelocity exactly in onSceneTouchEvent?

I'm beginner in Android programming. And i use AndEngine GLS2 with Body and AnimatedSprite. I have a object ball and i want to move it to follow my hand. This is description for my idea: And my ...
1
vote
1answer
53 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 ...
0
votes
1answer
66 views

How to tell right from left: Finding the vector pointing towards the right side of a character?

We have two vectors: Pointing from the floor to a 3d character's head. Pointing from the character towards where it's facing. How do I find the vector point from the character towards the right? ...
0
votes
0answers
39 views

How to find optimal perpendicular axis of rotation vector to draw arrows?

I am drawing lines on the screen. Each line has a point (x,y,z) and a direction (u,v,w). I want to draw arrow heads on these lines, like two lines that start from (x,y,z) and leave at a 15 degree ...
0
votes
0answers
120 views

How to rotate a line in 3d space?

I am trying to figure out direction vectors of the arrowheads of an arrow. Basically I'm given a normalized direction vector (u,v,w) and I need the normalized direction vectors of the its two arrow ...
0
votes
1answer
118 views

Relative Position/Rotation calculation

I have 2 objects each with a 3x3 Matrix (Orientation) and a Vector3 (Translation). Both are relative to world coordinates. How do I calculate the position and orientation of object B in relation to ...
1
vote
1answer
388 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 ...
0
votes
1answer
166 views

Separating axis Theorem rotation issue

I made a post yesterday to see if anyone could understand my problem. However I did not receive much guidance, probably because my question was not clear. I have worked on it a little more and ...
-2
votes
1answer
102 views

How to remove line between two Points XNA 4.0?

I'm new to XNA and wondering if it is possible to remove a line (that lies between two vectors) when the mouse clicks on that line. I've searched everywhere but I can't seem to find anything. My ...
2
votes
1answer
274 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?
1
vote
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, ...
0
votes
0answers
53 views

How to move objects flat on different planes in 3d?

I need to move objects in circular/square/sinusoidal patterns in a flat manner on a collection of different and rotating planes in 3d space. I have the perpendicular of the planes. One method is to ...
0
votes
2answers
243 views

Using a vector to store multiple instances of a class

To warm up with SMFL, I am creating a simple Block Breaker game. For the blocks and balls, I would like to store them as "instances" in a vector so that they can be added/removed with ease. However, ...
0
votes
3answers
99 views

How can I calculate force and acceleration?

I have problem of calculating the movement of the object. At the moment, I have a vectors calculated from the center of the screen minus the position of the object. direction vector = centerScreen ...
1
vote
1answer
456 views

Ball bouncing at a certain angle and efficiency computations [closed]

I would like to make a pong game with a small twist (for now). Every time the ball bounces off one of the paddles i want it to be under a certain angle (between a min and a max). I simply can't ...
2
votes
2answers
32 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 ...
0
votes
1answer
51 views

Getting the position of a directional light w.r.t. a moving object.

I have a forward vector of my object, which is a bike, and its position, and I have a directional light direction. I would like to know where the light is with regards to the bike ...
1
vote
2answers
243 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 ...
0
votes
1answer
86 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 ...
1
vote
1answer
614 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
2answers
205 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 ...
1
vote
2answers
165 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 ...
0
votes
1answer
109 views

Tangent plane vectors smoothing with vertex normals [closed]

I'm trying to find a way to smooth out normals obtained from cross product of tangent and bitangent vectors calculated per face basis. I've already asked a similar question on SO, however with no ...
-2
votes
1answer
215 views

How to know the relative facing angles between two players? [closed]

I want a grappling system similar to Tekken, in which different grapples animations are performed depending on which side of the opponent the player performing the grapple is facing. For example, ...
2
votes
1answer
68 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 ...
10
votes
2answers
635 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 ...