please do not edit your post for your questions, i'm not notified of it, just post another message. in this case, I've seen your edit accidentally
a question first: why are you trying to make your own 3D editor instead of using a well known one?
1)
Could you please explain what variables the MeshData constructor requires? It is not explained in the JavaDocs. How would you generate this information from the World or the World objects? Or is that not possible?
those arguments are explained in Object[] constructor, have a look at the "see also" link.
2)
To contruct Skeleton, we need to create a Joint array. Could you please explain what is expected for the first argument in the Joint constructor (Matrix)?
that's inverse bind pose of joint (bone) as the documents say. that's a fundemental thing in skeletal animation, google for it
3)
As far as I understand the SkeletonPose is a wrapper for Skeleton. I thought I need to define one SkeletonPose for each key frame of the animation (while using the same Skeleton). But that wouldn't make sense with what I gathered below. Could you please explain what SkeletonPose is used for? Is it just a wrapper for "internal things"?
SkeletonPose is not really a wrapper. It's a pose of skeleton as its name suggests. animation puts SkeletonPose into a certain position and that's used to deform mesh (apply animation) accordingly. have a look at SkinClip.applyTo(..) and Animated3D.applySkeletonPose(). Animated3D.animateSkin(..) does both of them behind the scenes.
4)
What do the parameters look like for the SkinData? I can think of multiple ways and would prefere not to use try and error
a vertex can be deformed by up to 4 joints and each joint has a weight for this deformation. ie: how much vertex will be effected from joint's translation and rotation. SkinData defines this: first index in both arguments is vertex index. second index define joint weight and corresponding joint index.
5)
All right, let's assume I have created the Animated3D. As I understand I just need to create this once. If I have different animations (e.g. walking, jumping, crawling, etc), I just attach different SkinClipSequence to the Animated3D. Can I attach several at once and then change between them?
In the java doc it is written that Animated3D is an Object3D. So I don't need to add anything else to the world to display it? But then how do I color it or add textures?
I have currently a lot of objects with different texture in the world that I want to animate as a whole. Can I make things simpler with using AnimatedGroup?
each SkinClip is a different animation (walk, jump etc) and we put many SkinClip's into a SkinClipSequence. so yes, you can attach several animations at once.
you can set texture via to Animated3D.settexture(..) method (inherited from Object3D). there is no setColor method.
AnimatedGroup is meant to pull multi-mesh objects into a single entity. yes, you can use it for your complete scene.
6)
Just making sure I understand correctly: I define a JointChannel for each Joint. This defines how the joint changes from state A to state B. And those JointChannel are then summarized in the SkinClip, which defines the transition from one key frame to another. These transitions are summerized in SkinClipSequence (an animation, e.g. "attack", for our object), which itself can be attached to the Animated3D object.
not really. JointChannel defines transitions from keyframe to another for a single joint. SkinClip pulls several JointChannel's together and defines a single animation for all of the joints (whole skeleton). and finally SkinClipSequence is one or more animations (SkinClip's)
7)
When I'm done with all these things, would I be able to export everything easily to a file (Collada or Ogre)?
Bones does not include any code for exporting. You need to write your own exporter, or use code of an existing one
I'm still learning a lot about these things, so feel free to direct me to any additional material that you think might be helpful!
skeletal animation is a complex subject, especially the calculations. prepare yourself to hit your head to walls
but again, why are you doing this instead of using a well known 3D editor?