Cineversity

Hello,
I’m experiencing a lag with my Ribbon Lips rig that I have spent the entire day trying to fix. Could you help me understand what is going on, please?

The Rig
I have a Lip Rig with the following order of operations:

1. 12 bind joints constrained to 12 “minor controllers” by PSR Constraints
2. A polygon “Ribbon” plane bound by a Skin Deformer and 5 bind joints.
3. 5 “major controllers” for the 5 bind joints, constrained by PSR Constraints.
4. 12 minor controllers clamped to a “Ribbon” polygon plane by Clamp Constraints
5. Mouth geometry bound by a Skin Deformer and the 12 bind joints

I am using a Ribbon driver to be able to get twist with falloff on all axes without flipping as is common with IK-Spline. Polygons also seem to do better in the Viewport than Splines. It’s working fine except for the final step: the mouth Skin Deformer. The file is attached.

Object Manager & Priorities
The priorities for the Constraints are all set to Expressions 0, except for the Minor Controllers, which are set to Generators 0.

Questions
1. Why do the minor controllers need to be in Generators priority?
The only generators are the Splines. I tried a version with Null Objects and there was still a lag. I was told on another forum to not use Priority: Generators 0 except in rare cases, so I put them at the bottom of the Object Manager, but they don’t work that way.

2. Is it possible that the Skin Deformer isn’t being executed at Expressions 0, but still at its default, Generators -1?
I was also told that Cinema 4D can’t change the Priority for Skin Deformers. The help manual says Skin Deformer Priority only works with Force enabled, which only works with point objects that are not polygon objects.

3. How can I fix the lag between the rig and the Mouth Geometry?
If the issue is because I need the Constraint expressions to run between the Ribbon and the Mouth Geometry’s Skin Deformers, is there a workaround? I’ve tried Loft and Extrude NURBS. The Loft NURBS allowed for twisting like the Polygon Ribbon does, but the parametric geometry was unstable…its U divisions changed when I manipulated its Splines. The Extrude NURBS provided more stable geometry, but I couldn’t twist the points of the Spline.

I’ve tried so many things. I am now coming to the community for help. Thank you.

Hi blastframe,

Nice idea with the five major handles and have minor handles for the detailed expressions.

Here is the result: (screen capture, one minute)
https://www.amazon.com/clouddrive/share/oXev7MjMsM0UvKtfnTn61BSxZ4rqwJLoxbwpjfgiCKu

How about eliminating all the stuff that causes problems and keep the functionality anyway?
In other words, get rid of the Ribbon altogether, and use the information that you have already without any detour.
The simple answer is given in splitting up the PSR values between two of the major handles each time.

Scene file:
https://www.amazon.com/clouddrive/share/2XudWkjpEaLQAzXKSIvINrZ8LvlrprrxxhFkIdu7iJS

Priorities. You have for example the Ribbon joints below the Final joints. Etc.
Each layer of priorities goes one time top to bottom through the object manager, then the next, the higher it gets, the more it will overwrite what was before, but also what is even higher, will not be available and taken from the frame before. Here is what you need to do:
Take a piece of paper and write all the parts down and draw a line on how the information flows. This is what I have done with this file, and it was quite an up and down. It doesn’t help if I share that. You need to get used to this. It is part of the work. It is always the flow of information, IF all is on Expression 0, then it is top to bottom. If there is one Expression 1, then this will be calculated first, independent that others with Expression 0 are above or beyond.
You have shared a five line list, but the Major was on position 3, however, they move quite some stuff from line 1 and 2, right?

Those Ribbon setups are just twice the work and not elegant at all. The translation you hope to gain from it can be done with Constraints. Avoid those Ribbon, I have no idea who suggested them, I haven’t seen them here.

I hope I sounded not critical. If so, sorry, not my intention.
The file above should work as you like to have it, with fewer parts in it.

I’m sure all the hard work of yours will pay off.

My best wishes for your project

Hi Dr. Sassi!
Thank you for the reply. I believe the scene file you sent was a video for another post. I am eager to see what you’ve created.

I do not take your advice as overly critical. It is important for me to hear what someone with more experience in Cinema 4D thinks, so it is very valuable, thank you!

Prior to reading your message, I also decided I should abandon the ribbon. It was a technique I learned with Maya in a facial rigging course on Rigging Dojo.

I did know that the Object Manager computes from top to bottom. I set all of my priorities to Expression 0 (including the Skin Deformers), but no matter where I placed the objects with Constraints in the hierarchy, it did not fix the lag. That was why I was so confused when I got the minor controls to work with Generators 0.

I’m looking forward to seeing your version! Thanks again.

Hi blastframe,

Thanks for being open to different ideas. There are more priorities in the game, for example, the joints have priorities as well. Some objects, generally speaking, have fixed Priorities and some have even split (two) priorities.

Yes, it is not that simple. Even inside of Xpresso, the sequence of how the nodes are listed in the manager will cause trouble from time to time. Hence why I take a card and try to figure out what the information flow is inside a scene.

With Priorities, you can write a scene file that has a long delay. I think I posted this one before.

The scene file is fixed, sorry, sometimes the “memory” and the browser are not in sync. I know that, and I had that trouble before, so: My Fault! So, sorry.

I’m sitting here and try a more elegant form of doing this, as we had a slipping vertices problem lately, and the setups have something in common. Since no book is available with all the right setups for Cinema 4D, I have to invent the wheel sometimes. I’m sure there are quite some Technical Directors who have a lot of solutions for that. I wish they would write the book about.

All the best

This one is based on the way you want to animate, and it is experimental. Call it brainstorming.

I believe in simplicity. But I think that a rig has to be comfortable. It is a balancing act if one does both (vs. TD and Animator).

Scene file and screen capture.

https://www.amazon.com/clouddrive/share/771W8Xhe9szt4qBE8BT1rgWT4PwACjBbxQBec1ww38W

I hope it will at least provide some ideas.

That is so cool, Dr. Sassi! :-D I love it. It’s simple and performant.

I took a look at the XPresso. How is the twist happening? I see you are adding to the Vector of the Point Position. Is the Vector somehow affecting the Matrix?

Thanks a lot for your feedback, blastframe!

The twist is bast on the second Spline, which works as a Rail.

In the Xpresso, the top part (also top in the X-Manager) placed the Spline vertices where the “stars” are.

The second part, calculated after the top part, takes the information from the Spline and transfers it to Spline.1, but it adds the “Circle” position to it.

This is all simplified. With a MoSpline this Rail could be expanded with many virtual vertices.

Anyway, back to the Ribbon, which is just a problematic way of translating information that is given already. If you have five main points in the rig and a lot of adjusters along the way for orientation, then it is perhaps more a question of how to get the information changed, so it follows your needs in the most straightforward way, straight forward, and of course all in one place with one clear priority. Math is undoubtedly here one of the main answers.

I’m exploring something at the moment,, here is a little screen capture, perhaps it pushes some new ideas. The spline rig is not ready to be posted yet. Tracer has a fixed priority, so Xpresso would be better. Etc.
The first part of the clip shows something like a spline curve is calculated. Which is an example of how some few point positions can be translated without the detour via a joint/polygon/skin detour.
https://www.amazon.com/clouddrive/share/LSVNgeroP3xPSvNNtvXAshMno8BhmGjGX6zk6GI2hcf

Cheers