Saturday, July 13, 2013

Global vs. Gimbal. Let's Discuss!

So I took a look at Spladoum's Big Sister posepack on MTS and read that she had used a tip from another user but she didn't give the tip and she didn't give a location. Well, I dug around and found the tip. It's about changing a single setting in blender to get a better rotation on joints and bones in Blender. Let's take a look and compare shall we?


Before we get started I have to say that early on I found out that I had to have my own personal Order of Operations to make posing easier for myself. And if I messed up on that order, sometimes I just had to scrap stuff and start over. My own PEMDAS (if you will. *giggles) Was face, fingers, hand, waist down, waist up, head. And when I say waist down I mean I started at the waist, then posed hips, then knees, then ankles, then toes with minor tweaks in between of prior posed joints until it all aligned and looked right. Waist up is the same. Waist, back, Spine 2, the clavicles, shoulders, elbows, wrists, fingers, neck, head with tweaks in between to distribute rotations and movements evenly.




Now then, this is a pose I made on the laptop and I'm wanting to check things with it because the laptop didn't have the textures and I was working in solid mode only. The problem was I needed the eyes to move but the head was tilted. Using this tip I moved the eyes in perfect alignment and didn't need to fiddle with moving the head (since on the laptop Fred had no hair his hand is only lightly touching the scalp- as I want. But I know if I move head or hand I'm going to lose that position.) But now getting the eyes to move right would be tricky since one eye is lower than the other.

In our above example I have Fred's shoulder selected even though I have hidden the bones. Right now my Blender is in Global mode. Take a peek in the red box and you can see that we are in Global for yourself. But even the shoulder is tilted and moving along a pure x, y, or z axis is not going to be natural looking. You'd have to rotate along multiple axes to get a natural movement to untwist his shoulder. So I'm going to click on the word Global and from the menu that pops up I'm going to switch to Gimbal.





Look in the red box and you can see that I've made the switch. But look at my axis alignment! It's no longer along true x, y, z lines. It's alighted the axes with the tilt of the shoulder to get a movement that's along the lines of the musculature you've created. So if I were to make a follow pose of this one swinging his arm down would now be much easier and natural looking. Or if you're working on tweaking a face you can rotate and move your elements (joints and bones) along an axis that aligns with where that element is.

How I did it with the eyes is I rotated Fred's right eye around the z axis first (in Gimbal mode) 12 degrees, then along the x axis 2. Then I selected the left eye and rotated it around the z axis again 12 degrees, but only 1 along the x due to the position of the eyelid. If I had attempted that in Global mode I would not have had such an easy time on the x axis rotation since Fred's head is tipped.




This is Fred's original eye position. Using Gimbal mode helped keep his eye rotation aligned even though his head is tipped.




Also, though you cannot see it, I had forgotten to soften Fred's right hand and fingers but didn't want to move it so that it was perfectly straight out just to pose the fingers and get them correct.


Alrighty. Here I had forgotten to do anything with Fred's hand. He's worried here. His hand should be a little more tense than it is. The thumb needs to be rotated forward so that the nail is sideways, the last joint on the pinky isn't bent to make a crooked pinky, the fingers have no bend at all and the lowest knuckle doesn't turn the fingers toward each other to make the palm curve. But I'm in global and if I'm still in global it's a mess to make all those rotations without accidentally 'breaking' a joint. I'd be constantly moving my view and fiddling around with 'r+x,z,y'.




This is what I used to do to get the joints in a position where I could work with them if I'd forgotten to do it earlier. And when I would finally get the fingers right then I'd have to untwist that wrist with hopes it would go back to normal.




In Gimbal I was able to leave the hand where it was and still get the hand to show some stress and rigidity naturally without too much flex and I didn't have to move the wrist grotesquely to do it.


Give it a try! It really frees up tweaking. However, after playing with it for a while on several poses, I personally would recommend doing your actual pose in Global mode first saving the Gimbal for tweaking only as joints seem to twist a little more easily out of place.

If anyone would like to share their own experiences between the two I'd love to hear it! Leave your thoughts in the comments section and lets all help each other be better posers! (Wow that sounds old school, doesn't it? Posers. lol)

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