An array of numbers, symbols or expressions, arranged in row and columns. The numbers, symbols or expressions themselves are called elements or entries.

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4
votes
1answer
355 views

Getting the Bounds of a 2D Cameras View with Zoom

I am using a 2D camera, which does rotations and zoom. Currently, I am using the following to get my MinX, MinY, MaxX and MaxY... public float MinX { get { return ...
3
votes
1answer
1k views

Can a 4x4 matrix describe a camera's perspective?

I'm working with a closed-source 3D engine, and it only allows you to set the view projection via a 4x4 matrix. Can this matrix describe the camera's translation, rotation & perspective? I turned ...
2
votes
2answers
1k views

How can I transform a point from world space to object space?

If I have an object space described by transformation matrix that should be applied to object to transform it to world space, what I have to do to transform point (world space) to that object space. ...
2
votes
1answer
701 views

How to create projection/view matrix for hole in the monitor effect

Lets say I have my XNA app window that is sized at 640 x 480 pixels. Now lets say I have a cube model with its poly's facing in to make a room. This cube is sized 640 units wide by 480 units high by ...
7
votes
3answers
1k views

How do I adjust the origin of rotation for a group of sprites?

I am currently grouping sprites together, then applying a rotation transformation on draw: private void UpdateMatrix(ref Vector2 origin, float radians) { Vector3 matrixorigin = new ...
1
vote
1answer
3k views

matrix 4x4 position data

I understand that a 4x4 matrix holds rotation and position data. The rotation data is held in the 3x3 sub-matrix at the top left of the matrix. The position data is held in the last column of the ...
2
votes
1answer
231 views

Translating an object along its heading

Solved! I was not applying the transformations in the proper order. I am working on a simulation that requires me to have several objects moving around in 3D space (text output of their current ...
2
votes
1answer
373 views

How do I build a matrix to translate one set of points to another?

I've got 3 points in space that define a triangle. I've also got a vertex buffer made up of three vertices, that also represent a triangle that I will refer to as a "model". How can I can I find the ...
6
votes
3answers
794 views

Why is my model's scale changing after rotating it?

I have just started a simple flight simulator and have implemented Roll and pitch. In the beginning, testing went very well; however, after about 15-20 seconds of constantly moving the thumbsticks in ...
3
votes
1answer
589 views

Better data structure for a game like Bubble Witch

I'm implementing a bubble-witch-like game (http://www.king.com/games/puzzle-games/bubble-witch/), and I was thinking on what's the better way to store the "bubbles" and to work with. I thought of ...
4
votes
1answer
380 views

UVW: better explanation, and how to implement with GLES texture2D()

UVW texture coordinates, as opposed to UV texture coordinates, do not get very adequate explanation on the web. Many people offer the simple exlanation, "UV is for 2-dimensional textures and UVW are ...
10
votes
2answers
6k views

How can I rotate about an arbitrary point in 3D (instead of the origin)?

I have some models that I want to rotate using quaternions in the normal manner, except instead of rotation about the origin, I want it to be offset slightly. I know that you don't say, in 3d space, ...
4
votes
2answers
902 views

Ara matrices calculated on the GPU or on the CPU? Would built-in matrix functions be faster than my custom ones?

If I add a math library (for example containing a Matrix class) and use it in my program drawing with OpenGL, will my be work slower than if I used standard OpenGL functions for matrix calculations? ...
7
votes
5answers
2k views

Can someone explain the (reasons for the) implications of colum vs row major in multiplication/concatenation?

I am trying to learn how to construct view and projection matrices, and keep reaching difficulties in my implementation owing to my confusion about the two standards for matrices. I know how to ...
6
votes
2answers
2k views

Vector games (Wireframe, Elite-like) theory and implementations?

I'm interesting in knowing more about how vector games like Elite and Star Wars Atari were built from grounds up. The question is not how to implement vector graphics with modern 3D APIs like OpenGL ...
8
votes
3answers
1k views

Should I use a world matrix?

Image reference for the question: (image from the CG tutorial) The D3D9 API got us used to world matrices. However, if you use world matrices, then you have to do an extra matrix multiply in the ...
2
votes
2answers
1k views

How should I calculate world and projection matrices in this scenario?

I'm trying to understand transformation matrices. Suppose I use the camera from this StackOverflow answer, this is how my view matrix would look: Matrix.Identity * ...
2
votes
1answer
574 views

COLLADA: Inverse bind pose in the wrong space?

(Crosspost from StackOverflow) I'm working on writing my own COLLADA importer. I've gotten pretty far, loading meshes and materials and such. But I've hit a snag on animation, specifically: joint ...
0
votes
1answer
889 views

How to find which side of a collider has been hit from hit.normal?

In Unity3d, i can get the normal of the surface with which the collider collides using hit.normal, but is there a way to find which side has been hit what is provided bu Unity3d? One solution is to ...
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 ...
28
votes
1answer
27k views

What is the correct order to multiply scale, rotation and translation matrices for a proper world matrix?

Assume DirectX as the platform, if that is important. (Pretty sure it isn't) Assuming I have a proper scale, rotation and translation matrix, in what order do I multiply them to result in a proper ...
6
votes
3answers
2k views

XNA 4.0: 2D Camera Y and X are going in wrong direction

I asked this question on stackoverflow but assumed this might be a better area to ask it as well for a more informed answer. My problem is that I am trying to create a camera class and have it so ...
1
vote
1answer
1k views

XNA 2D Transform Matrix Scale at Zoom Question

This is the complete code I am currently using for my camera. It is incomplete and only partially understood by me (I am working off an example), but I have managed to hack some functionality with ...
6
votes
3answers
2k views

Direct3D and OpenGL Matrix representation

As I read in OpenGL matrices are column major. It means that if I create a 16 element array first four elements are the first column in matrix. Is it the same for Direct3D or any transformation's ...
8
votes
1answer
591 views

Downprojecting an imaginary 4D mesh to the screen

As a mental exercise, I'm trying to imagine projecting an arbitrary 4D mesh onto the screen (2D). I'm guessing a single 4D triangle would still consist of only 3 points, however each of those 3 ...
1
vote
1answer
197 views

Mesh to world vector translation

Suppose I have a world defined in typical OpenGL coords.. then the up vector defined for this space is (0,1,0). Now, if I load a model that is defined with (0,0,1) as its up vector, what are the ...
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
2answers
939 views

What is eigenvalue decomposition and why would it be useful in games?

In various math libraries developed for game engines, I see 2x2 and 3x3 square matrices having this function (along with some helper functions). I tried to find information regarding it but did not ...
5
votes
2answers
462 views

Is a dynamic enviroment map using pincushion curvilinear perspective projection possible?

I'm wondering if it is possible to generate a dynamic spherical environment map using a single frame render using a pincushion curvilinear perspective projection matrix (phew, that's a mouthful)? ...
6
votes
1answer
5k views

Help understanding gluLookAt()

I am fairly new to openGL( 3 months ) and am asking for assistance in understanding the fundamentals behind gluLookAt(). Currently I have spent most of my time with openGL modeling scenes with fixed ...
1
vote
1answer
171 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 ...
0
votes
1answer
322 views

Conversion from matrix defining rotation and position to camera matrix

I have a matrix that defines the rotation and translation of an object, relative to (0, 0, 0). Assuming that the identity matrix defines the camera to be at (0, 0, 0) pointing at (0, 0, 1), how would ...
7
votes
2answers
572 views

Portal Projection

Ok ok I admit, I'm bored and toying with a portal script like the one on steam. I've figured out the following: relative positioning of the mirrored cameras render to texture for the portal (the ...
5
votes
1answer
745 views

Problem with DirectX scene-graph

I'm trying to implement a basic scene graph in DirectX using C++. I am using a left child-right sibling binary tree to do this. I'm having trouble updating each node's world transformation relative to ...
4
votes
3answers
4k views

Inverting matrix in HLSL

I've got an object in HLSL and I'm using hardware instancing to render multiple copies. But I've come a bit of a cropper when it comes to the vertex normals. Currently I am not using normal mapping ...
2
votes
2answers
1k views

How do I calculate an offset from an Object based on the Objects Rotation rather than the World Space

I have a Matrix of a player & I want to create a second location a set distance away from the first location but I want the second matrix to be set a set distance based on the rotation of the ...
3
votes
1answer
363 views

Is there are a good double-precision small matrix SIMD library for x86?

I'm looking for a SIMD library focused small (4x4) matrix operations for graphics. There's lots of single precision ones out there, but I need to support both single and double precision. I've looked ...
13
votes
6answers
5k views

Math topics for 3D graphics programming

I understand that the following math topics are required for 3D graphics programming. I have started doing some of them in my math course. Can someone point me in the direction of a resource that ...
4
votes
1answer
525 views

Managing Game Entity coordinates

In my Game I'm currently have "Scene Coordinates" which are the X,Y coordinates relative to a Game Scene. In that Scene there are Game Entities, let's say there's a GameEntity A in x=100.0, y=100.0 ( ...
4
votes
4answers
1k views

From camera coordinates to world coordinates

I want to calculate world coordinates from camera coordinates. However, I seem to have problems with my understandings of how matrices in HLSL work. From world to camera is clear: cameraPosition = ...
5
votes
1answer
332 views

Realistic damage

I'm looking for a good way to simulate damage, for example a weapon firing at a ship it would calculate the damage depending on layer type, weapon type, angle and similar what i need is a way to to ...
2
votes
1answer
267 views

Why doesn't the y Axis work with SuperBible frame reference or GluLookAt

I'm currently trying to understand how to use the GLFrame Class in the superbible book, and acording to the 4th edition of the book, the camera matrix derived from the Frame of reference class should ...
1
vote
2answers
437 views

opengl rotations for a human

I currently can rotate around a pivot point by first translating to the pivot point then performing the rotation and finally translating back to the origin. I do that easily enough for the shoulder in ...
4
votes
1answer
3k views

How to create a perspective field of view matrix?

Hey, hello. I am learning a little of WebGL (OpenGL ES 2.0) through the http://learningwebgl.com tutorials, but it uses a third party library to create the View, Projection and transformation matrices ...
4
votes
1answer
261 views

Projecting onto different size screens by cropping

I am building a phone application which will display a shape on screen. The shape should look the same on different screen sizes. I Decided the best way to do this is to show more of the background on ...
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 ...
1
vote
1answer
1k views

Restoring projection matrix

I am learning to use FBOs and one of the things that I need to do when rendering something onto user defined FBO, I have to setup the projection, modelview and viewport for it. Once I am done ...
4
votes
2answers
6k views

View matrix in opengl

Sorry for my clumsy question. But I don't know where I am wrong at creating view matrix. I have the following code: createMatrix(vec4f(xAxis.x, xAxis.y, xAxis.z, dot(xAxis,eye)), vec4f( ...
2
votes
3answers
2k views

Interpolating Matrices

Apologies if I am missing something very obvious (likely!) but is there anything wrong with interpolating between two matrices by: float d = (float)(targetTime.Ticks - keyframe_start.ticks) / ...
13
votes
5answers
660 views

Is there a common word that encompasses handling of position, rotation, and scale together?

I'm looking for a name for my class that manipulates 4x4 matrices that handle position, rotation, and scale. Is there a common word that encompasses all three? (I'm splitting the matrix math into its ...