1
vote
1answer
172 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 ...
1
vote
2answers
216 views

What am I missing? (Converting 2D mouse coords to 3D space)

I'm making a networked game which has a birds-eye view and I'm trying to convert the 2D mouse coordinates into 3D space. Right now I have a perfectly flat grid and it intends to remain perfectly flat, ...
1
vote
0answers
82 views

Rotate view matrix based on touch coordinates

I'm working on an Android game where I need to rotate the camera around the origin based on the user dragging their finger. My view matrix has initial position of sitting on the negative z and facing ...
2
votes
2answers
344 views

Why does handedness matter at all?

I'm really trying to understand this from a mathematical viewpoint. After all, numbers are numbers, the chirality or handedness depends on how one interprets it. Say I've three basis vectors x (1, 0, ...
3
votes
1answer
144 views

Calibration of a 6 DOF tracking device

Setting: In our facility we have a 3D laboratory with 3 large displays (two edge-to-edge on orthogonal walls, one on the ground, also edge-to-edge). Its primary use-case is exploring 3D virtual ...
1
vote
1answer
182 views

SimpleOpenNI: Check if user hand is in specific area on image

Concerning our Microsoft Kinect project, we need some help. We control a robot with our movements tracked by the Kinect sensor. We display the depth image of the Kinect sensor on our screen, so we ...
2
votes
1answer
195 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
90 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 ...
0
votes
2answers
472 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 ...
0
votes
1answer
128 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 ...
4
votes
1answer
316 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 ...
2
votes
2answers
895 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 ...
1
vote
2answers
743 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 ...
6
votes
1answer
7k 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 ...
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 ...
-1
votes
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 ...
5
votes
4answers
271 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
vote
2answers
465 views

Rotating coordinate system

Lets say that you want to rotate simple cube around fixed point in center. Is it possible to use such coordinate system, that you need to use only sine and cosine in order to rotate? I have done ...
1
vote
3answers
516 views

Starting off with coordinate systems [closed]

Where is a good place to start with learning how to program custom coordinate systems in a 3d environment? Are there any good books on he topic of gaming coordinate systems? I would like to build a ...
1
vote
1answer
1k views

Converting to and from local and world 3D coordinate spaces?

I've been following a guide I found here (http://knol.google.com/k/matrices-for-3d-applications-view-transformation) on constructing a matrix that will allow me to 3D coordinates to an object's local ...
5
votes
1answer
472 views

Calculate the Z of a line intersection given the XY coordinates?

I'm intersecting a line in 2D and I calculate the X,Y coordinates of the intersection point. What I need is the Z of the intersection point given the X,Y,Z of the line points, and the X,Y of the ...
1
vote
1answer
302 views

3d environments and managing them on iOS

I would like to start learning 3d game development and currently only develop 2d games. A few basic questions I am interested in are: What is used to create the 3d environments? Are they all done in ...
3
votes
1answer
966 views

Ray-plane intersection to find the Z of the intersecting point

I have a rectangle in 3d space (p1, p2, p3, p4) and when the mouse rolls over it I need to calculate the exact Z of the point on the rect, given the mouse coordinates (x, y). Would a Ray-plane ...
4
votes
1answer
1k views

Obtaining a world point from a screen point with an orthographic projection

I assumed this was a straightforward problem but it has been plaguing me for days. I am creating a 2D game with an orthographic camera. I am using a 3D camera rather than just hacking it because I ...
5
votes
3answers
4k views

Why / how does XNA's right-handed coordinate system effect anything if you can specify near/far Z values?

I am told repeatedly that XNA Game Studio uses a right-handed coordinate system, and I understand the difference between a right-handed and left-handed coordinate system. But given that you can use a ...
5
votes
3answers
597 views

Is there any algorithm for creating 3D lightning?

Is there any algorithm for generating lightning? Lets say, you input the starting and ending coordinates (x,y,z) and out comes an array of coordinates to show where the lightning goes. It doesn't have ...