The circular movement of an object around a specific axis.

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1answer
2k views

Move an object by rotation AS3

I am currently trying to move an object (a square) around the stage in 2D space. Think Cuboid but in 2D platformer space, and vertical walls as well as the ground. The idea is that during each ...
2
votes
1answer
2k views

How to control a spaceship near a planet in Unity3D?

Right now I have spaceship orbiting a small planet. I'm trying to make an effective control system for that spaceship, but it always end up spinning out of control. After spinning the ship to change ...
4
votes
1answer
353 views

Clock hand, how much should I rotate the hand by every frame?

I've got a virtual clock. The clock consists of the actual clock sprite, and a hand to go over it. I'm able to set how long the clock duration is. Say I set it to: 5 seconds. While the clock time is ...
4
votes
3answers
600 views

How to calculate origin and position of a weapon which should be “in hands”?

I'm currently stuck with my game, which is from the top perspective. I'm currently using these sprites for player: (using the second at the top): And here's what I use for my gun My problem is ...
3
votes
4answers
817 views

Is it better to track rotation with a vector or a float?

In XNA, you can see that to draw a rotated sprite with SpriteBatch, you'll need a float describing the angle in radians. I'm used to making games in OpenGL. I just want a rapid prototyping ...
0
votes
2answers
1k views

from normal to rotation matrix

(i'm on OPENGL) i have a mesh O (object) and a mesh T (terrain). i know a single triangle in T and i want to orient O to be aligned to that triangle (torate O to align to T in that point). i have ...
3
votes
2answers
917 views

How can I make a sprite move in the direction it's facing using radians?

I am using PGELua for the PlaystationPortable. I would just like to know how to make a 2D sprite move in the direction that the sprite is facing. When the sprite is blitted to the screen it should ...
2
votes
1answer
602 views

Positioning a 2D image after rotation

Using SDL_gfx's rotozoomSurface function to rotate a 38x58 sprite....naturally when it rotates it creates a new surface with a new size, and the rotation isn't going around the center point. I am ...
4
votes
2answers
752 views

I need help with 2D collision response (of stacking rotating polygons, with friction and gravity, for a game)

Hi I am looking for suggestions on how to write a collision response for game programming purpose (so not a scientific simulation). I am dealing with 2D polygons that are rotating, and I want them to ...
2
votes
1answer
1k views

How can I create my mesh so that textures applied to it are NOT rotated 90 degrees in Unity 3D?

I'm trying a really simple test in Unity 3D. I want to render a texture on the simplest plane possible. So, I've created a two-triangle plane in Blender, then imported it into Unity. From there, I ...
1
vote
2answers
398 views

Creating a rotation offset based on camera position with XNA

I have an XNA project where characters have the ability to pick up and move objects around (in 3d). When an object is picked up by a character, I want ithe objects position to always be out in front ...
8
votes
4answers
12k views

How can I orbit a camera about it's target point?

I'm drawing a scene where the camera freely moves about the universe. The camera class keeps track of the view (or look at) point, the position of the camera, and the up vector. These vectors/points ...
3
votes
3answers
7k views

Bounding box of a rotated rectangle (2d)

I can see this has been asked before in various ways. I am struggling to work it out though hence asking again. 2d sprite that moves and rotates. I'm looking to contain it in a bounding box as it ...
3
votes
2answers
4k views

Cocos2d rotating sprite while moving with CCBezierBy

I've done my moving actions which consists of sequences of CCBezierBy. However I would like the sprite to rotate by following the direction of the movement (like an airplane). How sould I do this with ...
0
votes
1answer
368 views

vector rotations for branches of a 3d tree

I'm attempting to create a 3d tree procedurally. I'm hoping that someone can check my vector rotation maths, as I'm a bit confused. I'm using an l-system (a recursive algorithm for generating ...
5
votes
1answer
6k views

How to calculate a 3x3 rotation matrix from 2 direction vectors?

I've got 2 direction vectors, for the X axis and the Y axis of the object. How do I calculate the rotation matrix of the object using these?
1
vote
2answers
2k views

XNA advanced rotation 3D

I'm able to rotate any model with any angle I want, where I can not rotate my model around a given point. e.g: My model rotates from the origin assigned in its .fpx file. I want it to rotate related ...
6
votes
3answers
758 views

Why is my model's scale changing after rotating it?

I have just started a simple flight simulator and have implemented Roll and pitch. In the beginning, testing went very well; however, after about 15-20 seconds of constantly moving the thumbsticks in ...
24
votes
2answers
2k views

Calculating the rotational force of a 2D sprite

I am wondering if someone has an elegant way of calculating the following scenario. I have an object of (n) number of squares, random shapes, but we will pretend they are all rectangles. We are ...
2
votes
1answer
603 views

Rotating a group of sprites - How to calculate origin

I am rotating a group of sprites in XNA, which I developed with the help of the following example: http://msdn.microsoft.com/en-us/library/bb194912%28v=xnagamestudio.10%29.aspx It all works very ...
9
votes
2answers
4k views

How can I rotate about an arbitrary point in 3D (instead of the origin)?

I have some models that I want to rotate using quaternions in the normal manner, except instead of rotation about the origin, I want it to be offset slightly. I know that you don't say, in 3d space, ...
2
votes
3answers
507 views

How should I model exact 90-degree rotations in 3D?

I'm familiar with quaternions... have used them in the past to model arbitrary rotations in 3D, as for a plane flying around with full pitch/yaw/roll freedom. Works great. Now I'm working on a 3D ...
0
votes
1answer
248 views

What is causing this problem with my object rotation?

I'm having an issue here with rotation in OpenGL. Before I changed my rendering function the rotation I had for my object worked fine, but now it seems to be messed up. I changed my rendering ...
2
votes
1answer
615 views

Image spinning in c#

I'm currently in the process of making a top-down shooter for my programming class, and one idea I had, but don't exactly know how to implement is image rotation in order to spin the object ...
2
votes
1answer
6k views

Rotating an object in OpenGL about it's centre

Im writing a game for which, one of the models are loaded from an .obj file. It's a model of a plane, and I want to rotate the propeller. The object file is broken into groups, and the propeller is ...
1
vote
2answers
2k views

How can I rotate a sphere in response to mouse movement?

I'm using jMonkeyEngine to develop a game. I'm good at scripting, but math usually goes over my head. I tried the Wiki page for Quaternion, but I was far too confused to figure this out myself :P My ...
2
votes
0answers
361 views

Programmatically determine UVs by rotating a plane along X axis

I'm having a math brainfart while trying to solve what might be a simple problem. I've got a plane in 3d space (it's actually the face of a 10-sided die): Coordinates [x,y,z]: Point_top = [0,0,1] ...
2
votes
3answers
490 views

Create quaternion based on where a unit is hit (shield effect as in Starcraft 2) [duplicate]

I'd like to implement a shield effect like that done for Protoss units in Starcraft 2. I'm guessing that the technique involved uses a partial sphere that is rotated to reflect where a unit is hit. ...
11
votes
4answers
4k views

How to rotate blocks in tetris

I have a gameboard grid which is 20 rows high and 10 columns wide with the origin (0,0) being in the top left hand corner. I have a tetrimino in play, which is composed of four blocks. I have the x,y ...
2
votes
1answer
721 views

Allegro 5 Mouse Look

I found good tutorial on how to do mouse look for 2D game here: http://www.atburrow.com/2010/03/08/objects-facing-the-cursor/ My code looks like this: w = (double)mouse_x - (double)pos_x; h = ...
3
votes
2answers
640 views

Quaternion understanding

I have some understanding problem concerning quaternions. In order to have my world object rotate in the correct way, I need to invert their quaternion rotation while refreshing the object world ...
1
vote
0answers
672 views

Rotation deforming mesh (Opengl ES 2.0)

I'm trying to render a rotating cube on Opengl ES 2.0, using some math classes I wrote (based on a lot of online and offline info) for quaternions, matrixes and the like. As far as I know all the math ...
2
votes
2answers
4k views

Rotate canvas along its center based on user touch - Android

I want to rotate the canvas circularly on its center axis based on user touch. i want to rotate based on center but its rotating based on top left corner . so i am able to see only 1/4 for rotation ...
8
votes
2answers
2k views

How do I rotate a structure of hexagonal tiles on a hexagonal grid?

My 2D isometric game uses a hexagonal grid map. In reference to the image below, how do I rotate the light blue hexagon structures by 60 degrees around the pink hexagons? EDIT: Main hex is (0,0). ...
4
votes
1answer
1k views

Turning a sprite such that it rotates in the direction that's most efficient

I have a sprite that moves from waypoint to waypoint. It turns to face its velocity vector, but not instantly (there's a rotation speed). The problem I'm having is, from one direction to another, the ...
1
vote
1answer
2k views

XNA - Use Mouse To Rotate & Arrow Keys To Scroll A Linearly Wrapped Texture:

Using XNA I'm working on my first, relatively simple, videogame for the PC. At the moment my game window is 1024 X 768 and I have a 'Starfield' linearly wrapped background texture 1280 X 1280 in ...
6
votes
2answers
693 views

AABB of rotated sprite?

Say I have a sprite. Its AABB is easy to find since I know the width and height. Say I rotate it 45 degrees, I don't think the AABB would be big enough to cover it, so I need a new AABB. How can I ...
9
votes
3answers
640 views

Can I use quaternions to control an helicopter?

I'm trying to make a simplified helicopter (for the moment, it's a cube) simulation in 3D and I'm having some problems with rotation. An helicopter can rotate along the three axes : rotate on itself ...
0
votes
2answers
486 views

CubeRealm OpenGL rotation problems, need help. :\

I'm totally new to OpenGL and I'm working on a Sandbox game called CubeRealm. My problem you see is rotation. I've got it in my head that to rotate the 'camera' I just rotate all the scene by the ...
2
votes
3answers
4k views

LWJGL glRotatef() without rotating axes?

Okay so, I noticed when you rotate around an axis, say you do this: glRotatef(90.0f, 1.0f, 0.0f, 0.0f); That will rotate things 90 degrees around the x-axis. However, it also sort of rotates the y ...
6
votes
2answers
850 views

What is eigenvalue decomposition and why would it be useful in games?

In various math libraries developed for game engines, I see 2x2 and 3x3 square matrices having this function (along with some helper functions). I tried to find information regarding it but did not ...
0
votes
3answers
5k views

How to rotate a rectangle?

I can easily rotate sprites using the Draw method. However I would like to simply rotate a Rectangle (the structure) so that I can get the coordinate of the four corners of the rectangle. How can I do ...
4
votes
4answers
5k views

GLM: Euler Angles to Quaternion

I hope you know GL Mathematics (GLM) because I've got a problem, I can not break: I have a set of Eular Angles and I need to perform smooth interpolation between them. The best way is converting them ...
0
votes
2answers
445 views

Linear Interpolation Causing Gimbal Lock?

I have created an object movement path in a 3D authoring application. Then, I exported the path (100 frames) into my custom text file in the form of Euler Angles. The next point was loading the ...
1
vote
0answers
708 views

Remove rotation on bones in 3DS Max 2009

I was given a model by an artist and it was boned and skinned for me. The .max file that he provided also included an animation to show what he would be able to do. (A basic running animation.) ...
4
votes
4answers
2k views

Need a good quality bitmap rotation algorithm for Android

I am creating a kaleidoscopic effect on an android tablet. I am using the code below to rotate a slice of an image, but as you can see in the image when rotating a bitmap 60 degrees it distorts it ...
1
vote
2answers
411 views

opengl rotations for a human

I currently can rotate around a pivot point by first translating to the pivot point then performing the rotation and finally translating back to the origin. I do that easily enough for the shoulder in ...
1
vote
2answers
467 views

Rotating coordinate system

Lets say that you want to rotate simple cube around fixed point in center. Is it possible to use such coordinate system, that you need to use only sine and cosine in order to rotate? I have done ...
2
votes
4answers
3k views

per pixel based collision detection

I was wondering if anyone had any ideas on how to get per pixel collision detection for the android. I saw that the andEngine has great collision detection on rotation as well but couldn't see where ...
6
votes
1answer
2k views

Rotation of bitmap using a frame by frame animation

I have one large bitmap that has four frames drawn on it and I only draw one at a time by looping through the bitmap by increments to animate walking. I can get the bitmap to rotate correctly when it ...