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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1
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3answers
432 views

Orthographic Projection with variable FOV

We are building agame with orthographic view. The problem we face is the fact that with different resolution you can see different area of the game world. E.g. if you have higher resolution you can ...
1
vote
1answer
229 views

HLSL What you get when you subtract world position from InvertViewProjection.Translation?

In one of NVIDIA's Vertex shaders (the metal one) I found the following code: // transform object normals, tangents, & binormals to world-space: float4x4 WorldITXf : WorldInverseTranspose < ...
12
votes
3answers
981 views

Camera for 2.5D Game

I'm hoping someone can explain this to me like I'm 5, because I've been struggling with this for hours and simply cannot understand what I'm doing wrong. I've written a Camera class for my 2.5D game. ...
2
votes
0answers
124 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? ...
0
votes
0answers
82 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
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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
1answer
695 views

View Matrix from Camera in Unity Script

I am looking to get a Camera component's "view" matrix in a script. I see that I can get the projection matrix using Camera.projectionMatrix, but I don't see a Camera.viewMatrix property... I want ...
4
votes
2answers
327 views

Precision loss when transforming from cartesian to isometric

My goal is to display a tile map in isometric projection. This tile map has 25 tiles across and 25 tiles down. Each tile is 32x32. See below for how I'm accomplishing this. World Space World Space ...
1
vote
1answer
818 views

Need to translate a Rotation Matrix to Rotation y, x, z OpenGL & Jitter for 3D Game

I am using the Jitter Physics engine which gives a rotation matrix: M11 M12 M13 M21 M22 M23 M21 M32 M33 And I need it so OpenGL can use it for rotation GL.Rotate(xr, 1, 0, 0) GL.Rotate(yr, 0, 1, ...
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 ...
2
votes
2answers
193 views

what is order of implementation of matrix transforms?

What is the meaning of Tr*Sh*Ro*Sc =M ? How is matrix M written to form the graphic transformation : 1st Sc=Scale, 2nd: R=Rotate, 3rd : Sh=Shear 4th: T=Translate ? Is the matrix M above written ...
0
votes
1answer
520 views

switching from third person view to first person view

I have done a scene in opengl where I'm using a third person camera (that I can control with the mouse). Then, inside it, it has the camera of the first view (that I called thirdpersonCamera, see the ...
1
vote
3answers
2k views

Replace glTranslatef and glRotatef with matrixes

I'm not an opengl expert, and, as a novice, I prefer to practice a little bit with the old opengl just to be sure to understand correctly the basic concept of computer graphics before deal with ...
2
votes
1answer
2k views

Combining rotation,scaling around a pivot with translation into a matrix

In short: I need to combine rotation (in the form of a quaternion), scaling around a pivot point along with translation into a transformation matrix. The long: I am trying to implement a proprietary ...
0
votes
2answers
262 views

How to properly translate a point by a matrix?

I wrote a simple Matrix class and it has methods like rotate, translate, etc. They all seem to be working, but whenever I try to translate a rectangle using the matrix, the translation axis seem to be ...
2
votes
1answer
105 views

Minimal Projection Matrix

i hope you can help me. I'm currently stuck at the creation process for projection matrices used by shadow maps. The problem is the following: I got the spot/directional light ...
0
votes
1answer
94 views

Last Matrix operation ignored?

I have 2 methods, one to rotate my Quad and one to flip it (using scaleM), they are as follows: (Note, all values in these methods have been properly defined). If I call just one, they work as ...
1
vote
1answer
180 views

Implementing axonometric bird-view in XNA

I made all kinds of logic (waypath, aso) for my strategical game, based on XNA (monogame). Now I "misused" the Vector2 a little bit: As I'm working from a "top-down" perspective, I'm using the Y-axis ...
1
vote
0answers
150 views

Matrix array doesn't seem to get populated [closed]

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# ...
0
votes
0answers
28 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 ...
1
vote
0answers
104 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 ...
0
votes
1answer
211 views

Trying to convert as3 Matrix to C++ glm matrix

I am trying to convert a library called DragonBones to C++ Opengl which allows you to use Flash based skeletal animation. I'm almost done but I am running into a problem. I am trying to transform the ...
1
vote
4answers
149 views

Storing tile grid in a matrix: row major vs column major

I'm using a generic matrix container to store the tile grid for my RTS game. This is where I am confused: a matrix is traditionally row major, i.e. matrix(0, 10) means 'at 0th row, 10th column.' A ...
1
vote
1answer
197 views

How can shears/reflections/enlargements be represented by 4x4 matrices? [closed]

I understand that 4x4 matrices can represent transformations on a 3d point (represented as x, y, z, w) Eg, a translation is [1 0 0 0] [0 1 0 0] [0 0 1 0] [x y z 1] where x, y and z are the amount ...
-1
votes
1answer
182 views

Pinhole matrix problem

I made a program to represent a 3D world. I use the projection matrix we can find on wikipedia. For viewing a scene it's very nice but when I straff in the scene, everything behind the camera go on ...
2
votes
1answer
207 views

XNA matrix order problem

I want a matrix that scales first and then rotates. I tried the code below, but it didn't work. zRotation, yRotation and xRotation are rotations that shouldn't be affected by the origin. allrot should ...
3
votes
1answer
244 views

Shear transformation in the projection matrix?

I am trying to understand what the shear transformation (l+r/r-l & b+t/t-b) is actually doing in the projection matrix? The only thing I got till now is headache :) Can you please help?
1
vote
2answers
361 views

Creating a 2D perspective in 3D game

I'm new to XNA and 3D game development in general. I'm creating a puzzle game kind of similar to tetris, built with blocks. I decided to build the game in 3D since I can do some cool animations and ...
2
votes
1answer
602 views

How to do directional per fragment lighting in world space?

I am attempting to create a GLSL shader for simple, per-fragment directional light. So far, after following many tutorials, I have continually ran into the issue: my light is specified in world ...
4
votes
3answers
322 views

Matrix multiplication - Scene Graphs

I wrote a MatrixStack class in C# to use in a SceneGraph. So, to get the world matrix for an object I am suposed to use: WorldMatrix = ParentWorld * LocalTransform But, in fact, it only works as ...
0
votes
1answer
131 views

Common way to store model transformations

I ask myself what's the best way to store the transformations in a model class. What I came up with is to store the translation and scaling in a Vector3 and the rotation in a Matrix4. On each update ...
1
vote
1answer
138 views

Matrix transforms in XNA

So in my most recent 2D game I draw objects like so. _spriteBatch.Draw(_sprite, Center(), null, Color.White, _rotation, new Vector2(_sprite.Width / 2, _sprite.Height / 2), _scale, ...
0
votes
1answer
815 views

What is the difference between a modelview-projection matrix and world-view-projection matrix?

So basically I wrote a shader a long time ago that uses all World and WVP matrices. Now I am working in an engine that will only give me access to ModelView, MVP, and model to world space matrices. ...
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 ...
2
votes
1answer
151 views

Manual GLU.gluUnproject

Before I used GLU.gluUnproject to calculate my picking ray in my OpenGL game. Recently I switched to my own calculated matrices, and now I can forget the gluUnproject. How can I calculate the picking ...
2
votes
1answer
182 views

Optimising skeletal animation

I am implementing a skeleton system for my latest game. I am using my own linear algebra classes which already have some optimisations, such as separate transformPoint and transformVector functions ...
3
votes
2answers
5k views

OpenGL - Understanding the relationship between Model, View and World Matrix

I am having a bit of trouble understanding how these matrixes work and how to set them up in relation to one another to get a proper system running. In my understanding the Model Matrix is the matrix ...
2
votes
1answer
167 views

OpenGL Calculate Matrices

Im trying to switch from the glTranslate etc to my own Matrices, but for some reason it does not work. Here are my 2 functions to create the view- and projection matrix: public Matrix4f ...
0
votes
1answer
236 views

Sharp DX Identity Matrix, Matrix.Forward vector pointing at negative Z

I'm trying to take a steady grip on Sharp DX. Already done some work like translating, scaling and rotating objects. Now i have to calculate the rotation matrix using only direction vector and ...
0
votes
1answer
88 views

What values to construct “Projection Matrix” from?

I am curious to what standard values I should use to create a camera's projection matrix, as well as if certain measurements need to be taken if I want to represent a very small world or a very big ...
0
votes
1answer
122 views

Getting Rotation Values From A Rotation Matrix

I'm trying to get rotation values along the x, y and z axis from a matrix that can include rotation, translation and scale data. Currently I have this function to return the y rotational value: float ...
3
votes
1answer
553 views

Rotating and Translating a Node in Horde3D with Matrices and Quaternions

I have been trying to learn how to use the Horde3D rendering engine for the past couple of days, and so far I have managed to learn a decent amount and integrate Bullet Physics with it as well. My ...
0
votes
1answer
129 views

XNA Camera Positioning All Wrong

I've been working in 3DSMax for years now and decided to give XNA 4.0 a try. I've got the majority of it working, however the camera is being a pain to me and I can't discern what's gone wrong. I ...
3
votes
2answers
170 views

What kind of projection is ScreenX=X/Z, ScreenY=Y/Z?

I have an existing class which transforms 3D vectors and projects them on a 2D plane (Camera). The code is all written in C without help from an external library. To project a single vector (X,Y,Z) ...
2
votes
1answer
403 views

Negative scale in Matrix 4x4

After some rotations and to from quaternion conversions I get negative scale from Matrix 4x4, is it possible? I need that scale to draw sprite on screen so I get sprite flipped, how to deal with this ...
2
votes
2answers
268 views

Java Tetris - Matrix Rotations

I'm building Tetris in Java and am trying to use linear algebra to rotate a piece composed of 4 tiles. My friend was explaining the way to do it is: He said: "To clarify, you do need to rotate ...
4
votes
3answers
1k views

Tetris - Rotations using Linear Algebra (Rotation Matrices)

I'm making Tetris in Java and am at the point of rotations... Originally I was hardcoding each rotation: if (direction.equals("right")) { if (shape.equals("Bar")) { if ...
2
votes
1answer
249 views

Translating Viewmatrix is inverted, why?

So I've defined a Projectionmatrix, Viewmatrix and a Modelmatrix using OpenGL (LWJGL). But when I translate my Viewmatrix to +X it moves my object to the right (hence my camera is moving to the ...
0
votes
2answers
115 views

Transform translation relative to world space

What is common algorithm for translating a transform matrix relative to world space axis? E.g. Matrix M is representing some local space. When I want to translate M relative to it's own local axis, I ...
2
votes
1answer
193 views

Camera not strafing (GLSL)

I use this code in my GLSL vertex shader, where v_position is the vertex position: gl_Position = v_position * u_camera; and set u_camera as follows: meshShader.setUniformMatrix("u_camera", ...