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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1answer
135 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
242 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
104 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 ...
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1answer
453 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 ...
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0answers
301 views

Calculate initial velocity of a 3d vector-based projectile

Okay, so I got a Projectile with 2 Vectors, position and velocity. I now want to calculate the initial velocity for it in order to reach a specific point on the map. Or actually, how high has the ...
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2answers
336 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 ...
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1answer
3k views

The normal vector to a plane ax+by+cz+d=0?

I am calculating the normal vector to a plane ax+by+cz+d=0 According to the book: The normal vector N is often normalized to unit length because in that case the equation d = N ⋅Q + D gives the ...
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3answers
2k views

Scale a normalized 2D vector always to the same length

For any normalized 2D vector, except for ( 0, 0 ), how would I scale the vector to always be the same length? For example: int length = 10; vector v = vector( 0.1, 0.5 ); vector v2 = vector( 0.3, ...
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2answers
387 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 = ...
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2answers
161 views

How do I make a vector exactly reach a line?

Let's say a vector starts at Point P and points in the direction of v. How do I make sure that this vector exactly reaches the line? Its end should be exactly on the line, and not cross it.
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1answer
442 views

Vector reflect problem

I'm testing some vector reflection and I want to check what happens when a ball collides with a paddle. So if I have: Vector2 velocity = new Vector2(-5, 2); position_ball += velocity; if ...
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1answer
827 views

Determining and culling non-visible vertices

Ahoy! After posting my previous question on tile maps, i've been tinkering with an implementation i'm rather pleased with so far but would like to gather some more information about submitting ...
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3answers
86 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 ...
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2answers
362 views

Asteroids Movement

I have been making an asteroids clone, in C#. However, the ship's movement is... not quite right. My plan is this: there is a speed, and two directions, namely the direction the ship is facing ...
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3answers
1k views

Lerp vs Vector math: one better than the other?

In Unity3D (all versions, I believe), there is a static function for the Vector3D class called "lerp". It interpolates a point between two points a point, based off a provided percentage related to ...
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1answer
154 views

Vector2's static methods and the garbage collector

I discovered that Vector2's static methods return a different Vector2 from the parameters you give them and I'm under the impression that creating new objects and dereferencing old ones on this kind ...
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2answers
918 views

Calculating angle between two vectors to steer towards a target

I have been trying to implement a path following steering behaviour for AI in a 2D racing game. I have two vectors: futurePosition represents the predicted future position given the car's current ...
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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 ...
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2answers
705 views

Rotate point by a direction vector

Given a vector, A, which represents a point, and a unit vector, B, which represents the looking direction, how would I rotate A so that B is the axis that's looked down on? Let's say the looking-axis ...
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1answer
103 views

How do I find the angle between two 3D angles represented in this form?

I have two 3D angles, represented by [a1,a2] [a1,a2] where the a2 is < 180. My coordinates are represented as [X,Y,Z], where X,Y,Z are 64 bit ints (longs in my lang). My direction angles are ...
0
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1answer
108 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 ...
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2answers
167 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, ...
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1answer
535 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: ...
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1answer
65 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 ...
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votes
1answer
187 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 ...
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1answer
108 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 ...
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2answers
177 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 ...
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3answers
163 views

Keeping raycast on the same level

I want my raycast to end at certain height(red line). But as the game is 3D and the camera rotates I can't use a fixed magnitude. What I thought was a stroke of genius, I figured I'd project the ...
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votes
1answer
74 views

How to change Vectors due to change in it's dependent Base Vector?

PLOT : I have been developing a game where the player falls down on Y axis and the camera is a Top-Down view camera. The camera, player (main character in the game) movements etc. have all been ...
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1answer
101 views

How to Draw texture between 2 Vector3

My scenario: RTS combat style, 1 unit fires beam on another unit My problem is i want to draw a flat texture between 2 Vector3 points. I have looked at various Billboarding styles but that doesn't ...
0
votes
1answer
221 views

How can I draw a line rotated some number of degrees away from an original line?

I have a line ahead of my moving object to serve as a raycast and its aligned with the object's movement direction. But I want also some extra lines according to an angle related to the 'head' of the ...
0
votes
2answers
34 views

Converting A 3D Rotational Vector Into A 3D Forward Heading Vector

I need to do a raycast which accepts a Vector3D StartPos and a Vector3D EndPos. I have available to me the characters position and the cameras rotation in 3D vectors. I need to somehow compute a ...
0
votes
1answer
87 views

Simultaneously translating and rotating sprite in Unity

I have a 2D object (a PNG file I dragged onto the screen) which is a circle I would like to move left and right when the correct side of the screen is touched and have it rotate in the respective ...
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1answer
76 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 ...
0
votes
2answers
72 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
93 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 ...
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votes
1answer
42 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 ...
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votes
1answer
53 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? ...
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votes
1answer
150 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 ...
0
votes
1answer
88 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 ...
0
votes
1answer
102 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
81 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 ...
0
votes
1answer
221 views

Sharp DX Identity Matrix, Matrix.Forward vector pointing at negative Z

I'm trying to take a steady grip on Sharp DX. Already done some work like translating, scaling and rotating objects. Now i have to calculate the rotation matrix using only direction vector and ...
0
votes
4answers
211 views

How much to modify yaw? XNA 4.0 [duplicate]

Heres a picture that explains better than my words can For rotating an object I'm using quaternions. CreateFromAxisAngle(vector3.Right,yaw) Maybe this isn't how I should be doing it but I also ...
0
votes
1answer
386 views

Tilting towards turn direction (for a motorbike)

I have a motorbike which moves along based on a direction vector, I set its forward direction to the direction it's moving. What I'd like to also do with it is have the motorcycle tilt in the ...
0
votes
1answer
361 views

C++ and SDL Trouble Creating a STL Vector of a Game Object

I am trying to create a Space Invaders clone using C++ and SDL. The problem I am having is in trying to create Waves of Enemies. I am trying to model this by making my Waves a vector of 8 Enemy ...
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3answers
325 views

How would I successfully split a vector to increase game performance?

Okay so I have a vector for all of the monsters that are spawned in my game. All of these monsters are in a single vector and are "active" according to what zone they are in relative to the player's ...
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1answer
434 views

Calculate path of laser beam?

Lets say we have a laser beam emitter that has a position and an angle (in a 2D world to simplify things). The laser emitted from that emitter will start at that position, and continue heading in the ...
0
votes
1answer
52 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 ...
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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 ...