qAdjacent edges count different to UI

graham_lock · March 30

Hi,

I have a situation where qAdjacent doesn't seem to detect edges in the same way as the UI.

For example the following shows a part with 4 edges in the UI:

The sketch looks like this:

When I run:

var qAdj = qAdjacent(face, AdjacencyType.EDGE, EntityType.EDGE);

it returns only 3 edges - the curved edge and RHS vertical are considered as one edge:

debug(context, qNthElement(qAdj, 2), DebugColor.GREEN);

What do I need to do in order for all faces to be detected?

Thank you.

NeilCooke · April 3

Sweep and loft will sometimes merge tangent faces into one with no user control over it.

lana · April 4

There is some control over topology exposed to Feature script. Notice loftTopology argument of opLoft. You can make it merge less.

Jed_Yeiser · March 31

Can you share your code? This will make debugging easier. I'm guessing you've tried this already, but have you tried:

addDebugEntities(context, qUnion([qAdjacent(face, AdjacencyType.EDGE, EntityType.EDGE)]), DebugColor.GREEN);

I suspect that qAdjacent is actually finding the correct edges, but you're debug statement does not include all found edges. My apologies if that's not the case - hard to tell without a code snippet.

If your issue is that you're finding all edges, but two edges are considered one element… that's a different kettle of fish and likely relates to some tangency continuations. I tend to turn queries like this into arrays for readability (even though it's not strictly necessary). What happens if you do the following?

var foundEdges = evaluateQuery(qAdjacent(face, AdjacencyType.EDGE, EntityType.EDGE));
println('Found ' ~ size(foundEdges) ~ ' edges!');
for(var foundEdge in foundEdges):
  addDebugEntities(context, foundEdge,DebugColor.GREEN);

graham_lock · March 31

Thank you for your reply.

Running your code produces:

Found 3 edges!

All 3 edges are highlighted in green.

The problem exists in my project which I cannot share but I haven't managed to reproduce the issue in a test document.

You mentioned tangency continuations?

NeilCooke · March 31

If you can't reproduce it elsewhere, can it be remodelled here to fix it? Does sound like a bug - please create a support ticket.

graham_lock · March 31

I've found that if I select the face of the part then only 3 edges are detected, if I select the sketch from which the part is generated then 4 edges are detected.

My input annotations is:

annotation { "Name" : "Front Faces of all Formers", "Filter" : EntityType.FACE }
definition.formerFaces is Query;

Does this help?

jelte_steur814 · April 1

I noticed there doesn't seem to be a line on the side face of the 'former'.

not sure how you had set your tangent lines to be displayed though, so I didn't think anything of it.

Can you turn tangent lines on and show/check that area in more detail?

If the side face there isn't split, it makes sense the edge isn't either.
It would still be weird that the side face isn't split though.
but then at least you'll know the issue is not in the query, but in the results of the extrude…

graham_lock · April 1

Thank you for your reply.

I've literally just made progress and fixed the problem but I'm not sure why the problem actually occurred.

The formers are internal components of a skin.

The skin is formed by surface lofting between the sketches which define the skin profile.

So I start with:

I then loft to form the skin, this is where the problem lies. If I loft all sketches at once I don't get any side splits:

If I make 3 separate lofts I get the side splits:

I then boolean them together to get a single skin:

Then the former parts are created at appropriate points by creating curves within the skin, filling and thickening:

I'd like to understand why the lofting workflow has this affect.

jelte_steur814 · April 3

I'm guessing a bit here but what i can see happen is

When you loft from one sketch to a second sketch, the solution is linear. so from one line to a second line, it will create a planar face which it will recognise and create separate from the curved top face.
when you loft between 3 or more sketches, the loft creates a curved face between the straight lines to create a smooth result. this is no longer a separatable planar face and is therefore integrated with the curved top face…

graham_lock · April 3

Thank you, yes that makes a lot of sense.

NeilCooke · April 3

Sweep and loft will sometimes merge tangent faces into one with no user control over it.

graham_lock · April 3

Thank you @jelte_steur814 and @NeilCooke I know what to avoid now.

lana · April 4

There is some control over topology exposed to Feature script. Notice loftTopology argument of opLoft. You can make it merge less.

graham_lock · April 4

Thank you I’ll look into that.

qAdjacent edges count different to UI

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