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

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1answer
766 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
2k views

Weird rotation problem

I'm creating a simple tank game. No matter what I do, the turret keeps facing the target with it's side. I just can't figure out how to turn it 90 degrees in Y once so it faces it correctly. I've ...
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0answers
55 views

Increment grid by rotation

I'm currently working on a grid for snapping objects side by side. My current script is working fine, but only for game objects which haven't been rotated. Here is an example video of the problem: ...
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0answers
209 views

Quaternion - rotating rigidBody to particular angle over time

Using Bullet Physics. There's a rigid body that is rotated. For some delta-time I need to rotate that body to have rotation of (0, y, 0) - keep the old y value rotation but reset x and z. The ...
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0answers
34 views

Xna 4 Model Rotation with inertia not working as expected with variable updates

I am trying to rotate a model with inertia damping with the keyboard. The code works great with a fixed time step but it doesn't behave the same with a variable update frequency. Update method: ...
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0answers
53 views

How should I model rotation caused by bounce friction? [duplicate]

In my Java2D simulation, I have a disc which, when it bounces off the boundary of a 2D region, begins to rotate, as if it had gotten some spin from the wall. I'm having trouble relating the ...
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4answers
837 views

How to set speed of circular motion

Edit 2 - clarification Just to clarify, the issue I have at the moment is how I specify a time (in seconds) for a complete revolution to occur. My delta is fixed and is 1/ticks per second (1/60). ...
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0answers
1k views

Arcball 3D camera

I have checked multiple threads before posting, but i havent been able to figure this one out. Ok so i have been following this tutorial, but im not using glm, ive been implementing everything up ...
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1answer
1k views

Problem using glm::lookat

I am trying to rotate a sprite so it is always facing a 3D camera. Object GLfloat vertexData[] = { // X Y Z U V 0.0f, 0.8f, 0.0f, 0.5f, 1.0f, -0.8f,-0.8f, 0.0f, ...
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0answers
142 views

Pitch (X-axis) rotation problem [closed]

Situation: From a first person perspective (camera position) I want to be able to grab an object and have it fixed to the center center of the screen while looking up-down (pitch) and looking ...
2
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0answers
660 views

Rotation of viewplatform in Java3D

I have just started with Java3D programming. I thought I had built up some basic intuition about how the scene graph works, but something that should work, does not work. I made a simple program for ...
2
votes
1answer
426 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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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 ...
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vote
1answer
893 views

How to get a point to the left/right of a vector

I have a position vector of a point in space and a quaternion for it's rotation. What i'm trying to calculate is a point too the left and a point to the right. I have the position and ...
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2answers
3k 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 ...
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3answers
395 views

Inverting matrix then decomposing gives different quaternion than decomposing then inverting the quat

I'm getting different signs when I convert a matrix to quaternion and invert that, versus when I invert a matrix and then get the quaternion from it: Quaternion a = Quaternion.Invert(getRotation(m)); ...
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2answers
1k 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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5answers
2k 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 ...
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1answer
1k views

Scene graph in Unity3D

I was wondering if any scene graph-like mechanism is implemented into Unity3D? For example if I have a GameObject, can I add child cubes to it so when I rotate the parent GameObject, the siblings will ...
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3answers
700 views

Rotation matrix for a 3D vector

I have a direction vector on which I have to apply some rotation to align it to positive z-axis. To use Matrix.CreateRotationX(angle) of XNA, I need the angle for which I'd have to compute cos or tan ...
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2answers
1k views

“Align” a rotation to a direction

Good day all. I have a 3d object with a random rotation. I can express that object's rotation both through a quaternion or through an euler rotation. Then I have a vector3 normal that I get from a ...
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2answers
832 views

Matrix Rotation with three Angles

I want to rotate a form with three given angles fo each of the three axis. But the GLM rotation function takes only one angle and a vector as arguments. How can I convert between both formats?
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1answer
7k views

Rotate to a set degree then stop Unity [closed]

I'm trying to make an object rotate up on the Y axis 90 degrees, then stop. I've got the rotating up bit working fine, it's getting it to stop once it hits 90. Some of the things I've tried include ...
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vote
1answer
34 views

Why is the camera tilting around the z axis when I only specified x and y?

My goal is to program a camera to point towards the mouse cursor. I attached the following script to the Main Camera. using UnityEngine; using System.Collections; public class CameraController : ...
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1answer
176 views

How to rotate object not from it's center point but from it's another point?

I am new in unity and I am developing a game where I want to rotate my object I try this code for it. if(Input.GetMouseButton(0)){ if(Input.GetMouseButtonDown(0)){ ...
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2answers
2k views

LibGdx sprite rotation vs Box2D physics rotation problem

LibGdx sprite rotation vs Box2D physics rotation problem Tearing my hair out on this one. I am an experienced software developer, but very new to LibGdx and Box2D development. I am writing a game ...
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1answer
2k views

Movement and rotation of bodies in top down game

We are developing a 2D top down game with libgdx using the included box2d as physics engine. We don't want our bodies to accelerate but to instantly move with the wanted velocity. The bodies are ...
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1answer
1k views

Rotate triangle so that its tip points in the direction of the point on the screen that we last touched

OpenGL ES - Android. Hello all, I am unable to rotate the triangle accordingly in such a way that its tip always points to my finger. What i did : Constructed a triangle in by GL.GL_TRIANGLES. Added ...
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1answer
55 views

Rotating a square rendered on a Bitmap

I'm writing a Software Renderer for fun/learning. Basically, it's just a giant array of integers which contain hexadecimal values (representing colour) that are rendered to the screen.... int ...
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2answers
512 views

What torque should I apply in Bullet to maintain a vertical orientation?

I have a RigidBody in Bullet. Each frame, I want to apply torque to correct its orientation toward an upright position (i.e. near-zero pitch and roll). I know its angular velocity and orientation. ...
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vote
2answers
246 views

Detecting collision of two sprites that can rotate [duplicate]

I have a problem with collision detection in a 2D Java game. Normally, what I would do is create a getBounds() method for an object that can collide with other objects. This method would return a new ...
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1answer
277 views

Sprite rotation

I'm using OpenGL and people suggest using glRotate for sprite rotation, but I find that strange. My problem with it is that it rotates the whole matrix, which sort of screws up all my collision ...
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1answer
938 views

Need to translate a Rotation Matrix to Rotation y, x, z OpenGL & Jitter for 3D Game

I am using the Jitter Physics engine which gives a rotation matrix: M11 M12 M13 M21 M22 M23 M21 M32 M33 And I need it so OpenGL can use it for rotation GL.Rotate(xr, 1, 0, 0) GL.Rotate(yr, 0, 1, ...
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1answer
3k views

Rotate an object around a point in Ogre3D [duplicate]

Possible Duplicate: How can I rotate about an arbitrary point in 3D (instead of the origin)? I am new to 3D programming and I have been using Ogre3D lately to get a grasp of it. What I am ...
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1answer
546 views

Detecting pixels in a rotated Texture2D in XNA?

I know things similar to this have been posted, but I'm still trying to find a good solution... I'm drawing Texture2D objects on the ground in my game, and for Mouse-Over or targeting methods, I'm ...
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1answer
542 views

Rotating a cube using jBullet collisions

How would one go about rotating/flipping a cube with the physics of jBullet? Here is my Draw method for my cube object: public void Draw() { // center point posX, posY, posZ float ...
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3answers
1k views

XNA create differences in enemies

I created an enemy class for my game. It works well, except for one dilemma. When I spawn more than one enemy, eventually they begin to "overlap" and look like one enemy. I was wondering if anyone had ...
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2answers
953 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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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 ...
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1answer
68 views

Determine which face of a cube is facing the camera

I have a Cube with a unique color for each face. I made a script where I can swipe and rotate the Cube in increments of 90 degrees in each direction. what's the best way to determine which face of a ...
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1answer
61 views

Why is rotation not applied instantly?

I am working though the Space Shoot tutorial and I have just applied tilt to the player object. One of the things that I have noticed is that the tilt is not applied instantly but instead the player ...
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vote
2answers
200 views

How do I limit the rotation speed of a mouse-following object?

I am trying to make a 2D top-down game where player controls a spaceship. The spaceship (a rocket) is just a sprite following the mouse cursor with a fixed speed and is always pointing toward the ...
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vote
2answers
646 views

Quaternion Rotation - Clockwise or Counter-Clockwise?

when we specify a Quaternion as (axis of rotation, rotation amount), in which 'direction' is the rotation, assuming we are looking down the rotation axis (i.e. camera at the origin, looking along the ...
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vote
3answers
977 views

How to calculate corner marks of a rotated rectangle?

I've got two elements, a 2D point and a rectangular area. The point represents the middle of that area. I also know the width and height of that area. And the area is tilted by 40° relative to the ...
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vote
1answer
315 views

Mouse click movement

I need to make realistic human movement (3D) using mouse click. Get mouse click point using Raycast. Smoothly Slerp to LookRotation. Move transform.forward. Everything works fine, except I have ...
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1answer
886 views

Libgdx Do a fixed rotation for orthographic camera

Im trying to rotate my orthographic camera in the render loop to a fixed angle, but I can only make the camera spin with the code I got: in the create OrthographicCamera camera = new ...
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2answers
404 views

what's wrong with my lookAt and move forward code?

so am still in the process of getting familiar with libGdx and one of the fun things i love to do is to make basics method for reusability on future projects, and for now am stacked on getting a ...
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1answer
217 views

Bullets won't shoot out of barrel in top-down shooter

So I am working on a top down shoot and have been stumped on why my bullets refuse to come out of the barrel of the gun. I know about the rotation equation which is x2 = x * cos(theta) - y * ...
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vote
1answer
372 views

libgdx get rotated sprite coords points

I would like to get the position of each edge of a sprite when he has been rotated. I have no idea how to do it, I made a image to explain it. I would like to get the X and Y position of each Red ...
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vote
1answer
58 views

Find out which way to rotate based on current rotation and final rotation [duplicate]

I have one object that I want to rotate to a certain angle with 'smooth' rotation. I looked up on how to solve that and I came up with this: enter image description here But how do I know in what ...