Ikas Blender 3D ( 7 - Various tricks )

Introduction - Armature and Mesh - First animation - A little more - Constraints - Weight - Weight paint

Various tricks:
This page, which could possibly be expanded if you let me know of any tricks or tips concerning the use of armatures, constraints and weight paint that you discover in the vast quantity of information which did not find its way into the preceding pages; which I wanted to limit to the bare minimum of contents so as not to frighten the neophyte and preserve an acceptable legibility.

A window too often ignored: the information window which opens with the window selection button framed in red in the opposite image or by lowering the border in the upper part of the screen when the default setup of Blender is launched. You will find two new buttons there which are very useful for animation. KeyAC and KeyOB.
KeyAC relates only to the armatures and the curves of the new animation system whereas KeyOB is limited to objects and the standard IPO curves. When these buttons are engaged, any transformation performed ( Displacement, rotation, changes to the scale ) is automatically registered as a key in the Ipo window, which avoids having to continually press the ' i ' (Insert) key. Note: The transformation cancelation operations ( ALT+G, ALT+R, ALT+S ) are not automatically taken into account by these options. To remedy this, after having cancelled one or several of the transformations, all that is required is to make a ' empty operation ' on the object ( Select it, choose the transformation that is wanted and press 'Enter' immediately without changing anything ).

Centering an armature: In the edit window for the 'bones', the 'Centre New' option is cruelly absent. Successive manipulations to the armature can sometimes place its center in an undesired position. In this case, you can always switch to 'edit' mode ( TAB ) select all ( A ) and move the whole asembly until it is positioned correctly, but attention! - If objects are already parented with the armature, or if the latter is subjected to constraints related to external objects ( Emptys or others ), you will have a nasty surprise when you quit 'Edit' mode. When in doubt, always backup first and even better: Ensure that you have the armature correctly centered and positioned before parenting any objects to it or animating it.
The case for OR: In case you haven't realized it yet, you can assign different objects, as many as you want with an armature ( Then they are parented with the 'bones' or the armature ). Now, you no longer have any excuses to be unaware of this detail.
The Animation Bug: The bug having been identified and announced as corrected, it should be mentioned that these lines should only concern 2.20. This bug relates to the parenting of objects to the armature. When you parent an object with the option 'bone' which assigns the entire object to the selected 'bone', as long as you do not launch the rendered animation, everything seems well, but at the time of rendering, one notes with despair that the objects parented in this manner remain motionless. To circumvent this obstacle, never use the 'bone' option when parenting to the armature, instead use the standard option 'armature' and then assign all of the object's vertices to the 'bone' concerned.
Download the file bug.zip and create a rendered animation to see an example.
The Order of the Constraints: When working with a sequence of complex constraints, it is important to note that the order of the constraints is critical, otherwise the results may sometimes be surprising. The "apparent" application of the constraints is done from the bottom to the top. The image shows you an example of a bone which is initially subjected to a constraint of type 'Track To' plus a second one of type 'IK Solver'. Reversing the order of these constraints will give a very different ( and incorrect ) result. To move a constraint in the list, it is initially necessary to minimize the dialog box, which you want to move, by clicking on the orange arrow and then left clicking on its title bar to bring up a small pop-up menu with the choices ' Move up/Move down' which will move the constraint in the required direction.
Note: There are incompatible constraints beween the 4 types of constraints. For example 'Track To' and 'Copy Rotation' which modify one and the other orientation of the object. In this case, only the constraint located lower in the list, will be taken into account.