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Questions tagged [matrix]

A 2D array of numbers, symbols or expressions, arranged in rows and columns. Each row must have the same number of columns. The numbers, symbols or expressions themselves are called elements or entries.

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497 views

Help Understanding Cameras/View Matrices in DirectX11 (C#)

So I'm designing a soft game engine in C# on top of the SharpDX API (a C# wrapper for DirectX). As I'm designing the camera, though, I'm running into some issues getting the 3D perspective correct. I'...
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Rendering perspective independent polygons in perspective view

I am creating an editor where I have "grabhandles" that can be dragged to transform a primitive object. My problem is that I can't find the correct solution to show these grabhandles in a perspective ...
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0answers
82 views

Cube Translation Looks All Wrong

I'm making a very simple cube in OpenTK and it seemed to be going fine until I tried to move it around. Moving it along the X Axis seems to elongate the cube, not the result I hoped for. My Vertex ...
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106 views

openGL Vertex Projection does not work as expected

I try to render a simple grid using glBegin(GL_LINES). I have a class Camera, which provides values like this: ...
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2answers
929 views

How do I create a view matrix that does not contain the camera translation?

I'm looking at this tutorial https://capnramses.github.io/opengl/cubemaps.html about half way down the webpage, there is a description of a vertex shader ...
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1answer
1k views

Passing Matrix to shader

I am learning HLSL and having trouble understanding how to pass matrices into the shaders to be able to perform the necessary operations within the shader to have the position values sent to the ...
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1answer
618 views

Getting world coordinates from mouse position

I am drawing a 2D mesh imported from CAD. The mesh vertex coordinates are in feet from some arbitrary origin and Z is always 0. I am supplying the coordinates to my shader program and using projection ...
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1answer
505 views

How to rotate to look at target

I have found other questions like this, but none seem to quite cover the situation I have. I am using DirectX 11 I have an object that has: Position (vector) Rotation (quaternion) View angle (pitch,...
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1answer
3k views

How would you design a transformation matrix to project absolute coordinates to any orthographic projection desired?

I am attempting to make an RTS based on AoE II HD Edition. I want to have ease of control by designing a transformation matrix given any style of projection I want. This is a good example of what I ...
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2answers
183 views

Drawing & transforming matrices upwards

I'm drawing a hierarchy of 3D objects in C# XNA where each objects has a transform that holds position, rotation and scale. I get my expected results If I draw my objects from my root node in this ...
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1answer
45 views

Transform point while keeping other points offset

I have the following situation: I've got a box with its center of mass transform matrix that I'm obtaining from physics simulation, i.e. it keeps changing with time. I've also got two points (actually ...
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2answers
163 views

Finding the Distance between 2 Objects

I have 2 objects One Having a Transformation Matrix T1 and other Having Transformation Matrix ...
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0answers
176 views

Understanding the ModelView Matrix

I want to analyze the each component of my 4*4 ModelView Matrix. I came to know that the starting 3*3 of ModelView Matrix ...
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0answers
143 views

Rotating an Object Around an Axis

I have a circular shape object, which I want to rotate like a fan along it's own axis. I can change the rotation in any direction i.e. dx, dy, dz using my transformation matrix. The following it's ...
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728 views

how to properly rotate in directX11

I am trying to Rotate a textured quad in directX however I think i am missing something. I am pretty sure it is because i am applying transformations to the WorldMatrix instead of the ObjectWorld, ...
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1answer
259 views

Vertex Skinning, Bone matrices question

I'm creating a model/animation viewer in C# using OpenTK for a game's models. Before stating my problem I want to describe a bit what I've accomplished so far in case I'm fundamentally missing ...
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1answer
77 views

2D World Mouse Coordinates - Matrices

I'm trying to get the world coordinates out of a mouse click. Currently I'm doing the following: ...
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1answer
359 views

Problem Rendering a Wireframe Cube and Grid with DirectX 11

I am trying to draw a 3D Wireframe (just the lines that connect each vertex) Cube and a 10x10 grid with D3D11. So far, this is my code ...
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1answer
196 views

How does a 4x4 matrix represent an object in space and matrix lore?

I have been following some tutorials on how Matrix maths works, with adding, dividing, scaling, etc, but I am struggling to understand how the 4x4 matrix represents an object's position in space. ...
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1answer
704 views

Translation Matrix not working properly

Hello, I get this result when i try to scale and then translate a vec4 in my shader. I created a mat4x4 class on my own and some functions wich return some matrices for me, everything works, but not ...
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1answer
107 views

Optimizing black and white matrix block drawing

Disclaimer: I am uncertain if this is the best place to post this question, so please advise me of how I can best find the answer if I am doing something wrong. I am asking this question because I am ...
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1answer
80 views

How to convert -1 to 1 coordinate back to screen coordinates?

Here is a question in which Questioner asks how to convert world coordinates to 1 to -1 coordinates like Opengl, I want to know how to do that in reverse, that given a coordinates between 1 and -1 (...
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1answer
388 views

js canvas tiled map - for loop, while, or matrix

I am making a top-down view tiled map in canvas, where player is always in the middle of the screen, and map scrolls depending on where you go, like in moba games. I also want it to loop infinitely in ...
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2answers
325 views

Get the difference between 2 matrices

Hi I'm using C# and MonoGame, and have the world matrices of 2 objects. I need to get the difference between them, so I can ...
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1answer
345 views

DX11 Camera not working properly

I'm currently trying to implement a ArcBall Camera which should fly around a given XMFLOAT3 position stored in a cb with a spezified distance to the position. I used the code from Allen Sherrod for ...
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1answer
3k views

Extract a rotation matrix given a camera direction (vector) and a up vector for the camera?

I am having some issues constructing a rotation matrix from a camera direction vector. The Up vector is computed from the camera direction as such: ...
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1answer
159 views

How to compute a transformation matrix that describes each position and rotation on a sphere?

I am having an issue constructing my transformation matrices, for this sphere problem. I know the 3d coordinate of the center, and the radius of, the sphere. Since I know the radius and center of ...
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2answers
2k views

Fastest way to neutralize scale in the transform matrix?

Let's assume we have 4x4 3D transformation matrix, that is the result of scale, rotation, and translation transforms. How to set its scale to (1,1,1) in the fastest way? Assume also that the matrix is ...
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0answers
115 views

How to spin a 2D quad in place using only matrices?

In short, I have a textured 2D quad (a sprite). I would like to rotate/spin it about the z-axis (coming out of the screen) using nothing but matrices. If I do the following to a transform with scale ...
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418 views

Control frustum near and far clip plane sizes in a Projection Matrix

I'm trying to achieve a dolly zoom effect. My first try was the obvious one, the original "zoom in & dolly out" technique, which works nicely. Except that there are cases which this is not ...
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2answers
838 views

OpenGL perspective matrix far plane

The near plane clips at exactly the value I set just fine but instead of clipping at 1000 the far plane clips at 1. Here is the code for the projection matrix: ...
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1answer
89 views

What are projection independent ways of determining whether a normal is facing the viewer?

A position v and normal n are given in world coordinates. Also there is a view matrix V for ...
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1answer
131 views

Projection Matrix Breaks My Rectangle

This is my vertex shader, shown below. ...
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1answer
2k views

How do you build a rotation matrix from a normalized vector?

I'm trying to find the correct way to build a rotation matrix from a unit vector. I have two arbitrary points in space (p1 and p2), and I'm trying to create the vertices for a rectangle to span ...
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1answer
1k views

OpenGL Arc-Ball Camera Yaw Pitch GLM::Rotate

I'm currently working on a small Voxel-Editor Project. In the editor, I plan on using an Arc-Ball camera which rotate around the model. My camera is currently working but in an odd way. I can't seem ...
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1answer
1k views

Convert transform from world to local space

I have a hierarchical node system. Given a world space transform, I need to obtain the transform for a specific node in local space. My Node class has the ...
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1answer
490 views

Mode 7 in xna/monogame

I want achieve a view like Mode 7 from snes games where the closer textures get stretched out more and more far away textures look smaller. Something like this: What I have in my project at the ...
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2answers
948 views

How to rotate camera using mouse?

I'm looking for a basic example of rotating camera using the mouse. the only problem is I'm not sure of how to rotating the camera around it target. should i do this by an algorithm or is there a ...
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2answers
150 views

Rotation, what is the Matrix?

From a previous question, thank you very much by the way, but what on earth is the Matrix of? I'm very new to Mono/XNA and finding any meaningful documentation is ...
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1answer
104 views

Recap on how a camera works in 3d Space?

This may be marked as a duplicate, but I have been trouble thinking about a camera. I understand that there is a "camera transform," or view matrix. However, this is multiplied with every vertex in ...
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1answer
210 views

Do matrix manipulations for 3D graphics ever produce singular matrices?

A singular matrix is a matrix that cannot be inverted. The vecmath library, for example, throws a SingularMatrixException if you try to invert a singular matrix. I think I understand what singular ...
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1answer
108 views

What is more efficient: Using matrix translation to move a character, or using a vector/scalar?

In 2D or 3D, matrix transformations are used for rotation, scaling, and sheering. However, when it comes to movement, should I go out of my way to use and implement scalar/vector movement, or just ...
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1answer
105 views

Terminology for the way Transformation Matrix Data is treated

I recently asked a question at math stack exchange and realize a similar questions is more suited for this forum, but the original is here: https://math.stackexchange.com/questions/1526601/...
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1answer
154 views

Last Row of the perspective projection matrix

Could you explain to me what is the purpose of -1 in the last row of the gl_projection matrix? And how it affects the perspective division step ?
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1answer
169 views

How can I get projected coordinates of vertex on screen

I want to check picking for faces and for that I need projected X Y coordinates of my vertexes in -1 to 1 range: For that I multiply my vertex array with matrices and then get projected triangle ...
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2answers
2k views

Cumulative transformation matrices for hierarchical object transformations

I'm having a small issue with my design for hierarchical 3D objects. I'll try to sum things up concisely. Every object has a vector3 for its position, scale, and rotation, as well as a std::vector of ...
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0answers
624 views

Tweening back from arbitrary 3D rotation in javascript

I'm using a 3D javascript library to rotate the vertex of a 3D object with a classic 3x3 matrix, to an arbitrary angle in the 3D space, as depicted in the image below. For example, a first rotation ...
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1answer
324 views

Change value of uniform for each VAO

I've heard from several sources that it's a better approach to pass the model matrix to a shader via a uniform rather than an attribute. I also know that the idea of a uniform is, that it has the ...
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1answer
692 views

Applying Transformation Matrices to VBOs in OpenGL

So I've recently tried to add Vertex Buffer Object Matrix transformation to an OpenGL engine I'm working on. I could go about this by applying the matrix to a copy of each vertex individually, but ...
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2answers
78 views

Strange behavior with transformation matrix

I'm fairly new to transformation matrices. I'm using them to translate and rotate nodes and their child nodes. The following code works when applied once, but shows strange behavior when applied many ...