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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2
votes
1answer
102 views

OpenGL light appears to move with camera and changes with object rotation

I have a working open gl es 2.0 3d engine (my own) that I've used in several iOS apps. I recently noticed that on a mutli-symmetrical object the lighting didn't look the same at each rotation. For ...
0
votes
0answers
20 views

Connecting a model's joint to the joint of another model

I am trying to figure out the math behind orientating and translating a model so that a specified point on the model will connect with a specified point on another model. For example, given the ...
0
votes
0answers
11 views

Implement Camera (former: CCCamera) v2 in cocos2d-x v3.3

we want to port camera code from cocos2d-x version 2 to version 3.3 with the goal to imitate the behaviour of a CCCamera in cocos2d-x version 2 exactly. You can assume that values for "eye" and "up" ...
-1
votes
0answers
17 views

Perspective based Isometric Projection [on hold]

So i am currently developing a game and i am trying to come up with a solution to this problem and i though you guys could help. So i am developing a Isometric based game that will be in a 3D space ...
0
votes
1answer
96 views

how to retain the animated position in opengl es 2.0

I am doing frame based animation for 300 frames in opengl es 2.0 I want a rectangle to translate by +200 pixels in X axis and also scaled up by double (2 units) in the first 100 frames Then, the ...
1
vote
3answers
134 views

2D HLSL World position

I'm trying to get world position from my vertex shader to my pixel shader so that I can disable the shader once a preset X coordinate has been passed (no shading once I'm over X). Getting the screen ...
1
vote
1answer
120 views

Correct multiplication order for a 2D Matrix

I'm currently trying to create a camera and entity/model matrix for my 2D game similar to that of Unity3D. I've already tried to find answers to this question on stackoverflow/gamedev but i couldn't ...
8
votes
3answers
754 views

How can I reverse the effect of a transformation matrix?

I have recently been working on a game with using OpenGL and C++ through GLFW. In the game I have an airship with a turret mounted on it. The airship moves around in world space coordinates and the ...
0
votes
1answer
71 views

Transformations and basis vectors

I've been reading this very nice tutorial on OpenGL, and I encountered a statement which I can't wrap my head around. In Chapter 6, it states: Transformation from one space to another ultimately ...
0
votes
1answer
26 views

Problematic cameraposition (Eye = (0,0,0), at=(0,-2,0) and up = (0,1,0))?

I am taking a course in computergraphics and we talk a lot about OpenGL and the math you need to do everything OpenGL does "by hand". A Question which was asked in an old exam (I am preparing at the ...
1
vote
1answer
212 views

Camera lookAt target changes when rotating parent node

have the following issue.I have a camera with lookAt method which works fine.I have a parent node to which I parent the camera.If I rotate the parent node while keeping the camera lookAt the target , ...
0
votes
1answer
69 views

Get 3D quad rotation matrix from points

I have 4 3D points which represent a even quad in space. (So 3 points are sufficient) I need to get all the individual transformations (translation, rotation, dimensions) so that I can build that quad ...
0
votes
1answer
38 views

Directional lights (not) rotating with camera (opposite problem)

I am trying to implement a shader for directional lights correctly, but I am bit confused as to why it works when it shouldn't and vice versa. People usually encounter problem with lights changing ...
1
vote
2answers
443 views

Matrix rotation wrong orientation LibGDX

I'm having a problem with matrix rotation in libgdx. I rotate it using the method matrix.rotate(Vector3 axis, float angle) but the rotation happens in the model orientation and I need it happens in ...
1
vote
1answer
606 views

importing animations in Blender, weird rotations/locations

This is for the Blender 2.6 API. There are two problems: 1. When I import a single animation frame from my animation file to Blender, all bones look fine. But when I import multiple (all of the ...
0
votes
0answers
41 views

Relative Transformations for Bones

I'm using Blender to export my armatures in relative coordinates, and I'm trying to get to absolute coordinates in my engine. For the above example, the childBone's tip is an offset of [-1,0,0], ...
2
votes
2answers
50 views

What is the meaning of the row “opposite” the translation column?

Usually, I do my matrix multiplication like this: [1 0 0 dx] | [px] [px + dx] [0 1 0 dy] | [py] [py + dy] [0 0 1 dz] | [pz] = [pz + dz] [A B C 1] | [1] [1] Where the translation is along ...
1
vote
1answer
54 views

How to fix model matrices colliding in vertex shader?

I am new to OpenGL programming and I'm writing some basic code to display a few objects onto a screen. I have a pyramid shape that I'm displaying, as well as a box shape that I am displaying. The ...
5
votes
1answer
114 views

Why bother with a separate normal matrix, if there is never non-uniform scaling on the view matrix?

I am updating one of my shaders to a version of OpenGL/GLSL that doesn't automatically provide gl_NormalMatrix (for educational purposes; I'm not ripping out working code for the sake of it). ...
0
votes
0answers
12 views

Transform screenquad around object's view space boundaries (GLSL)

Im not sure how to ask this, but essentially I am looking for a way to optimize rendering screen quad lights per object. I have a deferred renderer that draws directional lights onto a screen quad. ...
0
votes
0answers
56 views

XNA C# - Get original rotation from parent bone transform

I have a 3DS Max made model, exported into FBX and imported into XNA project. The parts I am working with have NOT been rotated in Max (specifically, collision mesh is made of Axiz-Aligned boxes). ...
0
votes
1answer
38 views

trasformation matrix for model's bones

I was developing an fbx converter for legend of grimrock object model (www.grimrock.net), I just wanted to get the animations cause the rest has been converted by others' tools. I was reading all of ...
0
votes
2answers
91 views

c# Unity - Matrix output incorrect on vector rotation

I have a input Vector (1,1,0) when I run it through a Unity Matrix4x4 class with a rotation of 90 degrees around the Z axis the output is (-0.9999999,1,0) which is nearly correct but strange. But ...
2
votes
1answer
45 views

XNA: How do I match Spritebatch View/Projection Matrices with BasicEffect Matrices?

I'm rendering a bunch of 2D content using SpriteBatches to a default XNA viewport. A simple 2D camera is used to move around the scene, which generates a transformation matrix passed to each ...
0
votes
0answers
49 views

3d Rotation problem

I was given an interesting (but tough) problem to solve: In a game, you want to change the heading of an enemy by +30°. Construct a Rotation Matrix, Euler Angles and a Quaternion that would do this. ...
0
votes
1answer
71 views

How can I get a 4x4 matrix from a bullet quaternion?

I'm trying to make a game using JavaScript with Ammo.js ( an implementation of bullet ) and Sylvester to do my matrix maths. The problem is I don't know how to turn the WXYZ that bullet gives into the ...
18
votes
5answers
2k views

Why do we use 4x4 matrices to transform things in 3D?

To translate a vector by 10 unit in the X direction, why do we have to use a matrix? We can just add 10 to the mat[0][0], and we got the same result too.
0
votes
2answers
387 views

Is this Rotation Matrix correct?

I'm having heavly troubles with setting up a View Matrix and a Projection Matrix. It simply doesnt work. So I think my problem is related to my rotationMatrix function. I'm using this tutorial to ...
-1
votes
1answer
65 views

MVP Matrix * Vector3 = Black Screen? [closed]

I'm relatively new to computer graphics so please take it easy. I created a ModelViewProjection Matrix and I sent it to my shader: #version 330 core layout(location = 0)in vec3 vert; uniform mat4 ...
0
votes
0answers
32 views

Apply android.graphics.Matrix transformation to an Open GL ES shader

I am currently using a 4x4 matrix to convert from "pixel" coordinates to OpenGL ones, my scene is full screen so my screen matrix looks like this: 2f / width, 0f, 0f, 0f, 0f, -2f / height, 0f, 0f, ...
2
votes
1answer
88 views

What AI algorithm to use to find hidden shapes in a Battleships-like game

I'm developing a game similar to Battleships, only using different shapes. A single type of shape will be used within a game session, by both the human player and AI. There will be several objects ...
2
votes
1answer
58 views

Distort a quad with a World Matrix

Is it possible to distort a quad multiplying its vertices by a specific world matrix? See the picture to understand what kind of distortion I need: Please note, that the quad is in 3d space and I ...
0
votes
1answer
100 views

New to OpenGL , having trouble understanding matrix transformation

I have modest experience of developing games with sdl , libgdx , unity etc. But never got into learning any low level API. So I thought about learning OpenGL and got started with tutorials provided by ...
2
votes
1answer
85 views

From 3d rotation, snap to nearest 90 directions

I have a 4x4 transformation matrix, made only from successive rotations and translations, and I'd like to "snap" my object to the "nearest" of the 24 orthogonal (multiples of 90 degree) rotations. ...
2
votes
1answer
55 views

Orthogonal projections question

I'm very VERY new into the game development world and I had just some slight trouble wrapping my head around something. We were told between classes just to think about how scaling matrices can ...
0
votes
1answer
55 views

Offset a camera/render without changing perspective

I need to offset a render so that the perspective / vanishing point doesn't change. Or another way to look at it is that I need to adjust the vanishing point in my view so that instead of being at ...
0
votes
1answer
215 views

How do I rotate and flip 2D sprites stored in a 1D array of pixels?

I am using a 1D array of pixels for rendering in 2D in java. I am interested in rotation (in radians) and mirroring across the x and y axes. The desired result looks something like this: Public void ...
1
vote
1answer
37 views

Camera world matrix to view matrix

I've been working on a game engine and I model every object in my scene graph as an "entity" this includes my camera. My camera therefore has a position and rotation in world space and at the moment ...
0
votes
2answers
168 views

Quaternion rotation, translation, scale or 4x3/4x4 matrices for Skeletons?

I'm modding a game that uses 4x3 and 4x4 matrices to make skeletons, but I saw that an skeleton can also be made with a quaternian rotation and vector translation and scaling. What's the difference ...
0
votes
1answer
70 views

XNA: Camera's Rotation and Translation matrices seem to interfere with each other

I've been following the guide here for how to create a custom 2D camera in XNA. It works great, I've implemented it before, but for some reason, the matrix math is throwing me off. public sealed ...
0
votes
1answer
86 views

Doing a turntable camera animation on a world matrix rather than view matrix

I have a camera class that contains a 4x4 view matrix as a member variable. Most of my camera controls work fine when doing them directly on the view matrix. In an attempt to unify all of my scene ...
5
votes
2answers
453 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)? ...
4
votes
2answers
199 views

How can I manually construct a right-handed orthographic projection matrix?

I need the formula to create a orthographic projection matrix. I am using GLM math libary and DirectX11. The reason I cannot use GLM to create it is because the NDC spaces are different between DX11 ...
1
vote
0answers
173 views

How should matrix-based Parallax Scrolling work?

The question is at the end, as it requires a bit of context. I'm not sure if my understanding, my code, or LibGDX's ParallaxCamera is wrong. LibGDX's ParallaxCamera uses Matrix4s to achieve a ...
1
vote
1answer
66 views

How do I combine matrix transformation with non-uniform screen scaling in Flash?

I'm using a Flash transformation matrix for affine transformation. I have a rectangular image being rotated and scaled (in 2D). There are two sets of scaling variables, ScreenScaleX and ScreenScaleY, ...
0
votes
1answer
89 views

Find world matrix

I'm making my first 3D-game with XNA (MonoGame) and have come to a point where I wish to add a crosshair for the player. To do this I need the on-screen coordinates of the location where my fighter ...
2
votes
1answer
124 views

What types of matrices are needed for game and graphics programming?

I am writing a 3D math library for general game development and want to know what type of Matrix classes I should include. Is just a 4x4 matrix enough, or must I provide 3x4 and dedicated rotational ...
0
votes
1answer
129 views

How are 2D transformation matrices applied to their targets?

I understand mathematically how transformation matrices work, in that a transformation matrix multiplied by a vector results in a new vector, and we use the matrices for rotation, translation, etc. I ...
0
votes
1answer
80 views

Blender animation to XNA distortion bug

I followed the instructions on the following video: http://www.youtube.com/watch?v=SissgQ0IXvk I'm using XNA 4.0 and Blender 2.69 I export the model with animation to a .FBX file. The animation is ...
3
votes
2answers
184 views

GLM/OpenGL: How Can I Prevent Vector Magnitude From Increasing While Rotating Bones in Skeletal Rig?

ANSWER AT THE BOTTOM OF THIS QUESTION I have been reading tutorials, articles, questions on StackExchange and books all with the subject of skeletal rigging. I have boiled my program down to just the ...