Rotation is the circular movement of an object around a specific axis.

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1answer
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Moving a rotated model in XNA

This seems like a simple problem with an equally simple solution that is invisible to me. I have a model that spawns at the origin and looks at my player model wherever it goes. I would like it to ...
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4answers
2k views

Rotating a model AND translating it forward in XNA

I have this enemy class, and I want it to 1) Spawn at a certain place Vector3 pos 2) Rotate to face my player position 3) Move forward As this code is now, it will appear at it's specified place: ...
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2answers
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Calculating a quaternion so a bone points in a specified direction

In an attempt to solve this question, I decided to figure out the absolute (world space) directions of each joint in the source pose (as normalized unit vectors), and then rotate the joints of the ...
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1answer
816 views

Camera Rotation (for mouse look) with LookAt does not work as expected (Local/Global)

My code for rotating my 3D fps camera isn't working as expected. I expect that the X-axis does rotate with the Y-axis, but it ain't so. I made some pictures to explain it better, I think its doing ...
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1answer
116 views

Creating a 2D Line Branch (Part 2)

Yesterday i asked this question on how to create a 2D line branch; Creating a 2D Line Branch And thanks to the answered provided, i now have this nice looking main branch; *coloured to show the ...
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1answer
1k views

Flip rotation matrix

I'm doing character control with kinect. I need to mirror the joint orientation because the character faces the player. Somehow by Googling through internet I've done it and everything works very ...
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2answers
1k views

Simple thruster like behaviour when rotating sprite

I'm prototyping some 2D game concepts with XNA and have added some basic keyboard inputs to control a triangle sprite. When I press key up the sprite accelerates in it's current facing direction, ...
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2answers
818 views

Matrix rotation of a rectangle to “face” a given point in 2d

Suppose you have a rectangle centered at point (0, 0) and now I want to rotate it such that it is facing the point (100, 100), how would I do this purely with matrix math? To give some more specifics ...
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2answers
584 views

Passing an objects rotation down through its children

In my topdown 2d game you have a player with a sword, like an old Zelda game. The sword is a seperate entity, and its collision box "rotates" around the player like an orbit, but always follows the ...
4
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1answer
687 views

Arcball Problems with UDK

I'm trying to re-create an arcball example from a Nehe, where an object can be rotated in a more realistic way while floating in the air (in my game the object is attached to the player at a distance ...
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1answer
413 views

OpenGL: Rotating cannon about non-centre position?

So I have a "cannon" object (basically a long cylinder) and I want to be able to control its angle. The code I have now is: glPushMatrix() glTranslatef(self.position.x,2.5,self.position.z) ...
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5answers
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How to make something rotate a certain amount over an exact amount of time

I'm trying to make a plane rotate down a certain amount and 180 degrees horizontally over 2 seconds. Basically I want it to take the plane 1 second to rotate to a horizontal-facing angle, then take ...
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votes
3answers
751 views

Rotate a particle system

Languages / Libraries in use: C++, OpenGL, GLUT Okay, here's the deal. I've got a particle system which shoots out alpha blended textures to produce a flame. The system only keeps track of very ...
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1answer
2k views

Moving an image by rotating and increasing y axis causes a trailing issue

Forgive me if me anything is unclear, this is a tricky thing for me to explain. In an applet I draw a little ship gif. I have it so I can rotate the object and then increase or decrease the y axis to ...
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2answers
885 views

Transformation order when dealing with Meshes

I have created a player model out of primitive types. To do this I have created a Model class and Component (mesh) class. Each model consists of one or more components my problems start when you have ...
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3answers
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Can I use SpriteBatch when drawing sprites on a rotating 3D plane

I'd like to have my plane of sprites rotate similarly as in this game (YouTube Video). So basically, everything is drawn in 2D, but the 2D plane is then "rotated in 3D" (or camera is rotated). When ...
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vote
1answer
3k views

Rotation of images in Slick2D

I have have a rotation problem in the Slick2d library, the image is just not rotating (ie I set a rotation but no result is shown). Here is the rotation code: if (input.IsKeyDown(Input.KEY_LEFT)) { ...
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votes
2answers
901 views

What is the difference between Vector2.Transform and this method?

I've been working on some steering behaviors and ran into trouble with my logic for converting points in world space into points in local space. I had this (it's not optimized for multiple points yet, ...
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1answer
442 views

Rotate an existing quaternion around an axis?

I have an existing quaternion (Java Quat4f). I would like to rotate this quaternion around an axis (i.e. 90 degrees around the x axis, 25 degrees around the y axis, 10 degrees around the z axis, 180 ...
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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
363 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 ...
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3answers
614 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 ...
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4answers
828 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 ...
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2answers
2k 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 ...
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2answers
955 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 ...
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votes
1answer
622 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 ...
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2answers
783 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 ...
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2answers
403 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
13k 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
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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
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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
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1answer
378 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
7k 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?
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vote
2answers
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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 ...
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3answers
770 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 ...
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2answers
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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
610 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 ...
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2answers
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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
530 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 ...
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votes
1answer
252 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
622 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 ...
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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 ...
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votes
0answers
367 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] ...
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votes
3answers
493 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
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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
746 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 = ...
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2answers
645 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 ...