topic Re: Oriented bounding box in Fusion API and Scripts Forum

Oriented bounding box

rolandas_vegis — Mon, 11 Nov 2024 11:44:36 GMT

Hello,

The BRepBody.orientedMinimumBoundingBox Property has been in Preview for 10months now.

When using this method of getting a orientedMinimumBoundingBox ir works wrong sometimes:

const auto physicalProperties = body->getPhysicalProperties(HighCalculationAccuracy); JCAD_ASSERT_FUSION_RESULT(physicalProperties); Ptr<Vector3D> xAxis; Ptr<Vector3D> yAxis; Ptr<Vector3D> zAxis; JCAD_ASSERT_FUSION_RESULT(physicalProperties->getPrincipalAxes(xAxis, yAxis, zAxis)); return Application::get()->measureManager()->getOrientedBoundingBox(body, xAxis, yAxis);

But the property on BrepBody works correctly.

Is it safe to release the BRepBody.orientedMinimumBoundingBox to users now?

Re: Oriented bounding box

BrianEkins — Wed, 13 Nov 2024 23:38:10 GMT

I'm sure this is an oversight, and the BRepBody.orientedMinimumBoundingBox property is OK to use.

Do you have an example model where the MeasureManager.getOrientedBoundingBox fails? I tried it with a random model, and it worked OK, so it must be a case-specific issue.

Re: Oriented bounding box

rolandas_vegis — Thu, 14 Nov 2024 06:42:22 GMT

Thanks, great that we can use it.

Yes, we issue is case specific.

Link to model: https://a360.co/3YK6yX3

Also an image showing for which component the box is wrong. MeasureManager.getOrientedBoundingBox returns sligthly rotated box, while BRepBody.orientedMinimumBoundingBox returns the correct box for this component.

Re: Oriented bounding box

BrianEkins — Thu, 14 Nov 2024 20:22:21 GMT

The MeasureManager.getOrientedBoundingBox and BRepBody.orientedMinimumBoundingBox differ in what they do and what you would use them for. The BRepBody orientedMinimumBoundingBox method doesn't require any input and calculates a tight-fitting bounding box for the body. The resulting box can be in any orientation to give the best fitting box.

The getOrientedBoundingBox of MeasureManager calculates a bounding box using the orientation you specify. It doesn't try to find the best fit. I get the same result as the minimum bounding box when I call this using the X and Y axes as the orientation. I don't know what directions you're using for the getOrientedBoundingBox.

Re: Oriented bounding box

rolandas_vegis — Fri, 15 Nov 2024 06:32:38 GMT

Thanks for explaining the difference, I was using it wrong then.