Arithmetic, geometry, calculus, and all else which resolves the number-crunching necessary in a game. Math questions are those that deal with the formulae and calculations used by the game in various parts.
1
vote
1answer
149 views
Anybody remember this webpage? [closed]
I remember visiting a webpage some time ago (1 year ago maybe)
It contained many java applets, describing how certain mathematical functions like sin, cos, arcsin, exp would make an object move, with ...
3
votes
2answers
2k views
Basics of drawing in 2d with OpenGL 3 shaders
I am new to OpenGL 3 and graphics programming, and want to create some basic 2d graphics. I have the following scenario of how I might go about drawing a basic (but general) 2d rectangle. I'm not ...
0
votes
2answers
1k views
As3 Random movieclips from an array to the stage
For a game with orders and clients I was trying to create the following situation:
Every half minute, a client should appear at the counter. In this case I have an array with 4 movieclips (4 ...
3
votes
2answers
432 views
Trying to understand 2D vector -> projection space conversion
I'm trying to understand how I can transform 2D vectors (x, y) to projection space. Something hasn't quite clicked for me yet. As per my previous question, here's the effect I'm trying to achieve:
...
1
vote
1answer
218 views
Isometric Optimization in javascript
I'm having some issues with my optimization of my game.
I have a simple tile map looped like this in my case the images are 64 by 64 pixels:
for (i=0; i < 50; i++){ //horizontal
for (j=0; ...
4
votes
2answers
2k views
How to calculate shot angle and velocity to hit a moving target?
I am developing a 2D Android game and I am making an aiming algorithm for AI projectiles to hit enemies either following a path, or free moving. At the moment it just calculates where the target will ...
4
votes
2answers
856 views
Matrix for 2D perspective
I'm trying to determine whether what I'm attempting to achieve is even possible mathematically. I'm obviously not a seasoned game developer so I'm having trouble even coming up with the terminology to ...
2
votes
3answers
745 views
need to create formulas for stat, level progression etc. What tools will help the not-mathematically-literate?
I want to create some of the fundamental guideline formulas for a game I am working on. I am following on from sirlin's advice in that I am starting with some assumptions and working back from there.
...
5
votes
3answers
616 views
Arbitrary projection matrix from 6 arbitrary frustum planes
A projection matrix represent a tranformation from the camera view space to the rendering system clip space. In other words, it defines the transormation between a 6-sided frustum to the clip cube.
...
4
votes
2answers
264 views
How to draw equal length line stripes on a parabola?
Simply put I'm making a basketball game. I'm using these equations to predict the ball position and it works fine:
x = vx * t
y = vy * t + 0.5 * gravity * t * t
But I can't find a way to draw equal ...
2
votes
3answers
1k views
How do I shoot bullets towards the mouse in a top down shooter?
I have a formula for pointing my main character of the game towards the mouse, and it gets the angle he needs to be turned to point towards the mouse. But how do I get the bullets from the gun to use ...
1
vote
2answers
276 views
How to keep the questions in Math game application ?
I would like to create a simple Math game application in android phone but I don't know what kind of data storage which I should use to keep the sets of numeric for the questions.
At this time, I am ...
5
votes
2answers
280 views
How to generate random points on the surface of a quadrilateral
Alright, I'm sure there has to be a simple way to do this but it eludes me at the moment.
I want to be able to generate random points on the surface of a quadrilateral in 3D space. (Defined simply as ...
2
votes
1answer
282 views
High school-level geometry book focusing on game dev for struggling student?
Here's the situation. My brother, a freshman in high school, isn't doing too well in geometry. Partially because he doesn't do half the work, but partially because he seems to have genuine ...
1
vote
1answer
452 views
Relating a point after an image is panned and zoomed
For Android, let's say you have a image of a map that you draw inside your view. On this map there are many, many "hot spot" locations where you want your user to be able to select. Given that there ...
5
votes
2answers
132 views
Drawing a line from a random coordinate through a given point
When the mouse button is clicked, I want to draw a line from (0, random) to (640, y) which goes through the click position.
How would I calculate the y coordinate of the end of the line?
20
votes
4answers
1k views
Are there any disadvantages of using Distance Squared checks rather than Distance?
I use distance squared checks for basically all my distance (vector3 length) checking, due to the performance increase from not incurring a square root (like in plain length checks).
From the looks ...
4
votes
3answers
1k views
Determine Resulting Angle of Wall Collision
So I have an object moving in a direction towards a fixed horizontal or vertical wall. How do I compute the angle that the object should bounce off at? The object can approach the wall at an arbitrary ...
10
votes
2answers
920 views
Why do people use quaternions?
I have been using them as a black box for a while, I'm just learning about of the maths but I'd just like some definitive answers to this question.
So far the only benefit I've come across personally ...
2
votes
2answers
539 views
How to interpolate a height-map with normals
My Task
I want to interpolate a heightmap by using the normal of each nearby point of the heightmap which is calculated before. When having 4 Points before i gonna have 9 points after it. ( See this ...
2
votes
3answers
761 views
simplest way of making a sphere roll in a realistic way
rather than just moving a sphere across a plane, I want to make it roll like a ball. What is the simplest way of doing this? I assume it will have something to do with the circumference of the ball ...
4
votes
2answers
302 views
Box-box contact information
I have two colliding boxes, How i can calculate contact information like (contact normal, contact point and penetration) .
Is there any simple algorithm .
Note: i'm using XNA .
2
votes
1answer
315 views
Confused about order of operation when using a Matrix in XNA, C#
Here are two different pieces of code
This is what I started with
Vector2 hold = Vector2.Transform(pos1, mat1);
Matrix inv = Matrix.Invert(mat2);
Vector2 pos2 = Vector2.Transform(hold, inv);
And ...
1
vote
1answer
414 views
Problems with 3D rotation when creating a 3D skeleton
I am writing a simple BVH parser in C# using the XNA framework. At the moment I have managed to parse in all the data and my goal is to find out the global coordinates of all the joints in the ...
2
votes
1answer
324 views
How to linearly transform vertices for large coordinate systems
Alright, so I'm working on a space game and well, I want it to have a lot of space! So I need a large coordinate system and for my rendering pipeline to not suffer from "vertex jittering" due to ...
5
votes
3answers
649 views
What's a pre-multiplied 4x4 matrix?
I'm using a 3d game engine, that uses a 4x4 matrix to modify the camera projection.
The matrix is in the regular 4x4 format:
r r r x
r r r y
r r r z
- - - zoom
The description for the ...
4
votes
1answer
471 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, ...
2
votes
1answer
264 views
Formula to calculate the changes in the fortunes of a stock based on how many shares are bought or sold
I am creating a stock market simulator for an event in my college. Supposing I have 20 companies in it all starting with a common base price, I need a formula to calculate the changes in the fortunes ...
3
votes
3answers
3k views
How to get translation from view matrix
How can I retrieve the camera's world-space position from its view matrix?
The only answers I've seen to this question suggest the translation is in the last row/col but this wouldn't work since the ...
7
votes
1answer
571 views
Helicopter game, but waves?
I'm looking into adapting the classic "helicopter" game (i.e. http://www.addictinggames.com/helicopter.html), but I haven't yet figured out how to create the wall-generation engine.
Any pointers into ...
3
votes
1answer
1k views
Understanding log/exp formula for RPG experience
While looking for examples of RPG experience formulas I came across this one
How to create adjustable formula for RPG level up requirements?, and I would really like to figure it out because I don't ...
15
votes
2answers
487 views
How can I evenly fan out a hand of cards?
Given a set of playing cards (rectangle images with a width and height) how can I rotate and position each one so that they appear in a 'fan' pattern, much like you would hold a hand of cards in real ...
2
votes
3answers
997 views
Suggest a simple Java math library for matrix operations for use with OpenGL (lwjgl) [closed]
I'm writing an OpenGL app with Java. I need to do some math for camera and frustum culling (for AABB). Could you suggest a simple and fast Java math library for that?
2
votes
4answers
1k 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 ...
1
vote
2answers
286 views
Should SIMD be used by people who are new to game development?
I have been learning game development, using C++ and OpenGL, for about 4-5 months. Before that I used to program in C# and the .NET platform(about a year). So, I consider myself new to game ...
8
votes
2answers
562 views
Function for sun movement?
So, given a sun sprite set at the horizon (x = 0, y = worldheight/2) I'm trying to devise a function to make the sun rise, then fall.
The best way to do this would be the sin function, but I have no ...
10
votes
5answers
1k views
Quick 2D sight area calculation algorithm?
I have a matrix of tiles, on some of that tiles there are objects. I want to calculate which tiles are visible to player, and which are not, and I need to do it quite efficiently (so it would compute ...
2
votes
2answers
676 views
Dot Product Vs Cross Product Turning a Turret Towards A Enemy and firing
http://pastebin.com/iw9DHf7s is code demonstrating dot product turning a turretto a target and firing. It works and chooses best angle to spin.
A problem can occur when game goes faster (better ...
3
votes
1answer
846 views
Opengl-es picking object
I saw a lot of picking code opengl-es, but nothing worked. Can someone give me what am I missing?
My code is (from tutorials/forums)
Vec3 far = Camera.getPosition();
Vec3 near = ...
4
votes
4answers
276 views
What should be taken into consideration when choosing a math library for games?
I'm currently selecting a C++ math library to use for a project. There are several questions here and on SO concerning the 'best' library available and many answers with different suggestions, but I ...
-1
votes
1answer
148 views
How to implement cue-stick animation for a pool game?
Hello I am developing a Pool game, and I've been scratching my head about what formula is needed to implement an animation for the cue stick.
The animation of the cue stick should look as if it's ...
0
votes
2answers
420 views
Moving along a flat plane with accordance to camera view
I'm making a 3D game, and I'm stuck on a little experiment.
I currently have a flat plane with a free camera running around, and a sphere (really, a light approximated as a sphere) that rests above ...
6
votes
2answers
165 views
How do you calculate if a line is facing a curve?
Given the 2 points describing a line segment, and the 3 points describing a quadratic bezier curve, how do you calculate if the line is facing towards or away from the curve?
The line has a fixed ...
3
votes
1answer
255 views
How do you triangulate a 3D point from a pair of stereo images?
I'm working with a stereo pair of photos, and trying to obtain a set of 3D points from matching points on these 2 images. How exactly is the point triangulated? Do you throw a ray from the camera ...
8
votes
7answers
549 views
How to create a mathematical mechanism in order for a game to be balanced?
For example, in a game like Diablo, how did they decide how much damage each skill does?
Is it the amount of clicks that the player needs to do? Or maybe the expected lifetime of a player? Maybe ...
5
votes
1answer
257 views
What is the point of this hard-coded vector when calculating luminance in glow/bloom effects?
I have looked at two different vertex shaders that calculate luminance and both use a "magic" vector that I'm not sure the meaning of the the actual values. For instance:
const mediump vec3 ...
0
votes
1answer
89 views
Finding the angle of a line given 2 other lines
I'm trying to implement some 2D vehicle physics. For this to work I have 2 wheels attached to the body of the car. After doing some collisions checks I place the wheels at their new position. Say the ...
2
votes
4answers
1k views
What is an efficient 2D line-segment-versus-triangle intersection test?
In a 2D plane, I have a line segment (P0 and P1) and a triangle, defined by three points (t0, t1 and t2).
My goal is to test, as efficiently as possible ( in terms of computational time), whether the ...
13
votes
3answers
318 views
How do you calculate the nearest point on 2 curves?
Given the points of a line and a quadratic bezier curve, how do you calculate their nearest point? .... Similarly, given the points of 2 curves, how do you get the nearest point?
8
votes
2answers
284 views
How do you calculate if 2 lines are facing toward or away?
Given the 4 points describing 2 line segments, how do you calculate if line A is towards or away from line B?
The 2 lines have a fixed length, and can be measured as distance from x1/y1 to x2/y2.
