The big issue with plotting maps is that the spherical surface of the Earth cannot be conveniently converted into a flat representation. There are a bunch of different projections that attempt to resolve this. Mercator is one of the simplest: it assumes that lines of equal latitude are parallel horizontals, while lines of equal longitude … Read more
3 Solutions to recover view space position in perspective projection The projection matrix describes the mapping from 3D points of a scene, to 2D points of the viewport. It transforms from view (eye) space to the clip space, and the coordinates in the clip space are transformed to the normalized device coordinates (NDC) by dividing … Read more
Now, my question is for the elbow. Why is there a translation forward on the x-axis both before and after the rotate? If you want to imagine how the matrix operations change the model, then you need to “read” the operations in the reverse order. This is, because the current matrix of the matrix stack … Read more
To rotate use transform=”rotate(deg, cx, cy)”, where deg is the degree you want to rotate and (cx, cy) define the centre of rotation. For scaling/resizing, you have to translate by (-cx, -cy), then scale and then translate back to (cx, cy). You can do this with a matrix transform: transform=”matrix(sx, 0, 0, sy, cx-sx*cx, cy-sy*cy)” … Read more
In a rendering, each mesh of the scene usually is transformed by the model matrix, the view matrix and the projection matrix. Finally the projected scene is mapped to the viewport. Model coordinates (Object coordinates) The model space is the local space, where within a mesh is defined. The vertex coordinates are defined in model … Read more