I’ve created a simple 3D human model with bones and a mesh and everything works fine.
The problem arises because I would like to have a specific orientation on the bone’s axis, not the one that blender assumes. It seems that blender always make +Y as the direction of the bone, thus if I extrude one bone to the right I’ll get a rotation in the bone’s axis with relation to the parent bone.
I’d like to have the same axis in all the bones, equal to the scene axis.
Is there a way to change each bone local axis (in the rest position)?
The Y-axis will always be Y – no matter what. To change the X and Z axis, go in edit mode and in the bone tab there is a slider called “roll” as you move it from 0 to 90 to whatever, the Xand Z axis will rotate around the Y
thanks for your answers but, as I said, I’m new to this stuff… (and using blender 2.63)
I’ve not managed to see (draw) the local axis of each joint. The only axes I see (even when changing from global to local or clicking axis box in the Display menu) don’t ever change, and are equal to the scene axis. I thought that all was working as I expected, same axis in the all bones…
The problem arises because I’m exporting the model to directx (to a .x file) and then applying rotations to its joints in irrlicht.
For the bones that point up, all work as I expected, but for the horizontal ones it the axis are rotated 90 degrees.
Maybe I can change that using roll but I’ll need to see the local axis to be sure I’m doing the right thing. How can I do it?
I’ve not managed to see (draw) the local axis of each joint.
In Pose Mode, hot key [A] will select all the bones. In Properties Window under Armature there is Display setting. Just check Axes to display bone axis.
are you turning “Axis” on in the object and/or armature tab – there are a series of checkboxes (Names, X-ray, AXES, Colors, etc) check the Axes checkbox, then you will see small coordinate systems on the tip of each bone in edit mode
The bone axes can be converted by the importer/exporter
Even though blender assumes Y+ to perform its calculations internally it should be sufficient for most users to simply draw the bones differently in the viewport.