Feature Request - Passive Vertice

I don’t know if this is possible/practical to code, but I have an idea:

Subdivide a plane once, giving you 4 inner edges in a + shape. Say you select one of the vertices and set it to passive. When you lift a corner on that side, the passive edge goes with as though it isn’t there, as though the plane wasn’t subdivided. In other words, the vertice didn’t act as the end point for deformation, the other corner is.

Pic:


This would be helpful in rigging, where you want stretching between two points, without fussing with constraints. This idea came up when I was thinking about rigging the pectoral muscle to the upper-arm. You want a straight line maintained, but it’s tricky with subdivisions.

If this already exists, let me know. I’m not a heavy Blender user (no time).

— K

Couldn’t you use an ngon instead?

I did a quick google on Ngons and they don’t appear to be what I’m after, unless those pages showed only one application…

The description seems vague to me. How do you define what the “start” and "end vertices would be? How should it behave when you set one vertex of a cube as passive and move one that sits next to it? What about cases with multiple “passive” vertices that may or may not be in line with each other?

Here’s a screenshot of what I meant(excuse the Ui glitch with screenshots):


Is your passive vertex idea truly the way to do this? What you are trying to do is in some sense a variation of proportional editing. I usually do what you do in the screenshot by shearing, but that has the downside that the absolute position and orientation of the object matters. Isn’t generalizing the shear operation the way to go? Or do you have examples where that wouldn’t solve your problem?

You have not conveyed the usefulness of this idea. The subdivision surface modifier produces vertices that are ‘virtual’ in that you can’t edit them and they do not influence the movement of the ‘real’ vertices, and Ngons create polygons without a center point (as Shadowlich’s illustration shows).

Think of a grid of quads instead of just one. Which points are the ‘centers’? For any set of 9 points in a 3 x 3 array the ‘center’ vert is the corner vert of another grid.

Look this addon :wink: Ngons are bad for modeling !

Hey, all the documentation is in Polish but the illustrations are so good I think I know what it is. Anyway, 1. This is part of Gstretch function in LoopTools, although can’t hurt to have another way to do it, and 2. I don’t think this is going to help the poor guy who started this although I can see how it does some of what he wants…

I can’t speak for him, but I think the tool may be more useful if it was all done with a single operation where every selected vertex but the active one gets treated automatically as ‘passive’ (just for that operation). The risk of having to mess with another flag may be more complexity to the workflow and that you will need to track and remember to un-mark the vertices depending on the operation.

How is that different from proportional editing…

Perhaps if you wanted to simultaneously alter the position of vertices in a line without affecting anything else near the selection (proportional editing in Kerric’s case given a long enough line and a large enough place will also affect many other vertices further along on the Y-axis).

Indeed,it is not quite proportional editing, but proportional editing that works only one selected verteces. What if we have an operation that allows you to move the last element in you selection and move the other elements proportionally? That could actually be quite useful.

No n-gons are bad for modeling or more correctly it depends on what you are doing and where you are in your modeling stage. for objects that are not use catmull subdivision I don’t see why you wouldn’t use ngon even for sub-d modeling the are not always problematic I often get more issues from high valency vertices than n-gons I could post a smoothed model and I doubt anyone could tell me where the are n-gons.

For organic modeling I often use n-gons and triangles during the modeling phase your model carry’s no poles and you can which can be helpful in manipulating edge loops I make it all quad when I finish but that is because of deformation.

To the o.p I don’t know where else you want to use a passive vertex but for that first post I think setting the pivot to 3d cursor and snapping on the buttom vertex and than rotating would work plus ‘g’ ‘g’ for vertex slide could be handy as well.

Sorry, but n-gons are bad for everything. If you export your model, not sur it will be good in other applications.
For a non subdivised model, perhaps we can letsome n-gons, but it’s not pro, and when I work with someone who let a lot of n-gons, I really hate that.

Proportional editing works only for unhidden vertices. Select the desired edges and use Hide Unselected.

I’m not sure if you thought the same thing, but now I’m thinking that instead of a passive vertex idea, we should have a mode for proportional editing that only affects what is selected and uses the active element as the center.

This would have a clear advantage over this idea as it would work for all selection modes as well as non-mesh objects. You can even have such a thing for working in object mode as well, so I now think that this is the way that should be done when it comes to this type of editing.

That is kind off what I thought. I haven’t that about how one would in practice use this mode, but something like it would be useful. If it would work more generally, as on object as you suggest, and with other operation than grab (for instance also scale), that could make it all the more usefull. I don’t know enough about the anatomy of blender to see whether these thing could easily be wrapped jn a common framework.

I suppose setting a vertice to be affected in a proportional-editing like way would be virtually the same thing. This would save labor in rigging, instead of trying to paint a gradient, it could be more about control points.

This thread is driving me nuts. Vertice isn’t a word. :mad: Stop it.