How does this animation work?

Question

This project "Locomotion Skills for Simulated Quadrupeds" creates an animation for the dog model in the program. However if you go into the project's files the dog's skeleton is made of individual obj files for each bone. How were the bones loaded into the program to make the complete animation? It's as if the position of the obj's were attached to... the vector I guess? Can anyone elaborate a little more?

My reasoning for this is because I want to replicate it, create a model (to be animated) out of separate model files. I guess my question is how make one character out of several separate model files? Thanks

Answer 1

Animation is a very complex part of 3D rendering, and I recommend you read this first. But here's what's going on in a nutshell:

In order to animate a mesh you need to define a set of 'bones' for the animation, and it's the bones that are being rotated and translated according to the animation. The model that's being displayed will have it's vertices linked to one or more bones which will determine their transformations.

The separate obj files you're seeing in the project are each linked to one of the bones, so that when the program is running you can clearly see the movement of each bone. They simply apply the world transform of each bone to the mesh associated with that bone.