Failed Subtraction

[MWA]

Has anyone else encountered this strange phenomenon?

In a particular project, I was dealing with a group of several complicated 3d solids....many additions, subtractions, fillets, splits were used to achieve each the final shapes.

Sometimes, while working in the file, and I would perform a non solids task like zoom in or flyover, and the shapes I made, had turned into an object called a failed subtraction; a textureless box roughly the overall dimensions of the original objects.

I was using v11 at the time, and have had it happen to me in 12.5

Anyone bump into something like this in 2008?

Avoidable with 2009?

Anyone from NNA?

Thanks!

[mike m oz]

The sort of issues you are referring to are very much avoidable in VW 2009 because of the robustness of the modeling with Parasolids as the kernel.

[PVA - Admin]

After you get complex objects modified by complex objects further altered by MORE complex objects, this tends to happen.

The best fix pre-2009 is to taxe the two objects you wish to operate on, and convert them to a generic solid BEFORE doing the subtract/add/fillet. You dont need to do both of the objects all the time, and sometimes just the components of complex objects or their subcomponents need be changed to generic solids in order to alleviate this.

(Modify > Convert > Convert to Generic Solids)