# Tagged Questions

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.

96 views

### Game maker, issues with an equation

Hello I am having an issue getting this equation to work, even with manually entering values replacing the variables. I cannot seem to get it to work, I have tested that the variables are being ...
195 views

### In a semi-infinite procedural (chunk based) map, how do you handle objects larger than a single chunk?

I'll use an example to try and be more specific. Assume this is for a 2D top-down game. Chunks in this are made up of 32x32 tiles. If procedural buildings were to be generated based on some kind of ...
75 views

### Tennis game algorithm and maths

Tennis courts are real dimensions and game is 3D Ball has position (x,y,z), speed(vx,vy,vz) and acceleration (ax,ay,az) Game has 30 fps and on each update (1/30sec) it has these properties vx +=ax; ...
39 views

### Good way to integrate time to a quiz game [closed]

I wasn't sure which stack exchange site to pose this question to, so I'm asking it here, I hope it's appropriate. This thing I'm writing for fun is basically a mental math speed quiz game. I'm writing ...
96 views

### very simple math destination and speed calculation

My player goes to (destinationX, destinationY) His position is: (x,y) and the player has an update event function update() { this.x = this.x + dx; this.y = this.y + dy; } what is the formula ...
72 views

### Trying to project a point onto a cubemap

I've got a simple test program with a camera within a cubemap (skybox). You can look around, and it feels like you're in a 3D room, but really it's just a cubemap image. Now I want to draw a point ...
1k views

### Why are radians preferred over degrees in game development?

I've been looking up the definition of radians and found out that mathematicians prefer them because they are derived from pi instead of being completely arbitrary like degrees. However, I have not ...
182 views

### Are there multiple valid definitions for what translate, rotate and scale do?

Are there multiple valid definitions for what translate, rotate and scale do to the 4x4 matrix? I bring up this question, because I have a simple webgl program that draws a square and does a few ...
80 views

### Rotating one object to track another in worldspace

This should be pretty straightforward, but its been awhile and my brain has officially turned off for the holidays :-) To keep things simple, lets assume everything is in 2D space. I've got a large ...
119 views

### breakout game, computing optimal ricochet angle of a ball to get to a certain point

perhaps the title isn't clear so here is an explanation with a picture to better express my question Consider the following breakout clone game where the game is rigged to change the ricochet ...
97 views

### How can I determine trajectory from distance and time, without initial velocity?

I'm attempting to develop a Mortar that needs to lead it's shot to the target enemy. The shot will have a pre-determined constant flight time of (2.5 seconds) and it will have where the enemy should ...
63 views

### Shape collision checking

I want to check in an shape, wether an point is in it or not. The shape is descriped with one Array of float vectors. The vectors are added in clock direction. The first I can check very easy, the ...
83 views

### Floating point memory usage on gpu

My question is simple: how much memory on GPU does one floating point value takes? I guess it is 4 bytes, but I'm not sure. So for example is it true that vec4, which holds 4 floats, each 4 bytes ...
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### Implementing frame-independent friction

So I'm not looking for anything realistic like a physics engine, just want to say that first. I'm working on a simple top-down game and I'm trying to get friction working with deltaTime. This was my ...
391 views

### How to rotate an object around world aligned axes?

I have a Vector3 which has an euler angle for each axis. Usually, when I want to create a rotation matrix I will use functions such as D3DXMatrixRotationX passing the respective angle from my ...
147 views

### Ray picking and bounding boxes in Java

How do I check which bounding boxes (of different types) a ray, sent from the camera through the mouse-click coordinates, intersects with first in Java (and where)? I have arrays (box_X, box_Y, box_Z, ...
80 views

### Animation is too fast

I have an animation of a bullet but it seems to be going much faster than i was expecting. I currently set it to 0.5 pixels per second yet it seems to be moving way over hundreads of pixels per ...
158 views

### Do videogames use numerical solutions? [closed]

Do video games often use numerical solutions in their calculations, such as you might generate using software like MATLAB or Mathematica? Perhaps for making formulas for AI, or for game physics ...
122 views

### Predicting trajectory collisions for multiple moving objects [duplicate]

For the most simple of 2D games, I have implemented a posteriori collision detection (overlapping rectangles) on the xy Cartesian plane, but am now interested in understanding the basics of a priori ...
35 views

### Sprite rotation algorithm [duplicate]

I'm making a game where you have to plot a function to hit certain objectives. I already made the plotting function and the animation to display a tiny missile that travels above the function. My ...
177 views

### Finding roots/zeros for collision detection?

For the most simple of 2D games, I have implemented a posteriori collision detection (overlapping rectangles) on the x/y Cartesian plane, but am now interested in understanding the basics of a priori ...
146 views

### How can I implement jumping in a 2D game using bounding box collision?

Problem: I'm trying to implement basic jumping to my 2D game engine, but have failed several times. Basically what I've done so far is disabling gravity and using a separate function moving the player ...
43 views

### Rotating a joint to a desired angle

I would like to set the speed of my box2d revolute joint each update such that it will rotate to a desired angle and stop. My first thought was just to set the speed to +max or -max based on the ...
65 views

### Divide rectangular image into fixed number of random sized rectangles + 1 fixed size rectangle

I'm trying to divide a rectangular image into a fixed number of smaller rectangular image parts (of random but bounded width / height), with the exception of 1 rectangle which is predefined in ...
47 views

### Percentages for different platform generation [duplicate]

I have a level manager, which creates levels and levels create platforms. Levels can contain a variety of platforms. I dont really understand how I can say: I want a 10% of one platform being ...
95 views

### How do I smooth out of the effects of a too-sensitive control?

I have a game that takes input from a joystick. If you tilt the joystick right, the ship moves right linearly according to how much the joystick is tilted. So if you tilt the joystick twice as much ...
178 views

### How to detect collision between a camera and a mesh?

I am wondering how you would be able to extract mesh properties (i.e. faces, vertices, and vertex normals) and use them to create a collidable object, one that a camera can't go through ? I am using ...
202 views

### How to move an object up and down like a wave?

I am trying to move my object up and down using cos and sin, but I have problem understanding how does the sin and cos work, so I can make my object move up and down like a wave frequently Init Time ...
40 views

### Find angle between two points in java [duplicate]

I am making a very simple game and want the hunter to shoot the dragon when the player touches on the screen. I want the arrow to be craeted at hunterPosition.x and hunterPosition.Y and move towards ...
188 views

### Circle to Circle collision - bad accuracy

Circle1 (blue) is moving and its X and Y bounds are the screen (meaning it bounces off the walls). Circle2 (black) is stationary. Circle1(blue) is supposed to bounce off of Circle2 without ...
80 views

### How to aim with a spaceship in 3D considering its angular momentum?

So I have a spaceship and I have 6 degrees of freedom. At a given moment the following vectors are known of the spaceship: Local forward. Local up. Local sideways (may be implied from the previous ...
134 views

### Math > Logic for a Logarithmic Score Meter

I'm trying to implement a score meter whereby I specify a maximum value (say 15,000) and I can render values on it in a logarithmic manner ie: +------+---+--+-++ +------+---+--+-++ |== ...
123 views

### Isometric Movement in Javascript In the DOM

I am creating a game using Javascript. I am not using the HTML5 Canvas Element. The game requires both side view controlles, and Isometric controls, hence the movementMode variable. I have got the ...
190 views

### Project collision shapes to plane for 2.5D collision detection

I am working on a top down 2.5D game. In the game anything that overlaps on the screen should be 'colliding' with each other regardless of whether they are on the same plane in the 3D world. This is ...
113 views

### Bouncing off a circular Boundary with multiple balls?

I am making a game like this : Yellow Smiley has to escape from red smileys, when yellow smiley hits the boundary game is over, when red smileys hit the boundary they should bounce back with the ...
356 views

### Quaternion LookAt for camera

I am using the following code to rotate entities to look at points. glm::vec3 forwardVector = glm::normalize(point - position); float dot = glm::dot(glm::vec3(0.0f, 0.0f, 1.0f), forwardVector); ...
58 views

For a while now I used PCSS for my shadow technique of choice until I discovered a type of percentage closer filtering. This method creates really smooth shadows and with hopes of improving ...
132 views

### Camera movement with slerp

I have 3 spots, I would like to move my camera to using slerp. Just As seen in the image below. My question is how I can connect my camera to the first spot? I should be able to move between other ...
81 views

### Help with timebased scoring algorithm

Im trying to devise an appropriate scoring system for my game. The game in essense has a finite number of tasks to complete (say 20) and the quicker you complete these task, the more points you get. ...
331 views

### Slerping rotation mirrors

I rotate my game character to watch at the target using the following code: transform.rotation = Quaternion.Slerp(startQuaternion, lookQuaternion, turningNormalizer*turningSpeed/10f) ...
376 views

### How to balance experience gain in an RPG

I am currently developing an RPG game with a classic experience-points and levelup mechanic. The player kills monsters, gains experience points, levels up when they collect enough and become stronger. ...
153 views

### Vector normalization gives very imprecise results

When I normalize vectors I receive very strange results. The lengths of the normalized vectors range from 1.0 to almost 1.5. The functions are all written by me, but I just can't find a mistake in my ...
180 views

### JavaScript 3D space ship rotation

I am working with a fairly low-level JavaScript 3D API (not Three.js) which uses euler angles for rotation. In most cases, euler angles work quite well for doing things like aligning buildings, ...
102 views

### Automatically zoom out the camera to show all players

I am building a game in XNA that takes place in a rectangular arena. The game is multiplayer and each player may go where they like within the arena. The camera is a perspective camera that looks ...
58 views

### Perspective projection computation

I'm learning OpenGL from arcsynthesis and I don't understand something about perspective projection (http://www.arcsynthesis.org/gltut/Positioning/Tut04%20Perspective%20Projection.html). When the ...
151 views

### How to Construct a Perspective Projection With 4 Vanishing Points

Is it possible to construct a projection matrix which will create a perspective with four (or more) vanishing points? This question have an OpenGL tag, but general insights are welcomed as well.
268 views

### The physics equation for a perpetual seesaw

I am trying to create a game that involves two or more people jumping on a seesaw and propelling each other in the air. I need help with the physics equations Assume no friction and no air ...