Part Draft

fastwayjim · April 2016

So, my first stab at FS is going to be a "Part Draft" feature. I just want to query for a neutral plane, and a body - and I want the feature to split the body with the plane, then draft both sides.

I figured I'd start with the draft, then incorporate the split. I could get the draft working when I queried for the faces, but I'm having trouble getting FS to automatically find the faces. Here's the code

If I just query for draftFaces, I can get the draft to work, so I think there's something wrong with my intersect/filter?

Thanks for the help!

fastwayjim · April 2016

BTW, this is what it looks like today, using standard features:

Image: https://us.v-cdn.net/5022071/uploads/editor/rc/7phxffsrcxla.png

In order to get the pull direction correct on both sides, the body needs to be split, and the second draft needs the direction flipped, then a union to put it back together. I'm going to do it all in one feature!

ilya_baran · April 2016

With the code above, you should be getting an error on the qIntersectsPlane line -- the second argument is expected to be a Plane, while definition.neutralPlane is a Query. To get a Plane from a Query for a planar face, you can use evPlane:


var intersect = qIntersectsPlane(definition.draftBody, evPlane(context, { "face" : definition.neutralPlane }));

See this paragraph in the docs for a slightly longer explanation.

ilya_baran · April 2016

One more issue I just noticed

qIntersectsPlane filters out entities from whatever is passed in as the first argument. The query I wrote asks "which of the bodies returned by draftBody intersect the neutral plane?" whereas what you want is "which of the faces owned by draftBody intersect the neutral plane". To do that, use
qOwnedByBody(definition.draftBody, EntityType.FACE) instead of definition.draftBody.

fastwayjim · April 2016

Thanks, let me digest this a bit., For the record, the original code had zero errors.

ilya_baran · April 2016

I believe the error in the original code would not have been detected in the Feature Studio, but rather as soon as you tried to use your feature in a Part Studio. It would have been reported as a warning.

fastwayjim · April 2016

HAHA YES!!! I got it!!!!! (No I didn't spend all day on it, I promise)

Here's the code, I just used the qSplitBy to get the faces for the draft, and then I used a qUnion to get them both for the boolean. Is this a good/clean/smart way to do it?

Image: https://us.v-cdn.net/5022071/uploads/editor/co/lo8nvh9ci0jc.png

ilya_baran · April 2016

Yes -- that looks good -- basically, how I'd do it. You could probably pass in definition.draftBody for the "tools" parameter (instead of the qUnion of qSplitBy's) and it'll do the right thing.

fastwayjim · April 2016

Got it. I didn't even try that, because I guess I assumed that draftBody wouldn't work because new bodies were created after the split feature, and therefore the draftBody was then outdated... Is that not how it works?

fastwayjim · April 2016

Also, quick question: I copied "targets" : qUnion([]), from the "real" draft feature. Is this the preferred approach for an empty value? Could I just omit that line of code to keep things neat and tidy?

ilya_baran · April 2016

When entities split and merge, we try to preserve their identities. So a qCreatedBy query that resolves to a body before a split should resolve to the bodies that resulted from splitting the original body. If the query had been evaluated (converted to "transient" queries) then they would be outdated.

You can omit the "targets" : qUnion([]) line -- it's not required in this case as per the opBoolean documentation.

One more suggestion: for putting code into the forum, you can use the "code" option in the paragraph menu instead of pasting an image -- that way people can copy/paste your code e.g. to try it out or to reuse pieces.

fastwayjim · April 2016

Awesome, thanks! Here's the final code, with separate angles for top/bottom and the "reapply fillets" option available:

annotation { "Feature Type Name" : "Part Draft" }
export const partdraft = defineFeature(function(context is Context, id is Id, definition is map)
    precondition
    {
        annotation { "Name" : "Neutral Plane", "Filter" : EntityType.FACE, "MaxNumberOfPicks" : 1 }
        definition.neutralPlane is Query;

        annotation { "Name" : "Top Draft Angle" }
        isAngle(definition.draftAngleTop, ANGLE_360_BOUNDS);

        annotation { "Name" : "Bottom Draft Angle" }
        isAngle(definition.draftAngleBot, ANGLE_360_BOUNDS);

        annotation { "Name" : "Part to Draft", "Filter" : EntityType.BODY && BodyType.SOLID }
        definition.draftBody is Query;

        annotation { "Name" : "Reapply Fillet" }
        definition.reFillet is boolean;
    }
    {
        //Split the part through the neutral plane
        splitPart(context, id + "splitPart1", {
                    "targets" : definition.draftBody,
                    "tool" : definition.neutralPlane
                });
        //Select the faces on the front side of the split to draft
        var draftFacesFr;
        draftFacesFr = qSplitBy(id + "splitPart1", EntityType.FACE, false);

        //Draft the front body
        draft(context, id + "draft1", {
                    "neutralPlane" : definition.neutralPlane,
                    "draftFaces" : draftFacesFr,
                    "angle" : definition.draftAngleTop,
                    "pullDirection" : false,
                    "reFillet" : definition.reFillet
                });
        //Select the faces on the back side of the split to draft
        var draftFacesBa;
        draftFacesBa = qSplitBy(id + "splitPart1", EntityType.FACE, true);

        //Draft the back body
        draft(context, id + "draft2", {
                    "neutralPlane" : definition.neutralPlane,
                    "draftFaces" : draftFacesBa,
                    "angle" : definition.draftAngleBot,
                    "pullDirection" : true,
                    "reFillet" : definition.reFillet
                });
        //Union the bodies back together
        booleanBodies(context, id + "boolean1", {
                    "tools" : definition.draftBody,
                    "operationType" : BooleanOperationType.UNION
                });
    }, { /* default parameters */ });

Enjoy!

fastwayjim · April 2016

This is the resulting geometry. Each part was drafted with a single feature!

Image: https://us.v-cdn.net/5022071/uploads/editor/o2/2926ivsyz25z.png

traveler_hauptman · April 2016

nice!

Part Draft

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