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.

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9
votes
4answers
4k views

Staggered Isometric Map: Calculate map coordinates for point on screen

I know there are already a lot of resources about this, but I haven't found one that matches my coordinate system and I'm having massive trouble adjusting any of those solutions to my needs. What I ...
0
votes
1answer
297 views

Curiosity on any Smartphones that Run on Android 2.3.3 with Different Screen Reoslution

I have a question regarding about any smartphones that run only in Android 2.3.3. Is the size of screen or the screen resolution is always HVGA or does it have capable of running this OS (Android ...
2
votes
1answer
227 views

Coordinate spaces and transformation matrices

I'm trying to get an object from object space, into projected space using these intermediate matrices: The first matrix (I) is the one that transforms from object space into inertial space, but since ...
1
vote
1answer
93 views

XNA 3D coordinates seem off

I'm going through a book, and the example it gave me seems like is should work, but when I try and implement it, it falls short. My Camera class takes three vectors in to generate View and Projection ...
1
vote
1answer
358 views

Precise Touch Screen Dragging Issue: Trouble Aligning with the Finger due to Different Screen Resolution

Please, I need your help. I'm trying to make a game that will drag-n-drop a sprite/image while my finger follows precisely with the image without being offset. When I'm trying on a 900x1280 (in X ...
4
votes
1answer
1k views

Spherical to Cartesian Coordinates

Well I'm reading the Frank's Luna DirectX10 book and, while I'm trying to understand the first demo, I found something that's not very clear at least for me. In the updateScene method, when I press A, ...
13
votes
1answer
553 views

Orthographic unit translation mismatch on grid (e.g. 64 pixels translates incorrectly)

I am looking for some insight into a small problem with unit translations on a grid. Update and Solved I solved my own issue. See below for details. Everything in this part of the post turned out to ...
3
votes
1answer
2k views

Convert rotation from Right handed System to left handed

I have Euler angles from a right handed system that I am trying to convert to a left handed system. All the information that I have read online says that to convert it simply multiply the axis and ...
4
votes
2answers
1k views

Get world coordinate under mouse (at a ground plane for Warcraft 3 like movement)

I want to let a unit follow the mouse like in any RTS (Warcraft 3, Starcraft, ...). For that I have a "ground plane" which is defined through 2 vectors, the X and Z axis. Now I need to get the world ...
4
votes
1answer
593 views

Isometric Screen View to World View

I am having trouble working out the math to transform the screen coordinates to the Grid coordinates. The code below is how far I have got but it is totally wrong any help or resources to fix this ...
1
vote
1answer
3k views

Converting world space coordinate to screen space coordinate and getting incorrect range of values

I'm attempting to convert from world space coordinates to screen space coordinates. I have the following code to transform my object position Vector3 screenSpacePoint = ...
0
votes
2answers
266 views

get coordinates of origin of coordinate system in second coordinate system by knowin matrices of one point in bith systems

Situation, two coordinate systems A, B. origins Oa, Ob. I have one point, for which i know modelview matrix (translatoin/orientation) in both systems. And what i need to get is modelview matrix of Ob ...
4
votes
3answers
5k views

OpenGL ES and Screen Coordinates

Is there anyway I can make OpenGL ES 2.0 to accept coordinates (for Vextex for example) in int meaning the pixels instead of the default float system? Also how can I set the point (0,0) to be at the ...
5
votes
2answers
1k views

Draw a 3D object at specific coordinates on the screen

I'm creating an application which allows the user to manipulate 3D models. I would like to draw 3 axis representing the world coordinate system in 3D in order to give the user an idea where he is. ...
4
votes
3answers
610 views

Convert point to its barymetric coordinates

I'm making a 2.5D game engine (in JavaScript) and I'm trying to get it to detect whether a block is under the cursor. This would be a simple task were it restricted to single-level isometric ...
0
votes
2answers
590 views

Screen coordinates to a multilevel isometric world

I have an isometric world that has stuff on multiple levels, i.e. it has an XYZ coordinate system, and tiles can be stacked on each other, accumulating screen Y offset as they go. I currently have an ...
8
votes
4answers
4k views

How do I convert between two different 2D coordinate systems?

I'm trying to convert a coordinate from one coordinate system to another, so that I can draw it on an image. Basically the destination coordinate system is as follows: X range: 0 to 1066 Y range: 0 ...
0
votes
1answer
147 views

How should I position and move objects in my 3D world in relation to terrain

I'm drawing a heightfield as a piece of 3D terrain using the fairly 'dumb' method of drawing triangles, like everyone does when learning this sort of thing. There's no fancy LOD, scenegraphs or other ...
0
votes
1answer
503 views

How to get xy coordinates along a given path

Say i have two points (x,y), (0,0) and (10,10). Now i wan´t to get coordinates along the line by stepping through values of x and y. I thought i solved it with the following functions: fy = startY ...
2
votes
1answer
427 views

Detect if square in grid is within a diamond shape

So I have a game in which basically everything is a square inside a big grid. It's easy to check if a square is inside a box whose center is another square: *** x *o* --> x is not in o's ...
2
votes
3answers
850 views

XNA texture stretching at extreme coordinates

I was toying around with infinitely scrolling 2D textures using the XNA framework and came across a rather strange observation. Using the basic draw code: spriteBatch.Begin(SpriteSortMode.Deferred, ...
2
votes
2answers
335 views

how to transform child elements position into a world position

I'm making a 2d space game in Javascript with canvas. In this game there's a bunch of spaceships, positioned in world space, with turrets, positioned relative to their parent ships. These objects also ...
2
votes
3answers
1k views

Isometric to screen, screen to isometric for irregular projection

I have isometric assets that unfortunately can't change and need to work out the projection for those. Here is how a tile looks like: The tile image width/height ratio is 0.(6) (height/widht = ...
-1
votes
1answer
170 views

Find a Rectangle by coordinates - XNA

I have 2 coordinates (X,Y). I have also a 10x10 array. By these coordinates I have to find the rectangle in which is my pointer at the moment. How could I handle it?
4
votes
1answer
401 views

Translation from one coordinate system to another having Z-offset issues

I'm using ARToolkit to do an augmented reality application, but my problem is really with the 3D coordinates. In this application, I use my webcam to generate the scene. I have two markers (printed ...
7
votes
3answers
4k views

2D isometric: screen to tile coordinates

I'm writing an isometric 2D game and I'm having difficulty figuring precisely on which tile the cursor is. Here's a drawing: where xs and ys are screen coordinates (pixels), xt and yt are tile ...
3
votes
4answers
4k views

Java Slick2d - How to translate mouse coordinates to world coordinates

I am translating in my main class render. How do I get the mouse position where my mouse actually is after I scroll the screen public void render(GameContainer gc, Graphics g) throws SlickException ...
1
vote
1answer
146 views

Map displacement transformation to texture space?

I am trying to displace geometry in object space without giving the appearance of texture warping. My idea is to displace the UV lookup by a relative amount to the geometry displacement. Any ...
0
votes
4answers
4k views

XNA spritebatch drawing to the centre of screen

I have bit of a silly problem. Is is possible to use SpriteBatch.Draw() method to draw to the centre of screen using coords from the beginning of window (So resolution 800x600 would use 400;300) ...
3
votes
3answers
647 views

The ship “shudders” in scrolling Asteroids

In my Asteroids game the user can scroll through space. When scrolling, the ship is drawn in the centre of the window. I use interpolation. I scroll the window uing glOrtho, centering it around the ...
3
votes
1answer
526 views

Does the projection matrix flip winding order in right handed systems?

I am using a right handed coordinate system for my world coordinates (so, positive x goes right, y is up, and z is towards you). However, after projection and the w divide, nomalised device ...
3
votes
2answers
246 views

Real time data retrieval - database vs file system

I'm planning to develop a game in which I want to draw 3d models in real time using some given x,y,z coordinates. The coordinates will be given at an average of 30 coordinates per second. Drawing will ...
3
votes
3answers
5k views

Get points on a line between two points

I'm making a simple space game in JavaScript, but now I've hit a wall regarding vectors. The game view is top-down on a 2d grid. When the user clicks on the grid, the space ship will fly to that ...
2
votes
1answer
483 views

How do you extract a Vector3 positions only from a world matrix in an array of positions (from Kinect)

've just started building a physical camera class for the depth data you get from a Kinect. I have a Vector3 array of [imageWidth, imageHeight] describing the LOCAL positions I get in from the kinect ...
2
votes
1answer
448 views

How to linearly transform vertices for large coordinate systems

Alright, so I'm working on a space game and well, I want it to have a lot of space! So I need a large coordinate system and for my rendering pipeline to not suffer from "vertex jittering" due to ...
5
votes
1answer
5k views

Why is my sprite displayed offset from its Box2D body?

I found out about this using a debug renderer. When the game starts, everything is in order. But when a collision happens, the sprite's rotation is way larger than its body. The sprite and body match ...
2
votes
1answer
487 views

Transformed Pretransformed coordinates?

I am creating a minecraft like terrain engine thing in XNA and C#, and I am trying to create a item/block selector tool. The thing is I would like to have 3D objects on the tool. So I thought for the ...
0
votes
1answer
761 views

Confusion with the texture coordinate system in XNA

I am creating a cow out of primitive shapes, and am using the minecraft cow texture as a placeholder. To create the primitive model I have created a 'model' class and created a sub class 'ModelCow' ...
5
votes
4answers
1k views

How does a wow server handle which player position to set to each nearest players?

I already understood how game developers could create very large game levels, bypassing the floating point precision limit. This was my very first mind boggling question, and I understood it when I ...
3
votes
1answer
2k views

Generating spherical world from heightmapped terrain

I am using a standard heightmapped procedural terrain in my project. However, I want the terrain to appear spherical when the user zooms out. This is an attempt to simulate the appearance of a ...
1
vote
1answer
1k views

Scaling and new coordinates based off screen resolution

I'm trying to deal with different resolutions on Android devices. Say I have a sprite at X,Y and dimensions W,H. I understand how to properly scale the width and heigh dimensions depending on the ...
3
votes
2answers
1k views

Converting from different handedness coordinate systems

I am currently porting a demo from XNA to DirectX which, as I understand it, both have coordinate systems with different handednesses. What are the things I need to bare in mind when converting ...
2
votes
2answers
167 views

Transition Player Position

I'm currently working on a Java MMO with a pretty solid start, but I've come across an issue I need a little help with. I'm working on player positions. Meaning their X/Y on the screen, if the ...
3
votes
3answers
779 views

What are heterogeneous coordinate systems and reasons for using them?

The book I'm following for a computer graphics course only talks about homogeneous coordinate systems. But today, our teacher asked: What are the reasons for using heterogeneous coordinate ...
1
vote
3answers
131 views

Finding which side one point is from another point

I have a simple question I think, if point a is to the right of another point I a dirx to be 1, otherwise -1. Likewise for a diry var, if it's above the other point I want it to be -1 otherwise 1. ...
2
votes
2answers
3k views

gluLookAt vs glTranslate + glRotate and camera transformation matrices

I'm getting my hands dirty in OpenGL and something is bothering me a bit. It's my understanding from reading about the subject that a call to gluLookAt basically multiplies a matrix on the stack that ...
1
vote
2answers
854 views

How do i get the X,Y and Z of the way my unit is facing?

I have the yaw and pitch of my unit at my disposal, I know if I use polar to cartesian conversion I'll get the X and Y of each one of those two, but I need them combined to give me the x,y and z of ...
3
votes
3answers
1k views

Spot the difference game design help

I'm thinking of making a spot the difference game. But immediately I stumbled over a problem. I'm thinking of storing a "difference area" in the form of a x,y coordinate. However, because on a ...
6
votes
1answer
10k views

Blender - exporting .obj with texture coords

I'm writing a game which uses obj files. I created an object in blender and I applied texture without UV coordinates and my question is: how to export this object to obj file, but with texture ...
3
votes
2answers
513 views

Path-finding algorithms for Polar coordinate based maze?

Following on from my question about moving a sprite in a circle, assuming that you have a maze which is shaped like a a set of circles with holes in them and barriers between them. Location of a ...