Constraining a null with enforcement percentages

[JohnnyB]

I'm a boot (see johnnyb's bootcamp). I'm working on making a pixar lamp hop and Rob pointed out that the lamp's center of gravity is somewhere between the light and the base (see his comments below). He provided an excellent tutorial of the problem (see my bootcamp's last page).

 

 

"It wouldn't be too hard to "translate to" constrain a null to both the light and the base. Set the enforcements to 50/50 or 60/40 or whatever and it would float at an appropriate midpoint.

 

Not that you would be keyframing that null; it would just be a visual guide of where your c.o.g. was at any moment.

 

That pixar-style lamp is probably one of the few characters that that could be rigged on. Most have shapes too complex to find the c.o.g. so easily. Hmmm...."

 

I'm not sure that I even know what a null is nor how to set a 50/50 or 60/40 enforcement. Clueless!

 

So Rob suggested that it would be a good topic for the rigging forum. Am I in the right place? Can someone point me to a thread on that subject or explain the terms?

 

Thank you!

Johnnyb

[3DArtZ]

Hey, I think that should be pretty easy.

But since I don't know what the lamp looks like, here is a basic suggestion, if I'm reading what you say correctly.

 

I wouls place 2 bones in the model. One at the base of the lamp, the other at the location that would be at the location Robcat mentioned.

Then add a null.

in an action window, or pose window, right click on the null and assign a new translate to constriant to the base bone. then do this process again and translate it to the other bone.

the null will find the exact middle location between the 2 bones.

 

Mike Fitz

www.3dartz.com

[JohnnyB]

Hey, I think that should be pretty easy.

But since I don't know what the lamp looks like, here is a basic suggestion, if I'm reading what you say correctly.

 

I wouls place 2 bones in the model. One at the base of the lamp, the other at the location that would be at the location Robcat mentioned.

Then add a null.

in an action window, or pose window, right click on the null and assign a new translate to constriant to the base bone. then do this process again and translate it to the other bone.

the null will find the exact middle location between the 2 bones.

 

Mike Fitz

www.3dartz.com

 

What is a null?

[3DArtZ]

While in "Bones" mode in the modelling window, right click, and navigate the drop down menu

till you see add new null.

It's basically a Bone that you can not assign any control points to.

Its used as targets to aim at, targets to grab for pertinant points on your rig, like as a foot target, hand target, eye targets. Stuff like that.

 

Mike Fitz

www.3dartz.com

[JohnnyB]

While in "Bones" mode in the modelling window, right click, and navigate the drop down menu

till you see add new null.

It's basically a Bone that you can not assign any control points to.

Its used as targets to aim at, targets to grab for pertinant points on your rig, like as a foot target, hand target, eye targets. Stuff like that.

 

Mike Fitz

www.3dartz.com

 

Thank you Mike! I think I can work from here.

 

JohnnyB

[Fuchur]

A null is most often used as a placeholder for Constraint-Targets.

If you want to let a character look in a certain direction for example, it is wise to use AimAt-Constraints for the EyeBall-Bones with a Null as Target.

 

A null behaves like a Bone would do, but it looks different and can be better sorted out if you are using many bones in a project.

 

Furthermore a Null-Object is a own object, so you dont have to make it in a modeling-window but you can add one in a chereography -> Different to a "normal" bone.

 

That can be usefull, if you want to let to characters look at the same point/direction, etc.

Another exception to a normal bone is, that you cant assign CPs to a Null-object, if I am not wrong.

 

*Fuchur*