How do I orient an ellipse (skEllipse)?

Aaron_Hoover

I'm generating an ellipse on a plane with skEllipse and I'd like to be able to rotate it in plane with respect to the coordinate system of the sketch plane. One way to do this would be specify the angle of the major axis wrt the X axis of the coordinate system, but there's no angle parameter in the skEllipse definition. So, I figured when I specify the "majorRadius" field perhaps I could pass a 2D vector rotated by the angle I want (with the minorRadius rotated by the same angle.) But, I get the following error:

Precondition of skEllipse failed (value.minorRadius is undefined || is...)
		232:5	onshape/std/units.fs (val is ValueWithUnits)
		69:5	onshape/std/valueBounds.fs (isLength(value))
		439:5	onshape/std/sketch.fs (skEllipse)

lana

Please try this:

annotation { "Feature Type Name" : "Ellipse" }
export const fEllipse = defineFeature(function(context is Context, id is Id, definition is map)
    precondition
    {
        annotation { "Name" : "Angle" }
        isAngle(definition.angle, ANGLE_360_BOUNDS);
        
        annotation { "Name" : "Major Radius" }
        isLength(definition.majorRadius, LENGTH_BOUNDS);
        
        
        annotation { "Name" : "Minor Radius" }
        isLength(definition.minorRadius, LENGTH_BOUNDS);
        
    }
    {
        const sketch = newSketch(context, id, {
                "sketchPlane" : qCreatedBy(makeId("Top"), EntityType.FACE)
        });
        
        const center = vector(0, 0) * meter;
        const majorAxis = vector(cos(definition.angle), sin(definition.angle)) * meter;
        
        skEllipse(sketch, "ellipse1", {
                "center" : center,
                "majorAxis" : majorAxis,
                "majorRadius" : definition.majorRadius,
                "minorRadius" : definition.minorRadius
        });
        
        skSolve(sketch);
    });

majorAxis is not well documented and is2dPoint precondition is wrong, actually a normalized 2d vector is expected.

kevin_o_toole_1

+1 to everything above, though note that the majorAxis does work with lengths that aren't 1 meter (e.g. vector(1, 1) * inch is fine). I'll add documentation for this argument in the standard library for a future release!

lana

Please try this:

annotation { "Feature Type Name" : "Ellipse" }
export const fEllipse = defineFeature(function(context is Context, id is Id, definition is map)
    precondition
    {
        annotation { "Name" : "Angle" }
        isAngle(definition.angle, ANGLE_360_BOUNDS);
        
        annotation { "Name" : "Major Radius" }
        isLength(definition.majorRadius, LENGTH_BOUNDS);
        
        
        annotation { "Name" : "Minor Radius" }
        isLength(definition.minorRadius, LENGTH_BOUNDS);
        
    }
    {
        const sketch = newSketch(context, id, {
                "sketchPlane" : qCreatedBy(makeId("Top"), EntityType.FACE)
        });
        
        const center = vector(0, 0) * meter;
        const majorAxis = vector(cos(definition.angle), sin(definition.angle)) * meter;
        
        skEllipse(sketch, "ellipse1", {
                "center" : center,
                "majorAxis" : majorAxis,
                "majorRadius" : definition.majorRadius,
                "minorRadius" : definition.minorRadius
        });
        
        skSolve(sketch);
    });

majorAxis is not well documented and is2dPoint precondition is wrong, actually a normalized 2d vector is expected.

Aaron_Hoover

Thanks! That did the trick. 

kevin_o_toole_1

+1 to everything above, though note that the majorAxis does work with lengths that aren't 1 meter (e.g. vector(1, 1) * inch is fine). I'll add documentation for this argument in the standard library for a future release!