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

learn more… | top users | synonyms (1)

1
vote
2answers
288 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
75 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 ...
1
vote
1answer
204 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 , ...
1
vote
1answer
578 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
1answer
70 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
votes
1answer
47 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
101 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 ...
2
votes
0answers
117 views

Unproject considering parallax depth

How can I take screen coordinates (or alternatively world coordinates on the 'primary' parallax plane) and find out what world coordinates they translate into when taking parallax depth into account? ...
1
vote
0answers
160 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
0answers
135 views

Matrix array doesn't seem to get populated

I'm trying to stream an array of matrices to a vertex shader, but it seems that only the first matrix works. What could be the problem? I suspect that I upload the matrices in a wrong way. C# ...
1
vote
0answers
96 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 ...
1
vote
0answers
104 views

Rotate Points with Object in world space

I posted this in the original stack overflow then realized that a game-dev specific one exists. I am working on personal project that requires me to have 4 points surrounding an object (1 at each of ...
1
vote
0answers
403 views

Stacking Drawing Matrix for SpriteBatch in XNA

I'm trying to make a 2D engine for XNA with SpriteBatch. My object unit is Entity, which can include other Entities as its children. However, when drawing them, the rotation and scaling stacking do ...
1
vote
0answers
182 views

How do I implement a physics gun?

I'm currently trying to implement a physics gun for my game. What I want is for the entity to stay in the same position on the screen no matter how I wiggle the camera about, what is the correct way ...
1
vote
0answers
280 views

Drawing two orthogonal strings in 3d space in Android Canvas?

I want to draw two strings in canvas. The first string must be rotated around the Y axis, for example 45 degrees. The second string must start at the end of the first string and also it must be ...
1
vote
0answers
268 views

Matrix.CreateBillboard centre rotation problem

I'm having an issue with Matrix.CreateBillboard and a textured Quad where the center axis seems to be positioned incorrectly to the quad object which is rotating around a center point: Using: ...
1
vote
0answers
213 views

How do I convert my matrix from OpenGL to Marmalade?

I am using a third party rendering API, Marmalade, on top of OpenGL code and I cannot get my matrices correct. One of the API's authors states this: We're right handed by default, and we treat y ...
1
vote
0answers
238 views

Getting and Setting Rotation in XNA around the Center of my Model with XNA

Alright, so I'm currently debating how I want to do this. Basically this is what I'm trying to accomplish. I've created a system to allow me to make my environment a little bit easier. I'm ...
1
vote
0answers
210 views

what space is this Matrix in?

In Blender 2.6 API, PoseBone is used for animating a bone. PoseBone.matrix is one way to do that. API says PoseBone.matrix is in "object space". ...
1
vote
0answers
162 views

reflection plane 3d

Hey there I'm trying to create a plane that can have a texture on it and reflect the 3d elements around it. for example a plane with a laminate floor texture and above it a cube rotating. I want the ...
0
votes
0answers
12 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, ...
0
votes
0answers
31 views

XNA - Link between Create Rotations matrices

A friend of mine have been coding some rotations on my XNA project, but the order of the matrices rotation are not good. Some are of form : Matrix.CreateRotationZ(1.21f) * ...
0
votes
0answers
69 views

Matrix Translate Camera has some sort of spiky movement

public class Camera2D { private Vector2 _position; protected float _viewportHeight; protected float _viewportWidth; public Vector2 ScreenCenter; protected Being _unit; // the sprite camera is ...
0
votes
0answers
31 views

Checking if a object is blocking my view of a light (it's between light and camera)

I'm trying to determine, from a list of objects, which ones are blocking my view of a light. In other words: which ones are between the light and the camera. Coding in C++, using HPL1Engine. This is ...
0
votes
0answers
125 views

Alter a model-view-projection matrix

I have a model-view-projection matrix created based upon my camera. Is it possible to make alterations to it after it was computed to affect the corners of the resulting camera frustrum? For example, ...
0
votes
0answers
58 views

“Blinking” graphical bug when rotating shadow matrix

So, we have implemented Krypton shadows into our code for our 2D game, and it's working beautifully. Only issue is that we're running into a bizarre graphical bug when rotating the shadows with the ...
0
votes
0answers
63 views

W2S, worldtoscreen from Projection Matrix and View Matrix

After a couple of days of tremendous trial and error coding, I must give up: I have a simple 3d program that I'm adding a visual layer to. Basically, I want to draw 2d icons and text over 3d objects ...
0
votes
0answers
81 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 ...
0
votes
0answers
30 views

Is there a transformation or set of transformations that can approximate a “radial scale”?

Is there a way to, with matrices, scale something as if someone were opening a Japanese fan? I'm at a loss of what to call it, so pointers towards avenues of research would be greatly appreciated. If ...
0
votes
0answers
118 views

Why my camera sees what is behind it?

I am building a minimal opengl viewer and I am puzzled by what I see : the camera see the (test) object that is behind her. the front and back of the camera looks reverted. I am wondering what could ...
0
votes
0answers
26 views

Constrain parent node transform to child bounds

If I have some node rendering tree set up, where a node basically has a draw method to render things, and a transform, represented as a 3x3 matrix, with scale and translation. Now, I would like to ...
0
votes
0answers
66 views

Transform a Screen Delta

I have a delta in screen coordinates that I want to transform to a 3d delta in world space. The delta is in this case a movement across the (x,y) coordinates in screen space on the near projection ...
0
votes
0answers
424 views

Calculating the correct roll from a bone transform matrix

Read this forum topic for more info: http://blenderartists.org/forum/showthread.php?260602-transform-matrix-to-bone-%28head-tail-roll%29-bug I'm trying to get my Blender3d modeller importer to create ...