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.
9
votes
1answer
953 views
Adding air drag to a golf ball trajectory equation
I'm developing a 2D golf game in VB.NET 2005, but I am stuck on how to implement air or wind drag that should affect the ball.
Already I have these equations for projectile:
Vo ...
9
votes
3answers
1k views
How to calculate the rotation resulting from ball bounce
Hey all, still working to incorporate more physics simulation into my game (mentioned HERE). Now having the ball successfully and quite realistically bouncing a surface it hits, I wanted to make the ...
9
votes
1answer
387 views
Algorithm to shoot at a target in a 3d game
For those of you remembering Descent Freespace it had a nice feature to help you aim at the enemy when shooting non-homing missiles or lasers: it showed a crosshair in front of the ship you chased ...
9
votes
1answer
250 views
Deforming surfaces
I try to accomplish an deforming physic behaviour for levelsurfaces, but don't get an idea how to start with the implemenation so far.
Regardless of the shape from the surface (planes, cubes, ...
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 ...
8
votes
6answers
1k views
Weighted Random Distribution
I am currently contributing to a particle system for our game and developing some emitter shapes.
My uniform random distribution along a line or along a rectangular area works fine - no problem.
But ...
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votes
3answers
1k views
How to move an object along a circumference of another object?
I am so out of math that it hurts, but for some of you this should be a piece of cake.
I want to move an object around another along its ages or circumference on a simple circular path. At the moment ...
8
votes
2answers
563 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 ...
8
votes
4answers
1k views
Staggered Isometric Map: Calculate map coordinates for point on screen
I know there are already a lot of resources about this, but I haven't found one that matches my coordinate system and I'm having massive trouble adjusting any of those solutions to my needs.
What I ...
8
votes
2answers
247 views
100 points between 0-1000 on an increasing scale
Basically, it's for roleplay, I need to generate 100 points along a scale. Level 1 is the starting amount, and is at point 0 on the scale. Level 100 is the highest amount planned at this point, and it ...
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.
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votes
2answers
3k views
How do I linearly interpolate between two vectors?
I have a velocity vector where my client is at and where its going, and I have the same vector that comes from the server telling where the client should be. Sometimes its a bit different, so I want ...
8
votes
2answers
2k views
Float, double or both for 2D Vector class?
I'm currently writing a small cross-platform OpenGL-based 2D game engine for our studio. When I researched which 2D Vector class to use, I stumbled across three different design paradigms:
Float ...
8
votes
3answers
377 views
How does one separate the acceleration due to gravity from other motion in accelerometer input?
How does one separate the acceleration due to gravity from other motion in accelerometer input?
8
votes
2answers
290 views
Render 3d object to 2d surface (embedded system)
i am working on an embedded system of a sort, and in some free time i would like to test its drawing capabilities.
System in question is ARM Cortex M3 microcontroller attached to EasyMX Stellaris ...
8
votes
5answers
415 views
Building (simple) stellar systems
I'm currently looking at how to easily simulate some stellar systems (meaning some central stars and then some planets with maybe satellites), in order to allow later some space based strategy game ...
8
votes
2answers
295 views
Drone targeting
Imagine a "drone" and a target point on a 2d plane. There are eight parameters:
P = my position
Q = target position
V = my velocity
I = my moment of inertia
w = my angular velocity
s = my angular ...
8
votes
6answers
379 views
Is there a (family of) monotonically non-decreasing noise function(s)?
I'd like a function to animate an object moving from point A to point B over time, such that it reaches B at some fixed time, but its position at any time is randomly perturbed in a continuous ...
8
votes
3answers
685 views
What are the most common splines you will find in game development?
List here the most common splines found in game development, how many points the method needs to interpolate a curve, and how can you build a data type that allows you to get an interpolation of the ...
7
votes
5answers
524 views
Circular Bullet Spread not Even
I'm creating a bullet shooter much in the style of Touhou. Right now I want to have a very simple circular shot being fired from the enemy.
See this picture:
As you can see, the spacing is very ...
7
votes
4answers
647 views
Not sure how to handle “deceleration”
I say "deceleration" because I'm not using acceleration at the moment (it is being calculated, it's just set to 0 0); what I mean is moving the velocity back towards zero, eventually stopping.
I'm ...
7
votes
1answer
2k views
Circle-Line Collision Detection Problem
I am currently developing a breakout clone and I have hit a roadblock in getting collision detection between a ball (circle) and a brick (convex polygon) working correctly. I am using a Circle-Line ...
7
votes
1answer
268 views
How do I find a point on a line?
I have two points (A, B) and the length of d. How can I find point C?
7
votes
1answer
343 views
Projected trajectory of a vehicle?
In the game I am developing, I have to calculate if my vehicle (1) which in the example is travelling north with a speed V, can reach its target (2). The example depict the problem from atop:
There ...
7
votes
5answers
3k views
SIMD C++ library
I've use Visual Studio with the DirectX XNA math library. Now, I use the GNU compiler collection. Can anyone advise a SIMD math library with a good documentation?
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votes
2answers
1k views
Is there a simple way to do true isometric projection with an HTML5 canvas?
Is there a simple way to get a true isometric projection with the HTML5 canvas element?
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votes
3answers
4k views
Sorting array of points in clockwise order
Is there such an algorithm to sort an array of 2D points in clockwise order?
I'm specifically dealing with right triangle in my case so only 3 points.
However I'm interested in knowing if such an ...
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 ...
7
votes
3answers
712 views
Calculating Experience Points earned after a battle
I'm developing a simple text battle game and having some issues calculating how much XP should be earned after a battle, theres a few factors that i want to consider:
1) Players should of course earn ...
7
votes
3answers
4k views
What is a simple algorithm for calculating evenly distributed points on an ellipse?
I am looking for a simple algorithm to plot evenly distributed points on an ellipse, given the major and minor axes. This is really easy to do with a circle like so:
var numberOfPoints = 8;
var ...
7
votes
3answers
1k views
How to smoothly let an object move along a curved line
I'm wondering how to move objects, with rotation taken into account, to follow a curved line
see: http://www.youtube.com/watch?v=iPpO24FeAX4 for an example
In particular I wonder:
how to store the ...
7
votes
2answers
545 views
Calculation of Inertia Tensors
Bit of a complex and lengthy question that, I'll admit, I don't quite understand very well yet so I will try and explain as best as I can.
Short Version: Is there a general c++/physx formula out ...
7
votes
3answers
1k views
Rotating a vector by another vector in shader
I have a terrain surface with a normal for each point on the terrain.
I have a second detail normal map to be applied to the terrain.
These normals are in 3-space.
The Y value of both normals is
...
6
votes
6answers
2k views
Does a minor in math increase my hirability?
Hey there! I've been pondering this question for some months now, and have been unable to get an answer from anyone in the industry (likely because I know no one in the industry).
I am currently ...
6
votes
4answers
2k views
How can I render a circular progress bar procedurally?
I'm working in Flash AS3, but pseudo-code or any other language is fine.
How can I make a circular progress bar? Akin to the ship bars in Pax Britanica, you can see them in the screenshot here.
...
6
votes
3answers
456 views
Abstracting multiple math libraries with C++
I would like to create some level of abstraction above math in my code. I mean I don't want to be dependant on the implementation of math operations or even on class names, which are provided by some ...
6
votes
1answer
3k views
Get position of point on circumference of circle, given an angle?
I would like to know how to get a specific point on the circumference of a circle, given an angle. The diameter of the circle is 1, and the center point of the circle is { X: 0.5, Y: 0.5 }.
6
votes
4answers
838 views
Equation for bouncing graph?
I basically want my camera in 3D move automatically. Currently, I have linear movement which is rather dumb, so I'd like to do a bouncing movement.
However, what is a good equation for bouncing? I ...
6
votes
2answers
182 views
make a sphere rolling on a roulette mesh stop at predetermined place
I have a roulette and a ball(sphere) placed on it. When the game begins the roulette spins. The spinning of the roulette and gravitational forces on the ball makes it roll along the 3d roulette mesh.
...
6
votes
5answers
912 views
Can someone explain the (reasons for the) implications of colum vs row major in multiplication/concatenation?
I am trying to learn how to construct view and projection matrices, and keep reaching difficulties in my implementation owing to my confusion about the two standards for matrices.
I know how to ...
6
votes
4answers
2k views
Calculating velocity needed to hit target in parabolic arc
If I have a point which I want to hit at the end or during a parabolic arc, how would I calculate the needed x and y velocity?
6
votes
2answers
359 views
What score/level function is often used?
In many games you raise a level when you reach a certain score, and later levels are harder to reach than in the beginning.
I am suspecting that it is some sort of exponential function that is used ...
6
votes
3answers
744 views
Find a unit vector exactly halfway between two connected line segments
Seems like a quick and easy question but I haven't been able to find exactly what I'm looking for so:
How to calculate a unit length vector that is pointing along the line which is exactly 50% of the ...
6
votes
2answers
250 views
Self-righting agents that have fallen over
I need insect-like agents that have fallen/rolled on their back/side to naturally re-orient themselves. The agents are modeled as simple cuboids in the physics engine (Bullet) to approximate an ...
6
votes
2answers
1k views
How to calculate the exit speed of ball bouncing off a solid surface
Hey all, I am working on a simple game to include some rigid body dynamics, involving placing (moving & rotating) some springs to bounce a falling ball into a target area.
My problem is correctly ...
6
votes
1answer
190 views
Matrices: Arrays or separate member variables?
I'm teaching myself 3D maths and in the process building my own rudimentary engine (of sorts). I was wondering what would be the best way to structure my matrix class. There are a few options:
...
6
votes
1answer
215 views
How can I get a 2D texture to rotate like a compass in XNA?
I'm working on a small maze puzzle game and I'm trying to add a compass to make it somewhat easier for the player to find their way around the maze. The problem is: I'm using XNA's draw method to ...
6
votes
1answer
1k views
Moving a particle around an Archimedean spiral at a constant speed
I want to move a particle in a spiral at a constant speed. Note that that is not a constant angular speed. This is proving rather difficult, and I'll go through my method so far below.
The spiral in ...
6
votes
3answers
984 views
How can I get a velocity vector for an object moving in a circle?
I am simply trying to make an object move in a circle around a point. Let's say I have an object with a position vector going from that point to the object, and also the angle of the object with the x ...
6
votes
2answers
231 views
Elliptical orbit modeling
I'm playing with orbits in a simple 2-d game where a ship flies around in space and is attracted to massive things. The ship's velocity is stored in a vector and acceleration is applied to it every ...
