FAQ Database Discussion Community

OpenGL fixed coordinate transformations

opengl,coordinate-systems,rotational-matrices
Was just trying to do some rendering with OpenGL and I happened to think about that: how would you run transformations in a fixed coordinate system. In other words, if you rotate an object around one axis you will see that the others are going to rotate too? Therefore, following...

Sparse Rotation Matrix Python SciPy

python,numpy,scipy,sparse-matrix,rotational-matrices
I'm working with quite large rotation matrices, which have the inherent property to have a large number of zeros. In order to reduce memory use and possibly reduce computation cost when multiplying these rotation matrices with other matrices/vectors, I would like to use a sparse matrix data structure. I have...

Android Rotation Vector and Rotation Matrix

android,opengl-es,linear-algebra,android-sensors,rotational-matrices
So I previously asked a question more about what ind of sensor to use for the application I'm building. After some research I know now that it's the rotation vector that I want to use for I want to be able to move a virtual cube on my tablet according...

Separating axis theorem: rotation around center of mass

c++,math,rotation,rotational-matrices,separating-axis-theorem
The problem is in Polygon::FindAxisLeastPenetration: double Polygon::FindAxisLeastPenetration(unsigned int *faceIndex, const Polygon &polygonA, const Polygon &polygonB) const { double bestDistance = -std::numeric_limits<double>::infinity(); unsigned int bestIndex; for (unsigned int i = 0; i < polygonA.points.size(); i++) { Vector2D n = polygonA.normals[i]; Vector2D nw = polygonA.rotationMatrix * n; //ROTATION Matrix22 buT = polygonB.rotationMatrix.Transposed();...

Fast Quaternion-Vector Multiplication with other Transformation Matrices

math,matrix,3d,quaternions,rotational-matrices
I am currently trying to find an equivalent for the following equation: vec_res = inverse(VM) * (q * (VM * vec_input) * conjugate(q)) where VM is a standard view matrix , q is a normalized quaternion, and vec_input a vector. In the form: vec_res = A * vec_input; or vec_res...

How to rotate objects in OpenGL relative to local or global axes

c#,opengl,quaternions,rotational-matrices,sharpgl
I'm asking a question that has been asked a million times before, but I still haven't found a good answer after going through these and also resorting to other sites: How to rotate a graphic over global axes, and not to local axes? rotating objects in opengl How to rotate...

Finding the right kind of Android sensors and using them

android,opengl-es,android-sensors,rotational-matrices,sensormanager
I've tried to search both on google and here the solution to my problem and I don't think it has been asked before (or may I be using the wrong words in my search? ^^') Anyway, this is what I want to have: a OpenGL surface view (showing a cube...