Modify problems on large meshes

[Anonymous]

I am trying to Modify >Soft Transform , and while selecting faces works fine, then  optimize and smooth is also just fine, after choosing 'soft transform' through modify menu, it selects " entire mesh " which of course takes a very long time given size of mesh and complexity- , instead of selected area.

This is true no matter what mesh I use( high TRI count, 1.7 MIL ) , except 'bunny', which works as expected.

Is there anyway to go back to V 3.4 ?  I  dolwnloaded and reinstalled but same problem.

Dead in the water for now till I fix an issue , regarding a feature I use often.

THx anyone

[MagWeb · Accepted solution]

Running SoftTransform the tool expands the selection. The area added to the area selected before will be the area to be deformed. That's ok.

Now there are some special cases which are not handled by default tool settings:

Take a look at the IgnoreGroups checkbox.

If enabled FaceGroups at your object are ignored. You need to set the added (modified) area manually using the Falloff slider.

If disabled and you selected an area

1. on a "white" object without any groups the tool will act the same way as if you enabled the checkbox on a object with FaceGroups.

2. on an solid object which owns a group AND that group is an island inside a non-grouped white area : Again the same behaviour.

3. on an solid object which owns several (at least two) groups AND all but the selected group1 are neighbours of group1 the  selection will expand to the whole object. In this case you need to enable IgnoreGroups.

4. on an solid object which owns several (at least three) groups AND at least one group isn't a neighbour of group1

the selection twill expand to the neighbour groups only.

>> If IgnoreGroups is disabled the selection will expand to neighbour groups (while white isn't a group)

----

If the whole bunny is made of two groups  (and no white) and you select one group to SoftTransform, the selection will expand to the whole object too, but as it owns an open boundary and FixedBoundary is enabled SoftTransForm works the way you expect.

[Anonymous]

HI,

TY so much for the valuable information- WHEW what a  relief...appreciate explanation , and ya soon as I turned on ignoregroups, all was back to normal.

I need to much more familiarize myself with the tools options;))

ty

[Anonymous]

ONe more question on topic:

THis is not usual beahvior, not sure why it started occurring  suddenly, but while you fix works great, ty again-doing modify > soft translate wants to select ENTIRE mesh, and its huge,2MIL (small by comparison yes I"m sure), so its takine FOREVER to select entire mesh, where prior before ONLY selected area , directly around,my selection.

I looked in prefs, and ther is no option to option for way to enable it compared to tic option in modify panel.

Its taking far too long to do this, so where does this get set ?

TY!

[MagWeb]

The problem is that SoftTransform is one of the tools where the last used settings are not remembered. So it always starts with IgnoreGroups being disabled. So in the cases I mentioned above it will build some kind of "modification cage" for the entire rest of the mesh which might take eternities on huge meshes. There's nothing you can do to avoid this via some setting.

The only way is to define your groups properly before running SoftTransform. One option is to select the (second) group around and delete that grouping (via Modify/ClearFaceGroup) > You'll get the state as if IgnoreGroups were active.

Or the another is to define one or several groups around the group to be transformed which limit the "to be modified" area before:

Neighbours for SoftTransform

[MagWeb · Accepted solution]

There's also neat trick (which uses some kind of MM bug):

Before running SoftTransform run simple Transform on the selection. Do NOT move the widget but hit Accept. This creates a grouped loop of zero area faces.

Now if you run SoftTransform it will expand to that (not visible) group only. OK, your selection might disappear but as soon as you enable IgnoreGroups its here again....

[Anonymous]

TY For exaplain, good to know, and again TY for   the BUG :)))

Awesome--thx 😉

[Anonymous]

NOt a problem anymore, just more a curiosity,

Loading Bunny, and taking any part of mesh and doing soft transform, and it does not exhibit the behavior we're speaking of at this time.

Does the behavior scale based on size of mesh ,- just wondering bc, while yes the BUnny is rather small, choosing a small ish area, DOES indeed scale out from original selection, but its rather limited, it doesn't scale to entire mesh.

I just want to understand how the math works there so I can better grasp why its doing this

TY so much I love your explantions they are very interesting 😉

[MagWeb · Accepted solution]

Do you mean the startup Falloff and its slider range?

Not sure about the startup Falloff value. To me it seems to be a certain number (9?) of triangle rings (as if you grew a selection 9 times). The startup Falloff distance doesn't depend on the size but on the mesh's density.

The sliders max value instead is 50mm. But bigger values are allowed. 

Two ways:

Either by numerical input (click on the parameter's number to edit)

or by dragging the slider over its limit while dragging a bit upwards simultaneously.

[Anonymous]

That explains a lot then, my mesh is quit dense in places to allow for design purposes, bunny , just used default density.

TY!!