Wish for "RefitTrim" + a bug maybe?

Wish: Make it possible for the ! _RefitTrim command to optionally work even on surface edges that are divided into several pieces, without the need to use ! _MergeEdge (with the “All” option) prior that. :slight_smile: A command line option for that that could be remembered within the current session would be welcomed.

Bug: I have two very simple planes split by a basic line. Then I build a blend surface in-between that also has totally straight sides (U direction: degree = 1, CV count = 2; V direction: degree = 5, CV count = 6). However, when I use the ! _RefitTrim command, it shrinks the flat surfaces more than the target size suggests and the bottom corner of one of those surfaces leaves nearly 0,37 mm gap. The absolute tolerance of my scene is 0,001 mm and angle tolerance is 0,1 degree.
I also noticed this behaviour of overly-shrinking while working on some other models in the past weeks, but since this happens so often even on very basic planes with walls split by a basic straight line, I think that it needs to be addressed. It should try to keep the same size as the trimmed surface before running this command. Shrinking it way too much basically leaves gap and forces me to use “Match surface” every time I use “RefitTrim”.

Yep, I think this is it:
RH-61280 RefitTrim: Fix the end points

RH-64006 Refittrim: Merge split edges




Thanks, Pascal! Really like the way you and the “McNeel” team try to help with improving Rhino for everyone! :slight_smile:

Hi @pascal, it’s been a year since you added reports to those two bugs to the pile. Recently I used the RefitTrim tool quite often and unfortunately it still produces some unwanted deviation at the end points that make it far less usable. In those situations where RefitTrim fails I’m forced to use MoveUVN and/or Scale1D to individual control points, which takes more time and is less accurate. Could we expect some fix of this particular bug in any reasonable time? :slight_smile: Possibly for Rhino 7.

Here is another example where the end points were moved far from the expected position rather than staying at the exact same position as the split edge:

@Rhino_Bulgaria There should be a whole slew of fixes and improvements to all the RefitTrim stuff in the very next WIP, so please keep your eye out for those


Thanks for the reminder, I will download the latest Rhino 8 WIP tonight and try some models that previously had issues with the tool.