# The matrix transform

1. Jun 23, 2012

### nsorter

1. The problem statement, all variables and given/known data

How to find the transformation matrix of Object B in world coordinates, when you know the transformation matrix of Object A in world coordinates and the matrix of Object B in Object A's
local coordinates

2. Jun 23, 2012

### HallsofIvy

What do you mean by "A's local coordinates"?

3. Jun 23, 2012

### nsorter

there are "World" coordinates and "Local" coordinates

"Local" - object coordinates

Object B is in another(Object A's) local coordinates

Imagine Solar system

It's center is the Sun(x,y,z is 0,0,0) and planets are moving around it's World coordinates. Earth has it's local coordinates and Moon moves around Earth in it's local coordinates

We know Object B's (the Moon) position in Local coordinates(As if the Earth is the center of the Univers(0,0,0) but we don't know the World coordinates where the center is the Sun).
And we know Object A's World transformation matrix

How can I get the matrix transformation of "the Moon" in World coordinates, when we know it's position in local (relative to Earth) coordinates, and transformation matrix of Object A in World coordinates.