Partial enforcement of some constraints

[ArgleBargle]

Here's the box I put myself into: I have a character looking at another and eye focus is manually placed on the 2nd character. The camera then starts to move in on the first character for a close up and character turns to address the viewer. The camera is still in motion as the character looks at it. I figured I'd be clever and translate eye-focus to the camera. However, so the eyes would move somewhat naturally, I'd go to the channel for enforcing translation and changed the type from hold to linear. Well, sure enough, it sorta worked... but not totally as I expected. As soon as enforcement rose above 0%, the eye focus immediately leaped to a point just a bit in front of the character's face, then made it's transition from there to the camera.

 

Am I to understand that less than 100% enforcement of a bone/null position is always going to be relative to the bone's original position, not relative to any subesequent positioning in an action?

[J.Bruce]

I'm not sure if I understand exactly what's happening. Is like in Ferris Bueler's Day Off when he would look at someone then look at the camera?

 

If so there are a couple of solutions I can think of off the top of my head:

 

1. Add constraint to character (the one being talked to) [character]. Add another (completely new) constraint to the camera [camera]. Start with the [character] at 100% and [camera] at 0% then go to where you want the character to look at the camera and set [camera] at 100% and [character] at 0%. Change interpolation method to something other than hold. What should happen now is that the enforcement of the [character] constraint will degrade as the [camera] constraints becomes greater. Further, it will happen in such a way that [character] will be at 90% when [camera] is at 10%. This should stabilize any funkyness.

 

2. Build an eye rig. Then move the "focus" null.

 

That should work. If not let me know.

 

J

[ArgleBargle]

I'm not sure if I understand exactly what's happening. Is like in Ferris Bueler's Day Off when he would look at someone then look at the camera?

 

Yeah... whatsit called in theatrical terms? An "aside?" Essentially that, but it's a children's educational video. The child is very often addressed in the video.

 

If so there are a couple of solutions I can think of off the top of my head:

 

1. Add constraint to character (the one being talked to) [character]. Add another (completely new) constraint to the camera [camera]. Start with the [character] at 100% and [camera] at 0% then go to where you want the character to look at the camera and set [camera] at 100% and [character] at 0%. Change interpolation method to something other than hold. What should happen now is that the enforcement of the [character] constraint will degrade as the [camera] constraints becomes greater. Further, it will happen in such a way that [character] will be at 90% when [camera] is at 10%. This should stabilize any funkyness.

 

2. Build an eye rig. Then move the "focus" null.

 

That should work. If not let me know.

 

J

That's precisely the thing being moved: the focus null. It's been a while since since I looked at how I built my characters, so I did my own follow-up to my question. Enforcement for the position of the null is relative to its original position in the figure. While I suspect I could do what you suggested (or my other idea below) I punted and just moved the focus null to intercept the moving camera, then constrained it to the camera at that moment in time. It looked good and now I'm happy.

 

My other thought, and one I may follow from this point out, is to constrain all the focus nulls to either parts on other objects, or strategically placed nulls in the chor. Then do like you outline above.

 

I originally avoided this technique for a different reason. I tried sliding constraints to move the camera from one location to another. Considering this involves camera orientation as well, it was a catastrophe and I abandoned the method. I guess I shouldn't have thrown the baby out with the bathwater.

[robcat2075]

As soon as enforcement rose above 0%, the eye focus immediately leaped to a point just a bit in front of the character's face, then made it's transition from there to the camera.

Without seeing the project, it sounds like the enforcement has been changed at the wrong time.

 

Am I to understand that less than 100% enforcement of a bone/null position is always going to be relative to the bone's original position, not relative to any subesequent positioning in an action?

No, some other complication is at work.

[J.Bruce]

Yeah... whatsit called in theatrical terms? An "aside?" Essentially that, but it's a children's educational video. The child is very often addressed in the video.

 

I think it's also referred to as breaking the fourth dimension or something weird like that.

 

That's precisely the thing being moved: the focus null. It's been a while since since I looked at how I built my characters, so I did my own follow-up to my question. Enforcement for the position of the null is relative to its original position in the figure. While I suspect I could do what you suggested (or my other idea below) I punted and just moved the focus null to intercept the moving camera, then constrained it to the camera at that moment in time. It looked good and now I'm happy.

 

My other thought, and one I may follow from this point out, is to constrain all the focus nulls to either parts on other objects, or strategically placed nulls in the chor. Then do like you outline above.

 

I originally avoided this technique for a different reason. I tried sliding constraints to move the camera from one location to another. Considering this involves camera orientation as well, it was a catastrophe and I abandoned the method. I guess I shouldn't have thrown the baby out with the bathwater.

 

If you have the focus null I wouldn't even worry about constraints I'd just put it there. Because when you constrain it to something you have less ease of control. Like subtle movement and whatnot. But, yeah just like rob said without seeing a render or a project file it's difficult to truly tell what's going on.

 

J

[luckbat]

Yeah... whatsit called in theatrical terms? An "aside?"

Yes.

An "aside" is a technique used in a dramatic performance whereby the actor will step 'aside' from the action and deliver a soliloquy or an asinine remark to the audience which is assumed to be unheard by the other characters on stage.

[ArgleBargle]

As soon as enforcement rose above 0%, the eye focus immediately leaped to a point just a bit in front of the character's face, then made it's transition from there to the camera.

Without seeing the project, it sounds like the enforcement has been changed at the wrong time.

 

Am I to understand that less than 100% enforcement of a bone/null position is always going to be relative to the bone's original position, not relative to any subesequent positioning in an action?

No, some other complication is at work.

 

Hmm, the project where I found the issue is pretty big, so I made a tiny one with Eddie and a sphere. It's attached.

 

Frame 0: Focus left where it originally starts with the model; the sphere starts to follow the path.

Frame 15: Focus manually moved to Eddie's lower left.

Frame 30: To his upper right and hold

Frame 40: Constrain focus to the sphere, but enforce at 0%

Frame 41: bad juju. (See next paragraph.)

Frame 45: Enforcement at 100%. Focus is on sphere.

 

The kicker is frame 41. At that point, the focus has leapt to a point about 20% from the model's original focus location and the target.

 

I may or may not be doing this right, but at least I'm reproducing it consistently.

focusconstraint.zip