I'm studying loading bones and animations data in fbx file by assimp library.

I'm looking into assimp tutorial which is based on openGL while I'm doing this with dx11.

In that tutorial, I have to understand his system which is not easy for me.

I just wanted to extracts the information not how to use it.

so what I need is...

1.Bone ids and weights per vertex

2. Bone data which is

Toroot matrix, offsetmatrix,index of it and hierarchy information like who's your daddy.

3. animation data which is

time , Scale,Rotation,Tranform vectors

I saw assimp documentation. It says 

this mean that matrix is toparent matrix?(if that node is root's son then it's gonna be toroot matrix and if it is the rootnode then it's identity matrix right?)

mTranformation inverse matrix is offsetmarix right?(tochild matrix)

the transformation relative to the world  is world matrix right?

does 'relative to' means going that space . I mean local to world matrix is the transformation relative to the world 

I'm having problem with understanding english 

help me plz and little bit of tip for extracting data from fbx by assimp

thank you for reading terrible english

In this context, "relative to" means that the space it transforms from is the one mentioned, the space of the node's parent.

For the root node, that is the object space. For a child node, it's the space of the parent.

It's a bit unfortunate, but the "to" in this usage isn't a direction like in "from/to".

"Relative to" is sort of like saying "From" in this case.  The key word is "relative" not the "to" part.  Ignore the word "to".

A transformation "relative to the parent" means you start from the parent's transform, then apply your transform.  This way if the parent moves, everything that is relative to it will move with it.  For example, your hand moves relative to your arm, which is relative to your shoulder, which is relative to your torso, etc.