A mathematical concept that can be used to express position, direction or velocity and which can simplify or outright trivialise spatial problems.
4
votes
2answers
97 views
Normal, tangent and binormal vectors
I would like to find out the following information:
What it is?
Example usage in game development (the area it is used in)
about the following vector types:
Normal
Tangent
Binormal
A simple ...
0
votes
0answers
28 views
Uses for vector projection?
My previous question was solved by vector projection. Thus I spent some time studying it (Few helpful links: Interactive projection, short video and a longer video.).
There were plenty of sites that ...
1
vote
0answers
32 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 ...
3
votes
3answers
128 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
0answers
39 views
Rotating plane to be parallel to given normal via change of basis
I have two planes and their respective normals. I would like to rotate the second plane, planeB, so that it is parallel to the first, planeA.
To do this, I am using a change of basis to rotate each ...
2
votes
2answers
209 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, ...
0
votes
1answer
59 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 ...
0
votes
1answer
78 views
Character movement relative to cursor position
I want my top-down shooter character to move towards the mouse when pressing the up arrow and strafe relative at right angles to it when pressing the left and right arrow keys.
I can't figure out how ...
1
vote
1answer
81 views
Movement constrained to the faces of a cube
The basic setup I'm working with is a cube rendered in-Engine (Panda3d, although I only am looking for a generalized solution) as well as a 2d square on one face of the cube. The eventual outcome I'm ...
0
votes
0answers
35 views
Working out total amount of dice in c++ Liar's Dice [migrated]
I have an issue with my Liar's Dice game I'm doing for as assignment in C++
Currently, I have the player's hand working fine (5 dice) and the opponent's hand working fine (also 5 dice). I also have ...
2
votes
1answer
151 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 ...
7
votes
7answers
477 views
What's the best way of translating a 2D vector into the closest 8-way compass direction?
If you have a 2D vector expressed as x and y, what's a good way of translating that into the closest compass direction?
e.g.
x:+1, y:+1 => NE
x:0, y:+3 => N
x:+10, y:-2 => E // closest ...
0
votes
3answers
196 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 ...
2
votes
3answers
199 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 ...
0
votes
4answers
128 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 ...
8
votes
3answers
434 views
Vector3 vs. Vector2 - performance, usage?
I'm currently playing around with XNA, and creating a simple 2D platformer. I was thinking of adding multiple layers to make it a little bit of challenge.
In stead of having a Vector2 for my ...
0
votes
1answer
98 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 ...
1
vote
1answer
65 views
Confusing with an articles wording on Clamping a Vector2
I have been reading an article on Collision Detection and how to resolve it.
http://www.wildbunny.co.uk/blog/2011/04/20/collision-detection-for-dummies/
In the section describing an AABB vs Circle, ...
-4
votes
2answers
147 views
enemy shooting towards FPS [closed]
WELL first of all I want you to see my game (its deployed on heroku cloud) :
http://still-escarpment-3701.herokuapp.com
(It takes almost 10 sec to load so please wait for couple of sec)
I have ...
2
votes
1answer
136 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 ...
0
votes
0answers
37 views
Transform a Screen Delta
I have a delta in screen coordinates that I want to transform to a 3d delta in world space.
The delta is in this case a movement across the (x,y) coordinates in screen space on the near projection ...
1
vote
1answer
228 views
Understanding math used to determine if vector is clockwise / counterclockwise from your vector
I'm reading Programming Game AI by Example by Mat Buckland. In the Math & Physics primer chapter there's a listing of the declaration of a class used to represent 2D vectors.
This class contains ...
-1
votes
3answers
192 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, ...
1
vote
2answers
160 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 ...
3
votes
1answer
229 views
Raycasting tutorial / vector math question
I'm checking out this nice raycasting tutorial at http://lodev.org/cgtutor/raycasting.html and have a probably very simple math question.
In the DDA algorithm I'm having trouble understanding the ...
2
votes
3answers
295 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 = ...
1
vote
2answers
275 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 ...
0
votes
1answer
73 views
Using NumPy arrays as 2D mathematical vectors?
Right now I'm using lists as position, velocity, and acceleration vectors in my game. Is that a better option than using NumPy's arrays (not the standard library's) as vectors (with float data ...
15
votes
7answers
502 views
Do I need a Point and a Vector object? Or just using a Vector object to represent a Point is ok?
Structuring the components of an engine that I am developing along with a friend (learning purposes), I came to this doubt.
Initially we had a Point constructor, like the following:
var Point = ...
1
vote
2answers
102 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 ...
0
votes
1answer
99 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 ...
1
vote
1answer
125 views
How do I get the axes for SAT collision detection
In SAT collision detection how do I calculate the axes for projection?
2
votes
1answer
147 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 ...
3
votes
2answers
115 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 ...
0
votes
1answer
89 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 ...
2
votes
1answer
133 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 ...
1
vote
1answer
160 views
How to get a point to the left/right of a vector
I have a position vector of a point in space and a quaternion for it's rotation. What i'm trying to calculate is a point too the left and a point to the right.
I have the position and ...
3
votes
2answers
238 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 ...
4
votes
1answer
774 views
How do I rotate a sprite so that it is 'pointing' in the direction it is moving
I have a sprite, e.g a missile, heading in a certain direction (using a velocity vector).
How do I figure out its how much to rotate it so that it gets drawn 'pointing' in the direction it is ...
1
vote
1answer
274 views
how can i get rotation vector from matrix4x4 in xna?
i want to get rotation vector from matrix to realize some parent-children system for models.
Matrix bonePos = link.Bone.Transform * World;
Matrix m = Matrix.CreateTranslation(link.Offset)
* ...
3
votes
3answers
125 views
Determining a point that reached another point
I have two points, one is moving and one is stationary. I would like to know if the moving point has reached that point or not. I tried to calculate the distance between two vectors and the distance ...
3
votes
1answer
93 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 ...
1
vote
2answers
135 views
Billboarding + aligning with velocity direction
I'm working on a particle system where I'm orientating the billboard using the inverted orientation matrix of my camera. This works quite well and my quad are rotated correctly towards the camera.
...
6
votes
2answers
346 views
Rotate a vector
I want my first-person camera to smoothly change its viewing direction from direction d1 to direction d2. The latter direction is indicated by a target position t2.
So far I have implemented a ...
0
votes
0answers
214 views
C++ Directx 11 D3DXVECTOR3 doesn't allow me to devide it [closed]
If i have a simple vector3 like this:
D3DXVECTOR3 inversevector = D3DXVECTOR3( (pos+lookat_pos));
It works perfect!
But let's say i wanted to multiply it by:
Speed*(float) timeHandler.GetDelta()
...
5
votes
1answer
188 views
Moving in a diamond - enemy gets stuck
I have an enemy that I would like to move as follows:
Start at (0, 200, 0)
Move to (200, 0, 0)
Move to (0, -200, 0)
Move to (-200, 0, 0)
Move to start point, repeat as long as it remains active.
...
-1
votes
4answers
129 views
What is a good starting project to get up to speed with vectors and vector math? [closed]
I have been getting into games programming recently. However, all I have made so far (in order) is Snake, Breakout and Tetris.
I want to take on a bigger project, and some research has led me to ...
3
votes
1answer
188 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 ...
1
vote
1answer
374 views
Rotate triangle so that its tip points in the direction of the point on the screen that we last touched
OpenGL ES - Android.
Hello all, I am unable to rotate the triangle accordingly in such a way that its tip always points to my finger.
What i did : Constructed a triangle in by GL.GL_TRIANGLES. Added ...
1
vote
1answer
367 views
Unity: parallel vectors and cross product, how to compare vectors
I read this post explaining a method to understand if the angle between 2 given vectors and the normal to the plane described by them, is clockwise or anticlockwise:
public static AngleDir ...
