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CADFEKO: Boolean operations with noentity at the output

I have a problem which is btw also present in HFSS. Boolean operarions with non-entity, or entities with Zero-dimension at the output throw an error.

Like when two intersecting parametric objects do not meet there should be nothing in the 3D space, only the operation in the hierarchy list.

And it is normal because that may be a solution to the optimization.

But instead, 3D engines refuse to work and make you suffer.

Is there a way to avoid it in FEKO? In HFSS I was making sophisticated if-then conditional moving of all the parts outside of the solution volume. But in FEKO it seems not applicable.

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Shannon_Mistry

Hi Andrew,

Can you share an example model to understand this better?

Regards,

Shannon Mistry

Andrew_21618

Hi Andrew,

Can you share an example model to understand this better?

Regards,

Shannon Mistry

No. As I said, it throws an error.

Just try to make two non-intersecting boxes. And apply boolean intersection to them.

My mind suggests that the intersection is an empty set. And that should be an object with no points in the object tree. But CADFEKO refuses to understand this simple thing.

Now apply boolean substraction. The same, an empty set is extracted from the first operand, and should produce the same object with no changes, not an error.

Another example is a box with zero thickness. It is simply a surface.

Why is it so hard to teach the engine these simple things?

Shannon_Mistry

No. As I said, it throws an error.

Just try to make two non-intersecting boxes. And apply boolean intersection to them.

My mind suggests that the intersection is an empty set. And that should be an object with no points in the object tree. But CADFEKO refuses to understand this simple thing.

Now apply boolean substraction. The same, an empty set is extracted from the first operand, and should produce the same object with no changes, not an error.

Another example is a box with zero thickness. It is simply a surface.

Why is it so hard to teach the engine these simple things?

Hi Andrew,

The intersection operation cannot be performed on two non-intersecting elements. It can only be used for overlapping entities. Please refer 2.8.4 Creating Complex Geometry Using Boolean
Operations from the Feko User Guide.

For the case of a box with zero thickness, you can use Construct-->Cuboid and create a cuboid. From the details tree, go to Regions-->Region1, right click--> go to its properties and change the medium to "free space". This will then create a hollow box with zero thickness.

Regards,

Shannon Mistry

Andrew_21618

Hi Andrew,

The intersection operation cannot be performed on two non-intersecting elements. It can only be used for overlapping entities. Please refer 2.8.4 Creating Complex Geometry Using Boolean
Operations from the Feko User Guide.

For the case of a box with zero thickness, you can use Construct-->Cuboid and create a cuboid. From the details tree, go to Regions-->Region1, right click--> go to its properties and change the medium to "free space". This will then create a hollow box with zero thickness.

Regards,

Shannon Mistry

thats what I am telling you. It is a underdevelopment, engine weakness and logical mistake.

Bolean operations are applicable to any sets. Intersection of nonintersecting sets is an empty set. there is no mistake in it.

I really hoped that there could be an override config option for this kind of "error" which is not an error.

And when implemented, it is a very powerful instrument of parametric analysis. When the engine thows an error and stops, it is an obstacle to creating efficient parametric models with arbitrary features.

Speaking about hollow box, I understand your point. There is a reason in your explanation. But still, it is logically weak. No matter how you look at it, a zero thickness box is a planar polygon, it should be treated automatically.