# Tagged Questions

Numeric representation of the location of an entity in the game space. There are multiple forms of coordinate systems to cater to a variety of methods to map position.

114 views

### How are CSS and WebGL coordinates related? [closed]

I'd like to build a simple framework which rendering combines web page DOM elements with WebGL, such that they're manipulable in the same coordinate space. How does the plain CSS coordinate system ...
157 views

### Pre- or post-multiplication for rotation between coordinate frames

I have three 3D coordinate frames: O, A and B, as shown below. I want to know the rotation matrix RAB between A and B, that is the rotation that is required, with respect to the frame A, to move ...
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### Rotating between two coordinate frames

I have two coordinate frames, A and B. I want to create the rotation matrix RAB which takes you from A to B. A is a right-handed system, and B is a left-handed system. Furthermore, after moving from a ...
169 views

### How to get a position from a radial distance and angles?

I have a radius and the 2 angles for northSouth and eastWest rotations in degrees. I need a Spherical position or a cartesian position (I have code translate one to the other) Where a position is ...
77 views

### Transformations between coordinate systems

In a graphics engine, I have three three-dimensional orthogonal coordinate systems, O, A and B. A and B are the result of two different transformations from O. I now want to calculate the ...
372 views

### How can I compute which chunk a coordinate is in?

I am working on a video game. Everything (terrain, entities, particles) is stored in 100 by 100 chunks. Here is the array structure for the chunks: public static final int chunkSize = 100; public ...
71 views

### Collision detection in JavaScript Canvas game - Issue with 'if' statements [duplicate]

I am currently developing a simple browser-based game and seem to be on the cusp of collision detection that doesn't just return the player to where they were before, but actually will slide them ...
130 views

### “aim at” in 3D space algorithm

I'd to calculate the cartesian rotate values of "aiming" one point at another in 3D space. For example, assuming rotation order of XYZ: Point A is at [0, 0, 0] Point B is at [2, 2, 0] If point A was ...
187 views

### Mouse position to grid position not working

I have a function which converts my mouse position to grid position in the game but it is not working properly... its slightly off. I have two functions - one which converts from grid to screen ...
399 views

### How to put the game object to the upper left corner of the screen in Unity and make it visible entirely on all screens of mobile devices

I have game object which displays health indicator in my 2d video game in Unity. This gameobject contains a lot of sprites and i put it into left/top corner of the screen. In my game editor it is ...
266 views

### Bounding Box not rotating based on draw rotation (Java)

In the process of developing a 2D game and am having some issues with translating coordinates on rotation. The object being rotated is a sword that is attached to the player. The player currently ...
353 views

### How do I convert from rectangular to spherical coordinates?

This seems like a fairly basic and common problem. Is there a builtin way to achieve it or do I have to write the algorithm on my own? If I do, how should it work?
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### OpenGL: What's the best way to convert a screen coordinate to a world coordinate? [duplicate]

For example, suppose I'm building a first-person shooter and the player pulls the trigger. I want to convert the screen coordinate (x, y) into a world coordinate (x, y, z) to know what they've hit. I'...
820 views

### How do I get the mouse coordinates relative to my whole scene with Monogame? [duplicate]

I am making a topdown isometric real time game using Monogame. I know how to get the mouse position for my camera view. How do I get the mouse coordinates relative to the entire scene? My game's ...
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### How to change the position of a circle in pygame in three stages

I will try to explain it as well as I can excuse me if I'll fail. I have the following simple game situation: I know the coordinates of each point. So each of the green points try to hit the blue ...
118 views

### Colision detection of disc (Maximum Material Condition aka “Flatness”)

I have a 3D-laser scanner which gives me a series of points of a real-world object. The points are related by a common origin. I know I can derive the equation of a plane from 3 points and that the "...
7k views

### Why is the origin in computer graphics coordinates at the top left?

From what I've seen almost all things use coordinates where (0, 0) is at the top left and the positive Y-axis goes in the downwards direction of your screen. Why is it like this? Why not the ...
319 views

### Mouse coordinate conversion Libgdx

I have a camera: //Map is a my object that wrapper of TiledMap class In the create method: this.renderer=new OrthogonalTiledMapRenderer(this.map.getMap(); this.camera=new OrthographicCamera(); ...
160 views

### Screen coordinates to isometric coordinates?

I know this has been discussed here before, but I couldn't find an easy solution for my particular problem. I have a tile system and I'd like to convert screen coordinates into isometric tile ...
260 views

### Coordinates issue vertical scroll Libgdx

I'm going crazy with this problem. I'll explain: I have a camera that falls down (flowing along the y-axis) which displays a TiledMap and declare the whole in this way: In the create method: map=...
484 views

### Libgdx 2D Game, Random generated World of random size, how to get mouse coordinates? [closed]

I'm a noob and English is not my mothertongue, so please bear with me! I'm generating a map for a Sidescroller out of a 2D-array. That is, the array holds different values and I create blocks based ...
2k views

### How do I translate a spherical coordinate to a Cartesian one?

Could someone point me in the right direction as to how this might be achieved? 3D math / geometry often throws me. I'm looking for something like this (ideally in C#): public Vector3 ...
763 views

### Why AnchorPoint doesn't affect `CCLayer` Positioning?

I think there is a difference between CCLayer and CCNode behavior when I change their AnchorPoint. I will describe what I mean and please somebody explain it ? Scenario: I start with CCNode CCNode *...
7k views

### How do I convert from the global coordinate space to a local space?

Given an entity named EntityA, I want to define a local coordinate space, where the position of EntityA is the origin, its heading vector is the X axis, and the normal of the heading vector is the Y ...
5k views

### Convert Screen coords to World Coords LIBGDX

I'm working on a tile based platformer game in libgdx. I'm having trouble getting the actual touch input coordinates when the aspect ratio of device is different from the virtual fixed aspect ratio ...
214 views

### How do I convert screen coordinates to between -1 and 1?

I'm writing a function that allows me to click on my tiles. The origin for my tiles is the center, however, the mouse's origin is the top left. I need a way to transform my mouse coordinates into my ...
191 views

### Why are my 2D world click-positions offset after camera movement?

I'm writing a 2D game engine. I need to add a camera to my world that can zoom in and out as well as move away from its initial position at (0,0) at the center of the world. The main issue can be ...
754 views

### How to project spherical coordinates to canvas

I have objects with coordinates in a spherical coordinate system (altitude alt and azmiuth az). I want to project those to my canvas with a given size (128 x 128 pixels²) and resolution (about 6 px/°)....
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### How can I read the color of a specific pixel in XNA?

I want a way to find out if, for example, the pixel at Vector2(2, 5) on the game window is color Color.Red, or some other color or set of coordinates. How can I do this?
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### Could you explain this calculation of tiling and offset?

I don't understand why we add +colNumber when we calculate the offset = Vector2 ((uIndex+colNumber) * size.x, which gives us x=3 for the index 13, which is the square located at the coordinates x:1, y:...
164 views

### Storing rigid body collision shapes in local or world coordinates

I'm writing the beginnings of a lightweight 2d rigid body engine (in javascript, as a hobby project), and i'm debating whether to store collision shapes in local or in (updated as needed) world ...
4k views

### How to match user click and the sprite object position in libGDX framework

I am using libGDX Java framework for developing a practice game in Eclipse. My game is in landscape mode and I am using sprite image for game assets. Actually I am trying to follow the Kilobolt ...
2k views

### What are the advantages/disadvantages of using a polar coordinate system in a video game? [closed]

Would it ever be a good idea to represent an object's position as a magnitude at some angle relative to a reference point, instead of the typical x, y, z coordinates? What sort of effect would it ...
320 views

### Mismatch cordinate system of unity and android

I am new to unity3d, Right now i am adding a cube as game object with coordinate 0,0,0 But when i run it on android device Iam facing 2 problem a) Coordinate system of unity3d are different from ...
304 views

### How do I flip upside down fonts in FTGL [closed]

I just use FTGL to use it in my app. I want to use the version FTBufferFont to render font but it renders in the wrong way. The font(texture?buffer?) is flipped in the wrong axis. I want to use ...
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### How do I scale and rotate around different points in Libgdx? [duplicate]

I'm using a SpriteBatcher to rotate and scale a TextureRegion in libGDX. I'd like to rotate the texture around an origin outside of the region, but have the texture scaled around the region's center. ...
288 views

### Float-based screen coordinates, higher mouse precision

I wrote 2 weeks ago about problem with motion blur in my engine. When camera moves using keyboard, motion blur is smooth. But when I rotate camera using mouse motion blur is stepping (not sure if I ...
1k views

### Texture coordinates for a 3D box

I have a box model in my DirectX application, stored as 8 vertices: MyVertex vertices[] = { { DirectX::XMFLOAT3( - 1.0f, + 1.0f, - 1.0f ), /*,tex coord...*/}, //0 { DirectX::XMFLOAT3( + 1....
51 views

### drawing line using angle

code below make enemy move towards player. //Calculate Distance formula double xDiff = player.x - enemy.x; double yDiff = player.y - enemy.y; double dist = Math.sqrt(xDiff * xDiff + ...
365 views

### isometric coordinates issue: (0,0) and (5,5) are flipped?

I am having an issue with the isometric coordinates. When I enter the coordinates (5,5), the character should be at the bottom corner of the tile, but it is at the top corner, (5,5) and (0,0) look ...
262 views

### What is the purpose of inertial space and what are its uses?

I'm currently reading about left-handed and right-handed coordinate systems when working with 3D and it's all very fascinating. These systems are made up of world space, object space, and inertial ...
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### Is it bad-practice using left-handed coordinate system in OpenGL eye-space?

In the engine I am currently programming I want to use a left-handed coordinate system for eye-space instead of the glFrustum standard right-handed one. Is that in anyway considered bad practice?
4k views

### Spherical coordinate from cartesian coordinate

I am implementing a type for Ogre 3D rendering engine to provide spherical coordinates. So far everything is working fine, until I try to build spherical coordinates from a cartesian vector. Here is ...
183 views

### What's the rationale for different coordinates systems?

Could someone explain to me why Blender and other 3D modeling apps switch axes? If I export model with Blender, then exporters do following things for the same model: The 3DS format applies this ...
140 views

### How can I solve for the game's world coordinates?

I've used 3DReaperDX to get a obj file, the header information are shown as follows: #AR=2.00606, FOV=45.09583(height), Xscale:0.83290, Yscale:0.41519, Zscale:1.0 #************************************...
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### Need to know the origin and coordinates for 2d texture and 2d/3d vertices in webgl

Long story short, I know my coordinates are off and I believe my indices might be off. I'm trying to render a simple 2d rectangle with a texture in webgl here's the code I have for the vbo/ibo: ...
177 views

### How can I plot points and generate a list of coordinates?

Is there a program that lets me draw, a la pixel art, a map, and give me a list of coordinates and their corresponding colors? For example, I'd like to use a point and click interface to draw this ...
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### What does “Poser-like” mean?

The Wavefront OBJ exporter of 3DSMax says it can flip YZ axis. Claiming this is "Poser-like". What does this mean? And what is the exact transformation if we decide to flip? Is it simply this? x =&...