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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13 views

Adding a 2D transformation matrix to GLSL

I'm having trouble understanding the matrices I need to render an object in OpenGL. I've been using a matrix to make up for the translation and scaling from the camera in my game but I didn't have a ...
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1answer
26 views

What are suitable and latest ranking system for racing games? [closed]

I have been developing a game for iOS. I am not able to figure out a ranking system for the game. Can someone suggest most frequently used and best ranking systems.There will be a user who will be ...
0
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1answer
44 views

Rotate heading relative to agent's local space

I'm having a little trouble translating a point in my game's world space to an object's local space. I have a cannon in my game with a normalized heading vector that's always supposed to point in the ...
5
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1answer
205 views

How can I convert OBJ data into CSS3D transformations?

I want to convert the data in a 3D .obj file (vertices, normals, faces) to CSS3D (width, height, rotateX,Y,Z and/or similar transforms). I found a bunch of formulae and what-not, but 3D isn't my ...
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1answer
230 views

What is the 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 ...
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0answers
19 views

Determine local “roll” from matrix

I'm allowing my player to maneuver freely in three dimensions. The world is very cubical, so it is useful to know internally (to help hint controls) which ground plane they're closest to paralleling. ...
2
votes
1answer
605 views

multiply matrix by vector: what to do if need to change y-up to z-up?

I multiply a matrix with a position vector to get a new position, however, now I need to change my matrix from y-up coordinate space to z-up. Changing only the matrix won't work: how to apply the ...
3
votes
1answer
174 views

How to make an object stay relative to another object

In the following example there is a guy and a boat. They have both a position, orientation and velocity. The guy is standing on the shore and would like to board. He changes his position so he is ...
3
votes
1answer
349 views

Retrieving model position after applying modeltransforms in XNA

For this method that the goingBeyond XNA tutorial provides, it would be really convenient if I could retrieve the new position of the model after I apply all the transforms to the mesh. I have edited ...
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1answer
156 views

Relative Position/Rotation calculation

I have 2 objects each with a 3x3 Matrix (Orientation) and a Vector3 (Translation). Both are relative to world coordinates. How do I calculate the position and orientation of object B in relation to ...
0
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1answer
58 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 ...
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1answer
108 views

libgdx - Box2d debug draw not correct

I have a problem where the bodies in my debug draw does not draw correctly, take a look: As you can see, there is some space between the dynamic body and the ground. I have checked the contact ...
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2answers
63 views

Problems with Rotation Matrices on Certain Axes

Here is what my rotation matrix looks like: public Matrix4f initRotation(float x, float y, float z) { Matrix4f rx = new Matrix4f(); Matrix4f ry = new Matrix4f(); Matrix4f rz = new ...
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3answers
191 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
235 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
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0answers
32 views

Coordinates estimation

Hi im using artoolkit to extract the coordinates of the marker im detecting with the camera. I need to know the values returned when arGetTransMat is the coordinates (x,y,z) which is returned ...
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2answers
748 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
651 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 ...
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1answer
49 views

Java OpenGL Perspective matrix not working

I'm trying to render a simple triangle with OpenGL in Java using LWJGL3. Everything is working great, but the projection matrix (perspective) is not working. In C++ I just used to apply the ...
1
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1answer
89 views

Pre-calculating skeletal animation data

I'm working on skeletal animation and so far I've got the skeleton drawn with interpolated animation working (just on the cpu still). I was thinking about changing my file format for my skeleton and ...
0
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1answer
101 views

How do I ADD gravitation to a rotation matrix?

I have ported the Matlab script from https://instruct1.cit.cornell.edu/courses/bionb441/LSystem/ to POV-Ray and everything works fine (although I'm not quite sure why). To navigate a "turtle" through ...
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0answers
29 views

OpenGL - Cubemap “Rotating” Proportional To Camera Movement

I'm doing a simple planet rendering project and am running into an issue with accessing cubemap textures correctly. The planet terrain is generated using the diamond square algorithm done 6 times and ...
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3answers
56 views

Problems Animating Texture in OpenGL

I'm trying to animate a texture to scroll a static screen for a television, however I'm having some issues. Just translating within the texture matrix animates all textures in the scene which is ...
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2answers
52 views

How can I calculate the orthographic projection needed to encompass an object with arbitrary rotation?

So I need to set up the dimensions of a orthographic projection that will encompass the entirety of a bounding box when viewed from any arbitrary position. That's an eye (programmer art); and the ...
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0answers
56 views

OpenGL model transforms wrong on AMD GPU

I've been writing a program that uses OpenGL to display some simple 3D models (rays, cuboids, spheres and simple meshes). I am targeting the programmable pipeline in OpenGL 3.2. So far I have been ...
0
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1answer
51 views

how to stop camera at the end of world map when zoomed in

Im building a tile-based game, and Im trying to implement zooming in on the center of the screen. My problem is, when I get to the edge of the map and im zoomed in, Im noticing that my camera doesn't ...
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2answers
73 views

OpenGL: Is it efficient ok to glPushMatrix, plMultMatrix, plPopMatrix for every object in my scene?

I'm very new to opengl, and I might not fully understand the openGL matrix projection stack thing. So, I have about 300 'objects' in my scene, each with their own position/rotation, and I want to ...
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0answers
43 views

Confused About My Code Suggesting The Normal Matrix Is Equivalent To The ModelView Matrix

I'm learning environment mapping in OpenGL by following this page. In his vertex shader, the author calculates the vertex normal in eye space with the following code: nEye = vec3(viewMatrix * ...
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0answers
21 views

2D viewport matrix World to Local coordinates

I would like to use a Matrix but it causes (or I think it does) problems with accuracy. Clearly classic float matrix causes jaggy movement/accuracy issues. The reason is that my objects have real ...
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0answers
24 views

change position/orientation of a bone using assimp

I have been using assimp to import rigged models and animations. I followed this tutorial for skeletal animation and I have got it done properly. The part that I am trying to do now is to orient a ...
11
votes
3answers
368 views

Rotate object around fixed axis

I am trying to let the user of my app rotate a 3D object drawn in the center of the screen by dragging their finger on screen. A horizontal movement on screen means rotation around a fixed Y axis, and ...
0
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0answers
38 views

Coordinate system in OGLdev tutorials

Working with OGLdev tutorials http://ogldev.atspace.co.uk/ I found that this code uses coordinate system, which doesn't look like in most other samples. Positive x-axis direction is left, and not ...
0
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1answer
38 views

Matrix Rotation Only Works On one Axis At A Time

I have this function in my vertex shader. It makes a transformation matix out of a transformation matrix, a rotation and an intensity. It works just fine when setting the rotation of one of the axis ...
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0answers
61 views

Pre- or post-multiplication for rotation between coordinate frames

I have three 3D coordinate frames: O, A and B, as shown below. I want to know the rotation matrix RAB between A and B, that is the rotation that is required, with respect to the frame A, to move ...
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1answer
34 views

Inline-Building a World (SRT) Matrix

Currently, to construct a world matrix, I have the following code: return FromScale(scale) * rotation.RotMatrix * FromTranslation(translation); However, this is constructing three matrices, and ...
58
votes
9answers
22k views

Why do we move the world instead of the camera?

I heard that in an OpenGL game what we do to let the player move is not to move the camera but to move the whole world around. For example here is an extract of this tutorial: OpenGL View matrix ...
4
votes
3answers
273 views

Why do we refer to a “model view” matrix and not a “viewprojection” matrix?

Why there is a model-view matrix, but not a view-projection matrix? A view-projection matrix would make much more sense to me, since every entity in the scene has his own position and therefore its ...
2
votes
1answer
146 views

Project rotated matrix to isometric coordinate

I have a group of soldiers, and each has a vector describing their position in the squad. When the group rotates, I do this math to calculate the desired position of each soldier. var unitPositions : ...
0
votes
1answer
154 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 ...
0
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0answers
25 views

Use Android 4x5 ColorMatrix in OpenGL ES 2 Shader

I am trying to use Android Color Matrix in OpenGL ES 2. I have been able to use a 4x4 Matrix using the following code in the Shader (this adds also an intensity parameter): varying vec2 ...
0
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0answers
38 views

GLSL billboarding

I want to make billboarding using GLSL. For what I've got so far it works, but not exactly the way I want. My vertex shader looks like this: #version 120 uniform float partSize; varying vec2 ...
0
votes
1answer
72 views

Scaling world - projection, view or separate matrix?

I am currently writing a simple 3D space visualisation program. Things get loaded into it from a simple XML file, which contains positions and sizes of objects in space, so you can put basically any ...
0
votes
0answers
67 views

Matrix, vector multiplications in OpenTK

I developed a 3d model viewer in c++ with OpenGL, and in c# in OpenTK. Both are using the same shader, but the output from OpenTK is not correct. I read that OpenTK is row major order, and OpenGL is ...
0
votes
1answer
55 views

Binding an Instance Matrix with an InputLayout

If I want to bind an instance matrix to a vertex shader, how do I go about it? For example, here is a super-simple VS input: struct VS_IN { float4 Position : POSITION; row_major float4x4 ...
1
vote
1answer
100 views

How to position a Weapons model in a first person shooter with XNA

I am building a first person shooter and positioning the weapons is hard. I am trying to get the bat to look like you are holding it but I keep trying things and they don't appear in the positions I ...
1
vote
0answers
52 views

How can I approximate an “opening fan”-transformation?

Is there a way to—with matrices—transform something as if opening the image on a Japanese folding fan? Image from Wikimedia Commons. I'm at a loss of what to call it, so pointers towards avenues of ...
4
votes
1answer
60 views

How can I find the minimal texture size so the texture requires no pixel interpolation when transformed by a given matrix?

Given a rectangle with width x and height y, and a transformation matrix T: How can I estimate the minimal resolution of the texture (that is, its width and height) such the interpolation of ...
3
votes
1answer
104 views

what is the very last element of a 4x4 transformation matrix for? [duplicate]

while its a similar value to its neighbour - Z translation (and I wont say if thats above or to the left for fear of sparking a religious war!) and it only seems to change when the Z translation value ...
1
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1answer
130 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 ...
3
votes
1answer
94 views

What is FOVx in this diagram?

a beginner game developer here. I have recently taken upon learning about 3D game development and I am stuck on a simple matrix problem. The image is found from this article: ...