Undoing operations

graham_lock

Hi,

I have flat parts where I extrude / offset edges for splitting.

The image below shows a typical part which started as a solid, where the holes have been cut by extruding the outer edges, offsetting them, splitting the original part with the offset edges and then deleting the inner bodies created by the split to form the holes and then adding fillets.

Depending on how the parts are constructed, the required directions of the extrudes and offsets vary, currently I have two Boolean UI parameters for selecting the correct combination which is a bit clunky.

Ideally I'd like to be able to step through the four direction combinations in code until I hit the one which is correct.

My question is, is it possible to undo an operation(s) so I can retry or would I need to create duplicate parts on which to test the directions? Or is there another way?

Thank you.

NeilCooke

Yes, you can use startFeature and abortFeature/endFeature. You can see a really good example in the Fill pattern feature which check that a pattern does not self-intersect before applying the pattern.

https://cad.onshape.com/documents/57361ad4e4b00e5012c3857c/w/afc99caf9d2bcd4451843939/e/2262facc4328a254dd7deb6a

Caden_Armstrong

@graham_lock You could check a qcreatedby("splitPart") → isQueryEmpty
If the split happens, the query shouldn't be empty.

NeilCooke

All arrow notation does is replace the first parameter in the following function. So it won’t work in this case.

Caden_Armstrong

my bad, I was typing on a phone and assumed you wouldn't literally copy paste the code. I left syntax as homework for the reader.

isQueryEmpty(context, qCreatedBy(featureId + state + "splitPart1"));

NeilCooke

Yes, you can use startFeature and abortFeature/endFeature. You can see a really good example in the Fill pattern feature which check that a pattern does not self-intersect before applying the pattern.

https://cad.onshape.com/documents/57361ad4e4b00e5012c3857c/w/afc99caf9d2bcd4451843939/e/2262facc4328a254dd7deb6a

graham_lock

Thank you, this should be exactly what I was looking for.

I'm running into problems with scoping and not sure how to resolve them.

Also when trying to determine whether the split has worked I'm comparing body counts before / after the split which is pretty ugly! I tried qSplitBy but couldn't get it to give a unique result upon successful completion of the split?

I've put together a test document showing the problem:

https://cad.onshape.com/documents/38e858c78f7e1cb2331da497/w/6915ba29ec08cfa14b2598ba/e/7f7051573aa0404f8773666e

Any further help appreciated.

graham_lock

I've resolved the scoping issue - I had a missing abortFeature;

graham_lock

So my only remaining question is, is there a better way to know the opSplitPart has worked?

I currently have the following:

var countBodiesBeforeSplit = size(evaluateQuery(context, qEverything(EntityType.BODY)));

                opSplitPart(context, featureId + state + "splitPart1", {
                            "targets" : tmpPart,
                            "tool" : qCreatedBy(featureId + state + "extrude1", EntityType.BODY),
                            "keepTools" : true
                        });

                // tried qSplitBy but didn't work

                // must be a better way
                var countBodiesAfterSplit = size(evaluateQuery(context, qEverything(EntityType.BODY)));

                if (countBodiesAfterSplit > countBodiesBeforeSplit)
                {
                    // correct combination found

I'm counting the number of bodies before and after the split - I'm sure there must be a more efficient way?

Thank you.

Caden_Armstrong

@graham_lock You could check a qcreatedby("splitPart") → isQueryEmpty
If the split happens, the query shouldn't be empty.

graham_lock

Thank you that works fine.

graham_lock

When I tested this I didn't use arrow notation as I've never tried it before.

I'm using:

qCreatedBy(featureId + state + "splitPart1") -> isQueryEmpty()

How do I get context to be the first parameter of isQueryEmpty?

Thank you.

NeilCooke

All arrow notation does is replace the first parameter in the following function. So it won’t work in this case.

Caden_Armstrong

my bad, I was typing on a phone and assumed you wouldn't literally copy paste the code. I left syntax as homework for the reader.

isQueryEmpty(context, qCreatedBy(featureId + state + "splitPart1"));

graham_lock

Thanks, I didn’t actually copy the code, I tested it using non arrow syntax, but since I hadn’t tried arrow syntax before I though I’d give it a go.