Current GUI scheme is kinda old, and some users have been suggesting we should make a re-design on the GUI layout.
I've been considering to redesign the GUI layout to make it more intuitive and aesthestically pleasing.
But before I get it done, you still need to work with the current one :D
======= Current Main GUI Layout =======
This GUI will be shown when you start the bone-editor; Now let's examine each of them.
"C": Camera reset. This one will set the editor focus on currently selected joint, so you could use orbit and zoom-in/out around that point.
There're four main camera control modes in Unity: FPS, Pan, Orbit, Zoom
FPS is the most familiar mode to most Unity users; under this mode, you hold "RMB" + "WSADQE" to navigate your camera around the scene;
Pan is used by hold "MMB" and move around, it's kinda like FPS mode with only without forward/backward movement;
Orbit is a very useful function when working with models, you could use "Alt + LMB" to orbit around current focus position, the camera will look at the focus point and maintain the distance;
Zoom is...well zoom, scroll the "MMB" or use "Alt+RMB" to zoom in/out on the current focus position;
"R": Reset pose. This function is very useful, it reset the current skinned-mesh to the default pose on the prefab (usually the T-pose / natural-pose, depending on how the modeller does the work)
"G": Pose Manager. It manages the static poses, you could save/load/apply pose to help making animations. This feature needs detailed explanation, we will do it in an individual page;
"I": Bindpose fixer. Not useful, scheduled to be removed in the next major update;
"P": Change orientation. Click this button or click hotkey 'P' will trigger the change of handle orientation. It cycles among the three of "Global/Parent/Local". Hotkey 'P' will only cycle between "Global/Local" as these two are the more useful in usual cases.
"B": Display hidden bones. Unity hides those bones that have no vertices bound to by default. You could toggle this option to change that.
This option is also very useful when you work with multi-mesh models, it could display all the joints together （even some other non-joint object, such handguns/accessory/etc), not only the bones related to current SMR.
"W": Display the wireframe. Unity by default displays the wireframe of model when selected. It's kind of distracting when edit joints, so we turn it off by default.
"V": Display the vertices marker. Turning on this will display all the vertices with color indicating the weight of current bone.
"H": Hotkey list. display a list of hotkeys.
"M": Mirror edit. This feature will be revised later. So leave it alone for now.
"IK": Toggle IK mode. You could toggle between FK & IK mode with this button or hotkey "backquote". IK needs an individual page to explain later.