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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Rotate UVs in shader and contains result into quad with repeat edge pixels
I ask for help - I need to rotate the UV scan inside the quad by a certain angle (set by a parameter) so that the result is embedded in the original UV, and the missing areas are repeat edge pixels. ...
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How to correctly rotate 2D orthographic projection around a central point?
I want to rotate a 2D orthographic projection around the centre point of my view. However, something is off (it looks like a translation) but I'm not sure what.
To put some concrete values on the ...
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Isometric camera lookat
I'm trying to make my isometric camera follow my player or lookat any other object
projection matrix is
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Inertia Tensor Relative to Center of Mass vs Inertia Tensor in Body Coordinates
If I have the inertia tensor relative to the center of mass, is that the same as the inertia tensor in body coordinates?
If no, can you please explain the difference and how do I numerically calculate ...
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Screen position in Deferred Shading
I am trying to implement a program in Direct3D 11 which uses techniques like deferred shading and shadowmapping, but when I create my gBuffers, the position looks strange. After researching a bit I ...
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How to set up view and model matrices for 3D rendering?
For various reasons I am building a very simple graphics engine. I have a pretty good 2D thing using plain SDL2 and C that essentially boils down to a single "putpixel" function. I can ...
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Error in directional light shadow projection matrix
I have VC++ code for DX9 that draws shadows perfectly.
...
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3d camera control on XY plane controlled by mouse
I am creating a 3d game with a isometric view. I have a problem implementing camera controls. I can control angles of camera, but my view is scrollable only in the XY axis (camera is always up, Z axis)...
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Align two meshes given 2 faces
I have two meshes (A and B) and I know that a triangle in A has the same size and same angles as a triangle in B.
For simplicity, suppose A is an octahedron and B is a tetrahedron. And suppose the ...
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Implementing a Maya-like orbit camera in Vulkan/OpenGL
I want to create an orbit camera with zooming, panning, and rotation. I used the following examples to create cameras:
https://stackoverflow.com/questions/54400422/how-to-implement-altmmb-camera-...
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Calculating LookAt position from rotation and translation matrix
I was wondering if it was possible to calculate a lookat position from the translation and rotation matrices (aka the building blocks of my view matrix). I need the lookAt position to implement a ...
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Find coordinates in one space from another
I'm trying to determine what coordinates are in one space when given a point in another space.
For example, I've got a Matrix4x4 that I can use to convert a point in unity's world space to a skewed ...
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correct matrix to draw mesh as flat object
I need to draw a tilemap for a 2d game. For that I created vertices with their relative positions already hard baked. The coordinates start top-left with (0f, 0f) and z is always 0.
I rendered them to ...
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Removing duplicates/ignoring them from a 2 dimensional Array
I have a bool[,] Array for keeping track of Nations that are either at war(true) or neutral(false).
The problem Im having is that when going over the matrix, to display al wars in UI elements, it will ...
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Object stuck to screen no matter what eye position is used
I've run into an issue when trying to write a simple rendering program in D3D11. I'm 90% sure it's to do with some faulty matrix multiplication or generation, but I've tried debugging the values of ...
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How to convert a 4x4 matrix transformation to another coordinate system?
Is there a general method to convert a matrix transformation from one coordinate system to another, so that the resulting transformation looks the same on screen?
For example:
There are some ...
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Setting glOrtho and glViewport so top-left of window has coordinates (0,0)
I haven't used OpenGL for a long time and have trouble setting up a 2D screen where the upper left window coordinates are (0,0) and the width and height of the ...
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Transforming 3d point for depth testing
I have a ray and its direction is (o,d). Multiply it by the model matrix to rotate the model.
...
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How does this 4 by 4 matrix (about 4 points are coplanar) come up with this equation?
I have just begun learning some 3d mathematics and OpenGL (trying to implement skeleton animation).
I am stuck here when reading a book(Advanced Methods in Computer Graphics). I understand the first ...
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Efficient calculation of billboard sprite transformations
I'm currently adding a billboard mode to animated sprites and static sprites in my 3D engine.
The code below works fine, but I want to know if a more optimized solution exists. I've heard about ...
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How to convert a list into coordinates in pygame
I'd like to have a map in my pygame game but don't want to waste time moving each individual object in it. To resolve this, I'd like to iterate over a list like this:
[1, 0, 0, 0, 0,
0, 0, 0, 0, 0,
0, ...
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Calculating bone transformation matrix for vertex skinning
I have an issue with calculating transformation matrices for animation mesh deformation using glm in c++
I have a class Bone which does the basic calculation which does have a current local position (...
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Understanding matrix transformations for skeletal animation
I am working with Collada and GLTF.
Say I have a humanoid with 3 bones with the following hierarchy: B0(root) → B1 → B2.
Terminology:
bind pose is the same thing ...
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Apply a mocap to multiple different models? -> modify gltf directly?
I am currently struggling with an animation I made that I would like applied to multiple models, all different, but from the same vertices.
I already have a custom gltf importer ready but I need to ...
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Why would some assets require a transposed TBN matrix?
I'm writing an OpenGL/DX11 Windows/Linux "engine" and I've encountered a confusing behavior in DX, specifically. For math, I'm using GLM, which means all of my HLSL ...
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Matrix math: How to specify camera distance so that an object with a given size is completely visible?
This is my code that draws a top down view tile based map. But Iam do not know how high the camera needs to be placed in the sky so that the map is fully visible so that nothing is cut away and I do ...
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How to calculate camera view matrix from world transform, specifically the orientation?
In my engine, camera is just any other object in the scene. It has a transform -- position, rotation (quaternion), and scale (ignored for camera view matrix). I want to convert this to the camera's ...
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Find out (general) orientation of cube faces with rotated and translated camera
I have the following problem. I have a camera that is initially looking at a cube. The cube is with center at (0, 0, 0). The camera that is initially on (0, 0, 60). The camera can rotate and translate ...
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Speed up Reaction-Diffusion simulation calculations in Unity
I'm trying to use Unity Job system to speed up some calculation related to Reaction-Diffusion simulation. The calculations requires 2 matrixes, current and ...
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How are transformation matrices usually represented?
I know the bare minimum to do matrix multiplication and have implemented them from scratch a few times for various purposes, but every time I do, I make sure to be very clear to myself about where are ...
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How to decompose a GLSL mat4 to original RTS values within vertex shader?
I need to get the rotation differences between the model and the camera.
convert the values to radians/degrees and pass it to the fragment shader.
for that I need to decompose and the Model rotation ...
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What is the correct way to combine transforms together?
I have a type called transform in my game engine:
...
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How to define custom coordinate space?
I'm trying to build small UI framework. And I want it to have a coordinate space such that origin is placed in top left corner (x increases to right, y increases to down). I think for UI it should be ...
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Get local position of a skinned vertex
I have a formula for skinning, where a vertex is attached to 2 joints with some proportions:
B = M1*A*K1 + M2*A*K1
Where:
K1 and K2 are the proportion ...
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Meshes seem to get distorted when I use rotate or zoom transforms (XNA/Monogame)
Whenever I seem to create a rotation matrix or try to zoom, the meshes that I draw to the screen get stretched and distorted.
I've tried to make a simple rotation matrix like this:
...
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How to solve for the angle of a axis/angle rotation that gets me closest to a specific orientation
I’m using a 3D affine transform (a 4x4 matrix of floats) to represent a combination of translations and rotations in 3D space doing a sort of 3D turtle graphics kind of thing.
From this state I know ...
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Right Axis warps on 3D planet's equator
I am using JavaScript and WebGL for a game which rotates a spaceship around a 3D planet. Below is the code for rotating a sphere spaceship and sphere planet. I looked over your camera code and now it ...
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Trying to understand proper naming of transformations and coordinate systems
So far in my code I only dealt with transform matrices that I fed to OpenGL (the 4x4 float matrices), and had a class that was used to do transformations on the CPU side and generate the OpenGL ...
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Is there a way to figure out in which quad I am in fragment shader?
In my openGL project I draw a lot of quads (composed from 2 triangles) - for sake of example let's say quad 0,1,2 and 3. I process them in single pass. I do transform them with projection view matrix ...
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2d zooming function using transformation matrix
I'm trying to create a sort of "graphing calculator coordinate system" where you can zoom into a point by scrolling with the mouse wheel. I'm using javafx's transformation matrices (Affines) ...
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Rotation matrix for a model where the forward axis is not +X
I'm trying to convert a normalized unit vector, representing an entity heading, into a rotation matrix for rendering.
The problem is that I'm using an (apparently) unusual forward vector for my ...
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Obj file vertex coordinates to new coordinate space
I am trying to convert the vertex positions in my obj file to a new coordinate system. I understand I need to multiply each vertex with the transformation matrix, however I am trying to figure out the ...
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Calculating view matrix from rotation, elevation and location
I have the rotation(A), elevation(B) and location(C) of a camera in a left handed 3d space. +...
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Difference between World matrix and Model matrix?
My current understanding of the Model matrix is that it is per object and stores the transformation, rotation, and scale of the object in local object space.
What I'm not sure about, is that whether ...
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What are the pros and cons to using Transform{position, scale, rotation} over Matrix (3x4)?
I'm using Transform in a certain case where I want extracting/changing/preserving the components {position, scale, rotation} to be straightforward - I guess that is a benefit. But when it comes to ...
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Matrix math in cascade shadow mapping
I am implementing cascade shadow mapping algorithm and currently stuck with matrix transformations - my AABBs, when projected in light space are pointing in the direction opposite to the light:
I was ...
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Drawing OpenGL camera frustum
I am trying to display camera frustum in my OpenGL application. I calculate the vertices of the frustum pyramid using reverse projection from screen space to world space. The camera uses perspective ...
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How do I make 2D Camera Matrix with zoom?
I trying to understand how to make a 2D Camera Matrix. The problem now is when I zoom the world shifts horizontally.
The Camera need to zoom on the current Position.
...
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Scene graph with camera
I need help with a little problem in my project, in which I have a scene graph with the intented camera like this:
MovementNode
Camera Node
Mesh Object
My problem is that I have the propagation of ...
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How to rotate multi-tile structure on grid?
I need to be able to place structures in my game that span multiple tiles and can also be rotated.
My idea on how to solve this would be to use 2D arrays that hold data about the structure.
EXAMPLE: (...
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