# Tagged Questions

The directional facing of an entity in the game space.

5k views

### Why is Y up in many Games?

I learned at school that the z-axis is up. It is the same in modeling software like Blender. However in many games the y-axis is up. What is reason?
4k views

### X, Y, Z coordinate standards?

I'm pretty new to 3D development of any kind, nonetheless games. As I read through tutorials and examples, I find that the X/Y/Z coordinates seem a bit backwards than my first guess. I had imagined ...
616 views

### Changing orientation by applying torques

Suppose you've got an object floating freely in space. You have a vector you want this object to point towards, and a vector representing the direction it's currently facing. From these two, you can ...
2k 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 ...
4k views

### How is the gimbal locked problem solved using accumulative matrix transformations

I am reading the online "Learning Modern 3D Graphics Programming" book by Jason L. McKesson As of now, I am up to the gimbal lock problem and how to solve it using quaternions. However right here, ...
2k views

### Quaternion Look At with Up vector

I have implemented a "look at" method for my screen elements and it almost works how I want it to work. The ScreenElement class uses a R3 Vector and a Quaternion to determine the position and ...
2k views

### How to calculate left/right oriented angle between two 2D vectors? [duplicate]

I would like to calculate angle between two 2D vectors. Here's a picture of what I'm trying to achieve: I have an obstacle line segment AB and incoming moving PC. If I'm coming from one side C¹D¹ ...
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### How can I reorient the axes of an object?

I spent some time in Unity yesterday trying to fire a sphere from a horizontal cylinder (like a ball from a cannon). I was using Vector3.forward, but the sphere kept coming out the top of the cylinder ...
101 views

### Finding the monitors orientation in XNA for Windows

Just to be clear this is not for Windows Phone 7. =) I've got some interesting requirements for a project and I'm having trouble trying to find the information I need. I have two monitors. The ...
191 views

### How to make an object stay relative to another object

In the following example there is a guy and a boat. They have both a position, orientation and velocity. The guy is standing on the shore and would like to board. He changes his position so he is ...
222 views

### Follow point of interest by applying torque

Given a body with an orientation angle and a point of interest or targetAngle, is there an elegant solution for keeping the body oriented towards the point of interest by applying torque or impulses? ...
248 views

### How to map absolute Joystick position to object rotation?

In my (Ogre) 3d scene I have an object that should be rotated locally based on Joystick input. I have a Joystick with min/max values of [-32767, 32767] on both X and Y axes. When the Joystick is in ...
253 views

### How do I determine a device's default orientation?

I am developing a game with accelerometer controls. This works well on all the mobile phones I've tested it on. However, when testing on a tablet, the y and x axes are reversed, presumably because the ...
942 views

### Unity Android Orientation Bug in Auto Rotate

I am currently looking for a workaround, or fix, for a Unity bug. I want to be able to auto-rotate my game, while respecting the Android system settings. Currently, if you set your Unity Orientation ...
475 views

### Setting Orientation of Character in Bullet/Ogre [closed]

I've been suffering from an issue regarding the implementation of orienting characters in a game I'm implementing using Ogre3D and Bullet physics. What I have: A Direction Vector that the character ...
551 views

### How can I use orientation to compute position in Windows Phone 7? [closed]

I'm using the motion API and I'm trying to figure out a control scheme for the game I'm currently developing. What I'm trying to achive is for an orienation of the device to correlate directly to a ...
3k views

### convert orientation vec3 to a rotation matrix

I've got a normalized vec3 that represents an orientation. Each frame of animation, an object's orientation changes slightly, so I add a delta vector to the orientation vector and then normalize to ...
103 views

### How can I min-max quaternions?

What I'm doing In my engine, I'm trying to implement a camera that will follow a target object, such as a player. I wanted to avoid just simply using the inverse of the target's transformation, ...
387 views

### How do I fix my planet-facing camera?

Summary I'm having trouble implementing a camera controller suitable for first person use around a planet. The camera needs to be oriented correctly according to gravity (vector from camera ...
51 views

### Vector magnitude in orientation

First, a quick overview of my problem: I have a game entity which has a quaternion to represent its rotation/orientation. It also has a 3D vector in world space for its linear velocity. From the ...
61 views

### Torch fire always up regardless of handle direction

I have a prefab from some asset pulled into our project. It is a simple torch.. handle and a particle system for the fire. Works perfect if mounted on a wall and torch angle adjusted no problem. ...
87 views

### Turn the front wheels of a car according to the car's bezier path

I have a 3D car which follows a predefined 3D Bezier path. I want the car's front wheels' rotation to match the car's changing direction. I had the idea to match the wheel's orientation to the ...
620 views

### Change game from portrait to landscape dynamically

I have multiple classes that implement Screen. I want to, say, have the Main Menu screen portrait, then the Play Screen landscape. Is there anyway of changing the orientation dynamically? I thought ...
120 views

### How to calculate a quaternion rotation between 2 vectors with a specific final up vector?

I know you can calculate the quaternion rotation between 2 vectors with something like this after all the optimizations: quat quat::fromtwovectors(vec3 u, vec3 v) { vec3 w = cross(u, v); ...
282 views

### Finding relative x and y value on a sprite [Gamemaker]

I'm having a little conundrum that may just result from a lack of knowledge of Gamemaker's functionality. I've attached two images to aid explanation. I have a sprite of a turret (with a gun ...
187 views

### 2D space combat - turn based, orientation / facing [closed]

Another rewrite - By they way thanks, because your former critics made me think of this.: I am currently building a tactical turn based combat game in space. Movement is (now) on a grid. The player ...
147 views

### How can I support both multiple resolutions and multiple orientations in a game?

I am writing a mobile Android and iOS game. This game is similar to Doodle Jump, but without scrolling. In my game I display a background image that should cover the entire screen. On top of that I ...
31 views

### Position camera in opengl

I have a camera with a 3D vector that represent the position and a quaternion that represent the camera orientation. I'm trying to rotate and orientate the camera correctly, but I can't. I know that ...
54 views

### Google Games Services Display Orientation

I'm developing a game using LibGDX and I'm using BaseGameUtils to implement Play Games Services in it. It's working very well. But my game is in landscape mode, so when I call leaderboard or ...