Question regarding chain selection and preselection in macro

Hi, I have two questions about selection in Rhino:

  1. The selchain command seems to require manually picking each item from the dropdown, rather than automatically selecting the chain of items (edges/ curves/ surfaces) by picking only one item. Is this the intended way to use the command or am I missing something? For example, I would like to use selchain, pick one edge of an open box and then have all the other edges around the opening selected. Similar to how Fusion 360 handles chaining. However, when I set the continuity to position and angle threshold to 90 it does not change the command’s behavior anything.
  2. Is it possible to create a macro for [’-selblockinstancenamed], where you can use preselection? I basically want to select an block, hit the macro with a shortcut and have the instances selected, rather than hit the command and select the block afterwards.

Actually, come to think of it, preselection can be set by using a combo of “select none” and “select previous” like so (and I then mapped this to my shortcut):

'selnone -SelblockinstanceNamed s _selprev _enter

Hello - if there are multiple candidates to chain, it needs to know which one you care about… the curve or the edge for example, if both are say tangent to the previous curve. In V7, you can force edge selection by unchecking Curves in the selection filter - that does not work in V6.


That sounds promising about V7. Still, what am I missing here, it shouldn’t be that hard to chain open edges on an extrusion, should it?

Hello - if you chain for position, there is always going to be a question when more than one edge is encountered - hard to see how to avoid that…


In that case, I would like to request an option in chain select to chain naked edges, that would do the trick for me here.

I will add the wish to the pile - but, what are you doing here? Do you need the curves as input to some other surfacing operation? I’m sure you know, but DupBorder will get those as curves in this case, not sure if that helps here.

RH-61126 SelChain: filter for naked edges



Thanks Pascal!
My intent was indeed to use dupedge, dupborder is something I hadn’t seen yet, so thanks again.

But yeah, for architectural models chain selecting edges for a series of walls with open polysurfaces is a big help for transforming as well. FYI this was something I ran into when I received a sloppy sketchup model from a colleague with all forms joined non-closed surfaces.

RH-61126 is fixed in the latest Service Release Candidate

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@brian, That’s what I call a quick fix! Thanks to the team for the work!

You’re welcome!