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.
0
votes
0answers
52 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 ...
3
votes
3answers
194 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 ...
4
votes
1answer
187 views
deferred rendering and point light radius
I use a common attenuation equation for point lights:
attenuation = 1 / kc + kl * d + kq * d^2.
I use deferred rendering so I need to know a light radius. An example light has following intensity: ...
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 ...
5
votes
1answer
373 views
3D isometric depth sorting
How is it possible to depth sort tiles and objects in an isometric environments without any limitations? I've been researching this for a while now and there seems to be no publicly available answers ...
0
votes
0answers
97 views
How to predict encounters between a ship and a body's sphere of influence in 2D
Long time listener, first time caller. I'm making a little hobby game in XNA, its about transport ships in space, analogous to container ships at sea. There are to be AI ships and player controlled ...
0
votes
1answer
295 views
How to extract euler angles from transformation matrix?
I have a simple realisation of entity/component game engine.
Transform component have methods to set local position, local rotation, global position and global rotation.
If transform is being set new ...
11
votes
8answers
854 views
Converting a 2D curve into points for data storage
I’ve created an algorithm which converts any curve i.e. path into minimum number of points so that I can save it into a file or database.
The method is simple: it moves three points in equal steps ...
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 ...
1
vote
2answers
107 views
Accumulating rotations for camera
It seems there are three ways to store a camera's rotation: in angles, view matrix or quaternion. I was using euler angles since when I used a matrix it had a tendency to accumulate rounding errors ...
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 ...
-1
votes
1answer
150 views
Camera not working
I made a camera in DX9. To move forward I press the Up arrow. To rotate on the Y axis I use the mouse. When I perform these movements on their own the camera moves at the speed I want.
However, if I ...
0
votes
1answer
65 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
2answers
179 views
How to build a math module and simulate a system?
For example, in the classical game SimCity:
an economic model to simulate the supply and demand of the city, then calculate how many people live in each building, how many people work there.
a ...
4
votes
1answer
217 views
2D car physics and high speed turning
I've been looking at the following page, which has been very helpful: http://www.asawicki.info/Mirror/Car%20Physics%20for%20Games/Car%20Physics%20for%20Games.html but have come into problems with the ...
4
votes
2answers
191 views
Defining an OpenGL unit
I have read that you can define your OpenGL unit by using glViewport.
As far as I understood if you use something like glViewport(0,0,600,600) then 1 OpenGL unit = 600 pixels. Now my problem is what ...
3
votes
2answers
223 views
How to implement armor? [closed]
I am a newbie in Python, I am very bad at math too and I need some help. Also close/move this post if you feel this isn't the right place for it.
Hero1 = 5000 # His HP is 5k.
Hero1dmg = 200 # ...
2
votes
2answers
171 views
Why does matrix multiplication lead to different result if it's done on CPU, compared to GPU(shader)?
If I'm calculating a "camera space" on the CPU, by multiplying the view with the projection matrix on the CPU , and afterwards multiplying the world to the result my vertices do not pass to the pixel ...
3
votes
1answer
61 views
Matrix Translation Transformation Question
I've been reading a lot about computer graphics lately and because of it I'm building my own math library's for fun. I was reading about Matrix Translation and Homogeneous Coords, and was wondering ...
2
votes
1answer
178 views
Get intersected volume of two planes in 3D
I'm working on AABB - AABB collision response and I'm having trouble figuring one part out. My situation is as follows (see image).
I have a player AABB (blue) and an object which collides (brown). ...
5
votes
3answers
259 views
How can I change the acceleration of an object to arrive at a particular time?
I'm trying to write some code to change an acceleration factor so a ball will arrive at a destination in a desired time.
The problem is I don't know time (t) but I do know I want it to arrive at (t - ...
1
vote
1answer
92 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 ...
4
votes
1answer
201 views
What happens to data between vertex shader and pixel shader?
Short version: What can happen to the output of a vertex shader that leads to no(or very few) pixels being drawn, especially in relation to a perspective matrix.
Long version:
My problem refers to ...
5
votes
1answer
202 views
A* for non grid network
For my specific case, I am trying to find a path finding implementation similar to what described here.
I could see reference implementation for A* and HPA*, but I wonder how to extend A* to simple ...
1
vote
1answer
155 views
Creating a frustum for culling in world-space glm matrices
I need to do frustum culling where the bounding boxes are in world-space to determine which entities get to be updated/drawn. I was trying to use the classic projection/view matrix plane extraction ...
12
votes
5answers
2k views
What is the purpose of the canonical view volume?
I'm currently learning OpenGL and haven't been able to find an answer to this question.
After the projection matrix is applied to the view space, the view space is "normalized" so that all the points ...
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 ...
1
vote
5answers
316 views
how to rotate enemy to face player? [duplicate]
Okay so i havebeen rotating my enemy to face the player using
float targetrotation = Math.Atan2(playerpos-enemypos);
enemy.rotation = targetrotation; (<this line of code i want to change)
This ...
1
vote
1answer
209 views
Point inside Oriented Bounding Box?
I have an OBB2D class based on SAT.
This is my point in OBB method:
public boolean pointInside(float x, float y)
{
float newy = (float) (Math.sin(angle) * (y - center.y) + Math.cos(angle) *
...
0
votes
4answers
202 views
A formula for point calculation based on value A's proximity to value B
I am trying to find a formula to use for my rhythm game's scoring. Basically there is a Guide entity and a Live entity. You control the Live entity and have to match it as closely as possible to a ...
0
votes
1answer
83 views
Jump function of player [duplicate]
I'm developing game in marmalade sdk in c++. I have player in the area.and I wanna make him jump when i pressed a button.When I use this player.moveUp(5px); it just go up 5px, but he has to fall down ...
0
votes
3answers
95 views
How to calculate size of object depending of its height on the screen?
I am programming a mostly 2D game on Android (with Andengine), but the player is a bouncing ball (kinda in 3D).
I wanted to make the bouncing of the ball the most realistic possible, using quadrilic ...
5
votes
2answers
146 views
Plotting entities on a radar
I'm trying to build a radar system like the one in the original X-Wing games. The way it works is that there are two circular radar systems, one for behind the ship, and one for infront.
So, I've ...
1
vote
1answer
56 views
Build a Cube/Prism from other varied Cubes/Prisms [closed]
I'm wondering, are there any algorithms or theories in existence (that aren't patented/proprietary/protected) that would take a series of 3d rectangular prisms (or cubes but a cube is a prism) and ...
2
votes
1answer
113 views
AABB of a sphere's screen space projection
What is a nice, neat way to get the AABB of a sphere's projection onto the screen? This is to determine simplified geometry for lights in deferred shading.
-3
votes
1answer
246 views
Getting the normals of a hemisphere?
I'm trying to calculate the normal for a hemisphere.
I draw the hemi-sphere by this code:
for(float phi = 0.0; phi < 1.567; phi += factor) {
glBegin(GL_QUAD_STRIP);
for(float ...
3
votes
3answers
134 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 ...
1
vote
2answers
127 views
Distribute circles evenly on Screen - circle packing
I want to evenly distribute a random amount of circles with random diameter on the screen for. This level doesn't scroll so the users screen resolution sets the limits. Further I would like the ...
8
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 ...
2
votes
2answers
304 views
Bezier curve not drawn correctly
I'm trying to draw a bezier curve using 3 points. If I use the quadratic form:
I get this result:
And I believe it's correct.
Now since I need to draw it with a variable number of points, ...
2
votes
1answer
99 views
Physics movement prediction is way off [closed]
I'm making a simple, non-networked game. There are two players and a ball. In implementing the AI for the second player, I've run into a huge problem predicting where the ball will hit the ground. ...
0
votes
1answer
77 views
Increase restitution (bounciness) of an object in a JavaScript formula
I'm going slightly around the houses on this one. I originally started a thread over on Stack Overflow about it but then it seemed to diverge into mathematics, with no joy from the SO community over ...
0
votes
0answers
39 views
Cascaded Shadow Maps left handed to right handed coord system
Im trying to port the Directx SDK (june 2010) sample (CascadedShadowMaps11) into a right handed version (to later implement in my engine) but i can't figure out the math, so far i got it partially ...
6
votes
2answers
322 views
How can you extract orientation from a transformation matrix?
I have a 4x4 transformation matrix M, and I want to find out the shape of a sphere when transformed by M. (Sphere is at the origin and has radius 1.)
I know I can find the center by just multiplying ...
3
votes
2answers
256 views
How do I calculate consistent frame timings at 60fps?
I'm writing an HTML canvas game that uses requestAnimationFrame and therefore runs at 60fps, although this is more of a question about failing arithmetic than about JavaScript.
If I measure the time ...
2
votes
1answer
176 views
How to rotate a direction
I'm working a spotlight for my deferred renderer and I'm having trouble with matching the mesh to the visual representation of the light. Right now my mesh is a cone, the apex of the cone is at ...
0
votes
1answer
203 views
How do I detect the intersection of a curve with itself?
I'm developing a game in which the player can draw a line. I want to detect if that line intersects with itself. How would I do this?
-2
votes
1answer
117 views
In a regular grid, how can I tell which tile a position is in?
I have a position on the screen, how do I calculate which grid tile that position is inside?
I know the number of tiles in the grid, and the size of the screen (including how many tiles fit on it ...
1
vote
1answer
150 views
Any book about math in game design? [closed]
Game designers need math as one of their tools for designing game, unfortunately I can't find one book concentrate on this topic. I know there's math book about game programmer, but designer need ...
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.
...
