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

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2D Rotation Transform Matrix Issues

I'm stuck on my computer graphics class homework. I'm sorry if this is not right place to ask. I think this is closest thing to computer graphics. My assignment is to create basic 2D colored ...
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477 views

Is this Rotation Matrix correct?

I'm having heavly troubles with setting up a View Matrix and a Projection Matrix. It simply doesnt work. So I think my problem is related to my rotationMatrix function. I'm using this tutorial to ...
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2answers
539 views

How do I apply 2 rotations about different points to a single primitive using OpenGL

I'm working on a 2D top-down shooter game that has a rotation feature like Realm Of The Mad God such that if you press e the camera rotates around the character in a clockwise direction and q rotates ...
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1answer
276 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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110 views

Rotating a scene around a fixed axis

I am looking for a way to move my scene so that when I translate forward/back/left right it moves directly up/down/left/right on the screen. Currently it does do that until I rotate (by anything ...
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2answers
141 views

Strange quaternion rotation

I was implementing some quaternion rotations in too my infant 3d game engine and the rotations were really strange? Excuses my cluelessness. Anyways this is what I have: static XMVECTOR ...
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156 views

Quaternion Rotation Help

So I'm making a little engine with DirectX 11 and C++. (Some other help from other API's as well) DirectX has this function XMMatrixRotationQuaternion(XMVECTOR quaternion). I know nothing about this ...
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2answers
114 views

How can I make an object move in four directions relative to its rotation?

I want to make a game object move in directions relative to the direction is facing. That is, If the user presses the "W" key the object goes "forward" if its presses "D" the object goes to its left. ...
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110 views

X, Y, Z rotation around camera

I'm making a 3d orthogonal-projected, game using painters' algorithm in java. I'm able to rotate the objects with incremental rotations (e.g. rotate all objects 10 degrees) using affine ...
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1answer
109 views

From 3d rotation, snap to nearest 90 directions

I have a 4x4 transformation matrix, made only from successive rotations and translations, and I'd like to "snap" my object to the "nearest" of the 24 orthogonal (multiples of 90 degree) rotations. ...
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1answer
148 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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21 views

How can I control the “speed” of a func_rotating object via Squirrel scripting in Portal 2?

I wish there was a better place to ask this, but I've ran out of ideas (after googling and finding nothing even close to what I'm looking for). I basically have this rotating platform. At the ...
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1answer
1k views

How can I make my player move in the direction the camera faces?

I have a 3rd person camera which can rotate around the player. My problem is that wherever camera is facing, players forward is always the same direction. For example when camera is facing the right ...
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1answer
777 views

How To Approach 360 Degree Snake

I've recently gotten into XNA and must say I love it. As sort of a hello world game I decided to create the classic game "Snake". The 90 degree version was very simple and easy to implement. But as I ...
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1answer
2k views

Unity 2D, C# - Make object move diagonally by a certain angle?

I have a sprite object which I want to move in 8 directions. Left, Right, Up, Down, Left top, Right top, Left down, Right down. The view is 2D with a isometric projection. The difficulties I am ...
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65 views

Camera rotation issue Libgdx

I have a OrthographicCamera and I want to rotate 90° it, but when I rotate it seems to be shifted more to the right. Before rotation: http://postimg.org/image/tc9jpq9zr/ After ...
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1answer
52 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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1answer
828 views

Box2D body rotation with setTransform

I' having a problem rotating a body with setTransform(), The body has multiple sensors that should rotate with the player. The rotation works but it rotates around the bodys local 0,0 position instead ...
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1answer
304 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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4answers
387 views

Accurate sprite rotation with mouse movement

I am using the current mouse position to aim the player sprite, but I am not getting the best results. It will often by off by a noticeable amount, or even a complete ~180 off if I go from one side, ...
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2answers
380 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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1answer
1k views

Simultaneously translating and rotating sprite in Unity

I have a 2D object (a PNG file I dragged onto the screen) which is a circle I would like to move left and right when the correct side of the screen is touched and have it rotate in the respective ...
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1answer
75 views

Gradually reduce speed

Basically I am working on following application of android version Party Games: Drinking Wheel For this I want to rotate wheel and want to stop wheel at specific point. But I want this with gradually ...
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1answer
126 views

How can I trigger an event each time the rotation of my rigidbody2D is at a given value?

I would like to trigger an event each time my rigidbody2D is at a particular value. The event should only be triggered once for each given value per complete object revolution. Initial attempts at ...
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1answer
108 views

Rotating a vector around a vector in 3D space

I am trying to rotate a moon around a planet (the planet is also rotating around an axis) but I am having trouble doing so. I tried to make the model move through space like so: @Override public ...
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2answers
144 views

Why do we say things are rotated around the z-axis in a space graph?

I've embarked on a journey of game development. I need to learn lots of 3D terminology, since I want to make 3D games. I learned that X is to the right, Y is up, and Z is towards you. Then why when a ...
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75 views

PhysX - Revolute joint around unit vector

I'm using a right-handed coordinate system with (0,0,-1) = forward, (1,0,0) = right and (0,1,0) = up. PhysX version is 3.3.0. I have a unit vector which represents the axis around which my actor is ...
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1answer
28 views

Error in plane transformation

I have a bunch of coplanar points, who sit on plane P. I want to translate the plane to Q with the points upon. Here is what I do: I take three points from P, say a, b, c. Their centroid is denoted ...
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2answers
110 views

Do I need to store a generic rotation point/radius for rotating around a point other than the origin for object transforms?

I'm having trouble implementing a non-origin point rotation. I have a class Transform that stores each component separately in three 3D vectors for position, scale, and rotation. This is fine for ...
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1answer
180 views

Rotation with XMMatrix to Rotation with XMFLOAT3

I'm rotating a Direction Light around a fixed object, so the light only contains a XMFLOAT3 to determine it's direction that it is facing. I have another object rotation using the variable Rotation ...
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2answers
277 views

How can I simplify this code to compute the shortest rotation between two angles?

The following code will find the shortest rotation (in radians) (from pi to -pi) that I need to apply to from to leave me with to. Scalar rotationBetween(Scalar from, Scalar to) { Scalar fromMod ...
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0answers
32 views

Unity 2D angular velocity center [duplicate]

I try to add angular velocity to my GameObject with this command: rigidbody2D.angularVelocity = Random.value * tumble; All works, but I want center of velocity be in the center of my rigidbody, but ...
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74 views

Camera movement in Super Hexagon

I do realize there is no camera in OpenGL ES 2, but from my understanding you can simulate one using view and projection matrices. I'm using Android, by the way. Here's a video of the game, in case ...
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1answer
77 views

3d rotation of a Gunner unit to shoot the target

I'm developing a scenario to shoot incoming targets by a specific gunner unit, however I'm confused to actual logic of shooting an object with a gun. I'm working in 3D environment. I'v target's ...
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2answers
171 views

What are “local” and “global” rotations?

Each node in jME3 has local and global rotations, which can be expressed in quaternions. What are they? Documentation has no clues, about in which state rotations are zero?
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1answer
115 views

XNA 3D cube rotation problem

I am new to game programming and still trying to clear up my basics. I am stuck with a problem and unable to resolve on my own knowledge. I am trying to rotate a 3d cube in MonoGame (Similar to XNA) ...
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1answer
683 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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3answers
572 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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1answer
665 views

Repelling a rigidbody in the direction an object is rotating

Working in Unity, I have a game object which I rotate each frame, like so: void Update() { transform.Rotate(new Vector3(0, 1, 0) * speed * Time.deltaTime); } However, I'm running into problems ...
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1answer
654 views

libgdx rotation (animation, arrays) issues and help needed

well i am a noob at java and libgdx. i got the homing bullet working with the help of someone. now i am smashing my head as to how i can make it rotate so it faces the ball (which is the main ...
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2answers
312 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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3answers
528 views

How to rotate a set of points on z = 0 plane in 3-D, preserving pairwise distances?

I have a set of points double n[] on the plane z = 0. And I have another set of points double[] m on the plane ax + by + cz + d = 0. Length of n is equal to length of m. Also, euclidean distance ...
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0answers
40 views

How to rotate a trigger actor in UDK?

Working on a project and I need a trigger actor to detect a custom projectile type I've made. I would use a KActor with a TakeDamage event, but KActors despawn my projectiles. The issue is that I ...
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1answer
303 views

Can I have a fixed-angle sprite with a non-fixed-angle CircleCollider2D?

In Unity2D, can I have a fixed-angle sprite with a non-fixed-angle CircleCollider2D? I would like to move my character using the circle physics (without fixed-angle), but display him always as if he ...
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2answers
121 views

How can I find the difference between rotations represented as angles in [0, 360]?

What is the easiest way to find the difference between two 2D rotations/directions? I want to test if one rotation is within 10° of another. I would just subtract, but there are some problems ...
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39 views

Why the rotation matrix of X(θ1)Y(θ2)Z(θ3) can be viewed as extrinsic rotation of order ZYX and intrinsic order of XYZ?

As title, from wiki and OpenGL red book(7e) I found the expression v' = R_x * R_y * R_z * v can be viewed as Rotate vector v about local x axis, and y axis, finally z axis. Rotate vector v about ...
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1answer
2k views

Rotate image around a specified origin

I'm trying to rotate my Turret.png (small Gunhead with a laser in front) towards the mouses location on the screen. I tried just using my method for rotating projectiles towards the next step on their ...
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1answer
202 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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3answers
650 views

How do I disassemble a 3x3 transformation matrix into rotation and scaling matrices?

I have a transformation matrix that rotates and scales. Is there any easy way to disassemble it into the original rotation and scaling matrices? For instance: M = R * S; // I need f and h such that ...
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0answers
192 views

Unity crashes completely when I rotate my objects [closed]

I've started my first tiny Unity project and after 20 minutes I run into a brick wall. My goal was to create a Android 2D game with falling polygons, that you have to click and they disappear. ...