Tagged Questions

1
vote
0answers
41 views

Numerically stable(ish) method of getting Y-intercept of mouse position?

I'm trying to unproject the mouse position to get the position on the X-Z plane of a ray cast from the mouse. The camera is fully controllable by the user. Right now, the algorithm I'm using is... ...
2
votes
4answers
286 views

Simulating a sine wave/oscillating pattern for enemies

I'm creating a simple top down shooter, right now I have an enemy which simply follows the player. I'd like to change things up and have the enemies move towards the player but in a wave like motion. ...
1
vote
2answers
113 views

How to offset particles from point of origin

Hi I'm having troubles off setting particles from a point of origin. I want my particles to spread out after a certain radius from a the point of origin. For example, this is what I have right now: ...
2
votes
2answers
162 views

Calculating the correct particle angle in an outwards explosion

I'm creating a simple particle explosion but am stuck in finding the correct angle to rotate my particle. The effect I'm going for is similar to this: Where each particle is going outwards from the ...
-1
votes
1answer
201 views

Breakout… Getting the ball reflection X angle when htitting paddle / bricks

Im currently creating a breakout clone for my first ever C# / XNA game. Currently Ive had little trouble creating the paddle object, ball object, and all the bricks. The issue im currently having is ...
3
votes
1answer
255 views

Finding closest object to a location within a specific perpendicular distance to direction vector

I have a location and a direction vector indicating facing, I want to find the closest object to that location that is within some tolerance distance (perpendicular distance) to the ray formed by the ...
1
vote
0answers
462 views

Interpolation between two 3D points?

I'm working with some splines which define a path a character follows (you can see a gameplay video here to get a better understanding of what's going on: http://www.youtube.com/watch?v=BndobjOiZ6g). ...
3
votes
2answers
240 views

Tessellating/Subdividing a quad

I am creating a quad that starts as a single quad, then divides itself multiple times (from 1 -> 4 -> 16 -> 64 -> 256 etc) but I have encounted an issue. When I get to 64 sub divisions only 16 quads ...
2
votes
1answer
255 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 ...
2
votes
1answer
241 views

Moving two objects proportionally

I'm trying to move two objects away from each other at a proportional distance, but on different scales. I'm not quite sure how to do this. Object A can go from position 0.1 to 1. Object B has no ...
1
vote
1answer
648 views

Line segment / circle intersection - X value seems wrong?

Major Edit I'm making a Breakout clone, and having difficulty with collision detection between a circle and line segment. Apologies, my earlier question was a result of frustration and no sleep :) ...
6
votes
1answer
2k 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 }.
3
votes
3answers
2k views

Getting the angle between two objects?

I have a set of boxes which create a sort of path, they don't intersect very smoothy and to help that process I'm trying ot find a way to get an angle between them that can make it easier to generate ...
1
vote
1answer
158 views

An ellipse outside two points?

I am trying to generate an ellipse outside two points (two-dimensional vectors). Is there a formular for that, or a cool way of doing that in C# XNA? What I am trying to do is have a particle circle ...
3
votes
4answers
401 views

Vary speed of enemy smoothly

Hey. I'm trying to create an enemy that travels at a speed s on screen but I'm having trouble with trying to make the speed vary in a smooth motion. Basically, I can get the enemy to move at a ...
5
votes
1answer
634 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 ...
8
votes
1answer
747 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 ...
2
votes
1answer
305 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
2answers
743 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 ...
3
votes
3answers
402 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 ...
4
votes
2answers
621 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 ...
3
votes
1answer
221 views

Correct Blitting 2 surface problem

this is a graphics/math problem. Consider this 2 sprite / surface As you can see they are a tank and his gun turret. Now, i manage the turret rotation, and it works, and, also, the rotation of ...
20
votes
3answers
2k views

Is there a faster sine function?

I am working on generation 3d perlin noise. The C# Math library seems like overkill for what I need since most of its functions use double percision. I use Math.Sin() in several places to generate the ...
5
votes
1answer
644 views

Zooming and panning a camera simultaneously causes a swooping effect

In a 2d game, I have a basic camera class. The guts of the class creates a transformation matrix that is later passed to the Begin() method of a SpriteBatch. The transformation is done like this: ...