I’ve been reading/hearing in a lot of articles and tutorials that there should be a root joint to a character’s skeleton placed at the origin. (the alternative would be for the pelvis to be the root). But I also have come across many assets and projects that seem to be pretty professional that do not follow this “rule”. So I’m wondering why people do that, what are the benefits? I personally have not run into any problems not doing that. Because when you import an fbx, Unity automatically creates a root group under which the contents of the fbx are in. So that seems to accomplish the same purpose.
Most rigs have their root joint at the origin because it’s convenient and aids in clarity. For humans, most of what they do is relative to the ground, and the origin is on the ground. In the game physics, the support point is also at the bottom of the character. For flying objects, they mostly rotate about their center, and usually are built with their center at the origin. Also, when root motion is enabled, the animation for the root node is often similar to the pelvis, but not identical to it. Having the root node and controls at the origin helps give animators a clear indication that they shouldn’t just blindly copy pelvis curves onto the root.