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
148 views
Is there a memory read/write or performance difference when applying affine transformations on a movieclip rather basic elementary math
I am using Actionscript 3.0 to make games and I fall into the category of programmers who use ball.x+=5;
ball.y+=5;
in order to move a ball by 5 pixels horizontally and vertically.
Well, now i seem ...
5
votes
2answers
962 views
top down game - checking, drawing enemy's line of sight area with obstacles
Examples of what i'm going to need:
I'm using cocos2d to draw a CCTMXTiledMap, on those tiles i'll have to draw the LOS cone.
How would i test if the player is within that cone, taking obstacles ...
3
votes
1answer
273 views
rotating an object from sourceAngle to destAngle, both 0-359, clockwise or counter clockwise?
I've got a game object i need to rotate. It's current angle is player.rotation, the destination is targetAngle, both in degress, 0 to 359. I've got a function named rotateDirection(float sourceAngle, ...
4
votes
3answers
120 views
Need a better function for transportation efficiency
I'm making an economic kind of game, and one of the things I'm simulating is the transportation of resources to a central depository, e.g. moving metal from a mine to the city (so it can be turned ...
5
votes
1answer
954 views
Rotate object to face player
This is probably a simple vector question, but I'm not sure how to do it.
I have an object at vector position (ox,oy). Potentially every update, the user walks around the screen, and will be at ...
3
votes
2answers
225 views
Compress the variance in a set of numbers?
I'm not sure if there's a better way to ask that, but I have a hovercraft which hovers by imparting force at each of four corners. I'd like to clamp the maximum variance between the thrusters so if ...
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
...
11
votes
6answers
3k views
Math topics for 3D graphics programming
I understand that the following math topics are required for 3D graphics programming. I have started doing some of them in my math course. Can someone point me in the direction of a resource that ...
10
votes
3answers
482 views
Animated examples of different interpolations formulas: any link?
I remember having spotted a link to a huge page with different equations to non linear interpolation curves, for example if you want to stop a car smoothly, etc.
Those can sometime be useful to ...
3
votes
1answer
340 views
How do I find the largest circle possible in a square of pixels using Unity?
As I am using Unity, I can easily grab a square of pixels of any length. However, I want to find the largest circle possible within that square of pixels.
So for instance, if I had a 40 x 40 square ...
0
votes
1answer
300 views
Surface of Revolution with 3D surface
I have to use this function to get a Surface of Revolution (homework).
newVertex = (oldVertex.y, someFunc1(oldVertex.x, oldVertex.y), someFunc2(oldVertex.x, oldVertex.y));
As far as I know (FIXME) ...
5
votes
3answers
197 views
Preventing ties
I'm working on a simple game to rate a users' preference among several styles. There are C classes, and the game consists of R rounds of comparison. At each round, the user is presented a ...
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 ...
4
votes
3answers
565 views
Kepler orbit : get position on the orbit over time
I'm developing a space-simulation related game, and I am having some trouble implementing the movement of binary stars, like this:
The two stars orbit their centroid, and their trajectories are ...
9
votes
4answers
349 views
What exactly causes a surface to overlap another?
I cannot really figure out what causes one surface to overlap another. In a 3D engine I'm creating, my technique is failing in edge cases.
My method is sorting the surfaces to be painted from the ...
28
votes
3answers
2k views
A ball hits the corner, where will it deflect?
I need to brush up my trigonometry and hope you can help here with a simple mathematical model. Here is my model so far in the image attached. I am aware that the frame animation has other problems ...
2
votes
1answer
364 views
Calculating camera zoom value (top-down)
I need some help in 'camera maths'. I have a birds eye view of two characters. One character is static and the other can move. I would like the camera to always show both characters in full and, in ...
5
votes
1answer
238 views
Realistic damage
I'm looking for a good way to simulate damage, for example a weapon firing at a ship it would calculate the damage depending on layer type, weapon type, angle and similar what i need is a way to to ...
1
vote
3answers
465 views
Get intersection of vector in the middle of the screen
My screen resolution is 640x480 and I have two Vector2 objects located at (10,10) and (600, 320).
How can I connect these two objects and extend the line to encompass the whole screens width, how can ...
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 ...
3
votes
1answer
2k views
How to create a perspective field of view matrix?
Hey, hello. I am learning a little of WebGL (OpenGL ES 2.0) through the http://learningwebgl.com tutorials, but it uses a third party library to create the View, Projection and transformation matrices ...
5
votes
2answers
808 views
Arrays for a heightmap tile-based map
I'm making a game that uses a map which have tiles, corners and borders. Here's a graphical representation:
I've managed to store tiles and corners in memory but I'm having troubles to get ...
14
votes
6answers
9k views
Best C++ Math Library for Game Engine? [closed]
I'm looking for a fast opensource C++ math-library for my game engine
with the following features:
fast (sse?)
vectors
matrices
quaternions
suitable for both opengl and directx
4
votes
1answer
215 views
Projecting onto different size screens by cropping
I am building a phone application which will display a shape on screen. The shape should look the same on different screen sizes. I Decided the best way to do this is to show more of the background on ...
5
votes
3answers
3k views
building a game for different resolution phones
I am starting some tests for building a game on the Android program.
So far everything is working and seems nice.
However I do not understand how to make sure my game looks correct on all phones as ...
6
votes
2answers
458 views
Calculating and detecting curves
How can I detect the 'steepness' of a curve? For example, if the user swipes their finger across the screen in a curve, what's the best way of detecting whether the curve is almost a semi-circle, or ...
4
votes
4answers
850 views
Physics timestep questions
I've got a projectile working perfectly using the code below:
//initialised in loading screen
60 is the FPS - projectilEposition and velocity are Vector3 types
gravity = new Vector3(0, ...
2
votes
1answer
428 views
Calculate the initial velocity of a 3D trajectory
I've got a 2D projectile code sample working, but would like to extend it to 3D. How would I calculate the initial velocity of the Z-axis? At the moment, I've got:
initVel.X = (float)Math.Cos(45.0);
...
3
votes
3answers
588 views
Restrict movement within a radius
I asked a similar question recently but now I think I know more about what I really want to know. I can answer my own question if I get to understand this bit.
I have a situation where a sprite's ...
2
votes
3answers
1k views
2D shader to draw representation of rotating sphere
I want to display a 3D textured sphere, and then rotate it in one direction. The direction will never change, and the camera will never move. One way is to actually create a spherical mesh, map a ...
3
votes
3answers
291 views
Adding 'swerve' to a direction
I'm not much of a maths expert, so this is probably quite straight forward. I was playing a soccer flash game where you take free kicks. You provide Power, Swerve and Direction. I'm reading up on ...
2
votes
3answers
340 views
Blending animations for more character movements
I am making a hack n slash 3rd person game, and I want the character movements to be more dynamic not like fighting games where you have a moves list.
I want to animate tons of different animations ...
3
votes
1answer
247 views
Approximating walking physics via simpler sliding physics
I am modeling walking insects. I implement them as cuboids and use forces (including friction and drag), to control motion. However, the movement characteristics of this 'sliding box' physics don't ...
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 ...
6
votes
1answer
1k views
Atmospheric Scattering
I'm trying to implement atmospheric scattering based on Sean O`Neil algorithm that was published in GPU Gems 2. But I have some trouble getting the shader to work. My latest attempts resulted in: ...
1
vote
1answer
332 views
Mandelbrot set not displaying properly
I am trying to render mandelbrot set using glsl. I'm not sure why its not rendering the correct shape. Does the mandelbrot calculation require values to be within a range for the (x,y) [ or (real, ...
1
vote
2answers
2k views
Voronoi regions of a (convex) polygon
I'm looking to add circle-polygon collisions to my Separating Axis Theorem collision detection.
The metanet software tutorial (http://www.metanetsoftware.com/technique/tutorialA.html#section3) on ...
11
votes
5answers
545 views
Is there a common word that encompasses handling of position, rotation, and scale together?
I'm looking for a name for my class that manipulates 4x4 matrices that handle position, rotation, and scale. Is there a common word that encompasses all three?
(I'm splitting the matrix math into its ...
11
votes
5answers
5k views
Complete Math Library for use in OpenGL ES 2.0 Game?
Are you aware of a complete (or almost complete) cross platform math library for use in OpenGL ES 2.0 games?
The library should contain:
Matrix2x2, Matrix 3x3, Matrix4x4 classes
Quaternions
...
13
votes
8answers
4k views
How should I sort images in an isometric game so that they appear in the correct order?
This seems like a rather simple problem but I am having a lot of difficulty with it.
What should I do to properly sort images in an isometric game?
In a normal 2d top-down game one could use the ...
6
votes
5answers
2k views
Changing coordinate system from Z-up to Y-up
Blender's coordinate system is different from what I'm used to, in that Z points upwards instead of Y. What would be the simplest way of converting all the world data (so that all animations, texture ...
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 ...
4
votes
2answers
389 views
How to detect and collide two elastic line segments?
There are 4 moving physical nodes in 3D space. They are paired with two elastic line segments / strings (1 <-> 2; 3 <-> 4).
Part I: How to detect the collision of two segments?
Part II: On the ...
3
votes
1answer
371 views
XNA - Weird bug with 2D Sprite Rotation
I have a problem with my XNA Game, I have a function where I need my sprite to face towards an enemy, using this code:
Vector2 currentPosition = Position;
Vector2 nearestEnemy = ...
1
vote
1answer
254 views
Frenet frame and application
I have just been reviewing Frenet Frame math. It is an interesting geometrical issue.
I know that common applications are:
camera movement along a curve
tube and ribbons surface
Can someone ...
4
votes
2answers
730 views
snapping an angle to the closest cardinal direction
I'm developing a 2D sprite-based game, and I'm finding that I'm having trouble with making the sprites rotate correctly. In a nutshell, I've got spritesheets for each of 5 directions (the other 3 come ...
5
votes
1answer
2k views
Ray Intersecting Plane Formula in C++/DirectX
I'm developing a picking system that will use rays that intersect volumes and I'm having trouble with ray intersection versus a plane. I was able to figure out spheres fairly easily, but planes are ...
3
votes
3answers
976 views
Basic tutorial/introduction for 3d matrices, idealy in c++, without openGl or directX
I am wondering if there is a simple tutorial that covers the basics of how to initialize rotation, translation and projection matrices, and how to multiply them, and how to get the screen coordinates ...
5
votes
1answer
676 views
How to calculate new direction after sprite collision
The scenario as you can see in the picture. A ball will be hitting a surface and I want to fairly correctly get the new angle after the collision..
I expect to know the X,Y coordinates of the lines ...
5
votes
1answer
381 views
What is the best way to limit player movement?
I'm currently programming a 2d game where the player moves around on a rectangular playing field. The player has a direction and a velocity. What is the best way to limit the player's movement so ...
