Hi, so there is a behavior in the latest versions of sketchup that move end point (vertex) automatically if they are close to one another…

It is causing inaccuracies in my model and I can’t find a way to stop the behavior.

for instance - If change the line segments in a circle from 24 to 48… which should result in even line segments that are all identical, Sketchup creates 48 line segments with varying lengths… because the end points collapse down to the closest end points of hidden geometry on the surface of the circle.

Sure I could redraw a circle every single time I need to do this - but it would be much better if this end point collapsing behavior could be switched off, so that It doesn’t add additional busy work to the model pipeline. and doesn’t break existing features of sketchup (such as the ability to edit the line segments amount of a curve - into different yet still equal segments.

The accuracy of my model is down to 6 decimal places, and yet this behavior still moves endpoints all over the place.

It is a really irritating behavior that needs to be toggleable if there isn’t an option to do this already?

I’m going to guess that you are working right down in the weeds, mm or very small inches. Sketchup doesn’t like tiny edges. It is easier to work at a larger scale.
It would be helpful to see one of your models that have these issues.

24 vertices → 48 vertices means new vertices at different locations. Some of them may and up near (as you say) endpoints of hidden geometry. “Hidden” doesn’t necessarily mean separated from anything you create in the same context. Only groups and components shield of their vertices, i.e endpoints of edges. If not grouped, new vertices may merge with hidden vertices.

As @Box mentioned, a shared model file would help nailing down the issue.

I can’t share a model because it is proprietary. - you would need to sign an NDA.

but it’s not an issue with the model - it’s a sketchup behavior - It does not matter if I am drawing a circle or just an intersecting line.

what is happening is… I draw a line to connect to intersect to another line — instead of the vertex staying where I want it to intersect… it jumps and merges with one closeby… meaning I can’t draw accurately.

I want to turn off the automatic vertex merging behavior… there seems to be a minimum distance that vertex’s can be apart before they merge… how do I edit or stop this behavior?

It may be that you are experiencing a less pronounced version of this - if you are working on file brought from a 2D based package - often these begin a long way from the world origin

Here is the same 48sided circle 100km from the origin - even here it’s starting to go weird.

This sounds like something I ran into long ago. I don’t remember if there was a workaround, but my gut says no.

If a new edge passes close to an existing edge’s end vertex, SketchUp does a calculation test to see whether the edges might have been intended to intersect there. Because computer arithmetic is involved in calculating the ideal path of the new edge, SketchUp must do this test to within a tolerance. If it concludes the new edge passes within range of the old vertex, SketchUp breaks the new edge into two parts, one leading from each end of the intended new edge to the old vertex. As I recall, the old vertex always takes precedence: SketchUp never stretches the old edge out to match the ideal path of the new one, it always breaks the new edge.

This can happen if length snapping is turned on and the old edge was drawn an exact length from an inexact starting point.

This is also a problem when you meant the edge to run to one vertex of a circle or arc and it snaps sideways to a different one in spite of the inference engine having shown a snap to the desired vertex of the circle.