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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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 = ...
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2answers
262 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 ...
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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
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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
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3answers
594 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 ...
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2answers
569 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
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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 ...
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1answer
143 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 ...
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1answer
468 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 ...
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1answer
419 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 ...
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3answers
837 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, ...
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2answers
326 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 ...
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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 = ...
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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
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1answer
388 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 ...
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3answers
3k 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 ...
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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 ...
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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 ...
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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
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3answers
622 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
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1answer
502 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
243 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 ...
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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
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1answer
462 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
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1answer
447 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
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1answer
4k 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
481 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 ...
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1answer
752 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 ...
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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 ...
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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
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3answers
752 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 ...
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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
841 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 ...
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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
9k 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
502 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 ...
3
votes
1answer
617 views

How do you get an object to orbit around a certain point on a 2d plane?

I had a concept for a game come to me this morning but I can't figure out how I'd go about implementing the movement. The general idea involves the left and right controls causing a sprite to go ...
3
votes
2answers
3k views

HTML5 canvas screen to isometric coordinate conversion

I am trying to create an isometric game using HTML5 canvas, but don't know how to convert HTML5 canvas screen coordinates to isometric coordinates. My code now is: var mouseX = 0; var mouseY = 0; ...
2
votes
1answer
169 views

Integration of homogenous wave

I have a 2D matrix; each of its elements describes a homogenous coordinate in 3D wave (the values of wave coordinates are changed in time). The wave rendering is done with texture. I need to make an ...
6
votes
3answers
4k views

Left-Hand and Right-Hand Coordinate Systems

In Blender and other 3D modeling tools, the coordinate system is right-handed, while in Unity 3D and Orbiter Space Flight Simulator, they are left-handed, why this could happen? Why they don't simply ...
3
votes
1answer
157 views

Coordinate based travel through multi-line path over elapsed time

I have implemented A* Path finding to decide the course of a sprite through multiple waypoints. I have done this for point A to point B locations but am having trouble with multiple waypoints, because ...
1
vote
1answer
306 views

What to do to UV coordinates, when swapping Z/Y coordinates (axis) of the geometry?

In my Maxscript exporter I have the ability to flip the Z/Y axis by simply swapping the Z and Y co-ordinates. When swapping the axis this way, what is the correct thing to do to the UV coordinates? ...
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1answer
1k views

Isometric screen to 3D world coordinates efficiently

Been having a difficult time transforming 2D screen coordinates to 3D isometric space. This is the situation where I am working in 3D but I have an orthographic camera. Then my camera is positioned at ...
2
votes
1answer
3k views

Converting 3D coordinates to 2D and back?

I'm wondering if there is a simple way to convert 3D coordinates to 2D coordinates. Also, if it's possible, to convert in the reverse direction. I'm using OpenGL(GLUT) in my C++ project. I am also ...
5
votes
4answers
289 views

detecting the coordinates where a bullet hits a mesh

I have a lot of complex objects in a scene and I'm looking for an efficient way to find which object a fired bullet hits, and to find the hit coordinates. It would be best if there was a lightweight ...
1
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1answer
172 views

Is there a memory read/write or performance difference when applying affine transformations on a movieclip rather basic elementary math

I am using Actionscript 3.0 to make games and I fall into the category of programmers who use ball.x+=5; ball.y+=5; in order to move a ball by 5 pixels horizontally and vertically. Well, now i seem ...