Boolean Union Failure: Is there way to detect where? Solved in V6

I’ve not a problem at the moment, but next model that I’d like to depend on boolean to speedup a bit.
I’ve seen overlapping of surfaces, position of creases, tolerance problem seems to cause
errors in booleans.

I was wondering if there is a way to detect where the failure occurs when it occurs, so
it’ll be easy to find where to change.
Hoping Rhino will somehow at the point of failure remember the curves or surfaces where it failed and when error is shown if the place is just highlighed… that’ll be great.

The first step in any Boolean operation is to intersect the surfaces and find the curves common to both. These curves are used to Split the surfaces. Based on the surface normal direction . of the surfaces and the specific Boolean you chose, Rhino then deletes and joins the appropriate surfaces.

The most common problem is incomplete intersection curves caused by poorly fitting surfaces. Troubleshooting a failed Boolean almost always starts with intersecting the surfaces and carefully inspecting the resulting curves, looking for gaps and overlaps.

The FAQ about failing Booleans goes over this and the other possibilities.

I guess it just needs to be tackled one at a time…

For the FAQ, this is the one? Looks quite comprehensive.

Yes, that’s the one.
If you understand how to do a Boolean manually but Intersecting the surfaces, Split/Trim using those curves, and joining the results into what you need, then you will have all the tools you need to troubleshoot failures.

I think I should be able to do manually. If I get stuck I’ll come back to this forum.

I guess if there’s multiple item that are booleaned at once when the error occurs to have a notice which object failed it might help in identifying there error point.

@Toshiaki_Takano, In Rhino 6, errors in boolean operations will put dots at the locations where problems arise. When you select the dot(s) and go to the properties page, there is a short description of the problem.

For the announcement of this feature and a sample file, check this post:

Very nice! Just the upgrade needed.
Anything to point to the error really saves time.
Show edges ->Naked edge is also great in that sense.
I’ll put this as solved. Thanks!