Overflow Processing of Edge Blend

In real situations, an overflow may quite often occur between the rounding surface and some elements of the solid geometry that are not the adjacent faces of the rounded edge. In such cases, the system may use special options for processing such overflows. These options are controlled in the Overflow Processing tab in the Parameters window.

This tab contains overflow processing options checkboxes and Inside Tight Corners processing drop-down

All checkboxes are enabled by default. In this case the system tries to apply all possible options in the order of their interface layout. So Process Smooth Overflow goes first, then Retain Cliff Edges along with its Process Cliff End sub-option, and finally Notch.

You can disable or enable necessary options by using checkboxes.

In case where all checkboxes are disabled an blend surfaces overflow other edges or faces, blend operation could not be created.

Process Smooth Overflow

This option is applicable when blend surface overflows an existing rounding of the processed body. Blend surface is deformed in the transition zone in order to provide tangency to the rounding surface.

 

 

Process Smooth Overflow option is applicable both to Roundings and Chamfers.

 

 

Retain Cliff Edges

Retains a sharp edge when the rounding surface "creeps" over it. Blend surface is formed by rolling a ball which is tangent to one of the initial faces and supported by a retained edge.

 

Retain Cliff Edges option is not applicable to chamfers.

 
Upon enabling Retain Cliff Edges option you can additionally enable/disable Process Cliff End sub-option, which processes the case, where only ending part of blend surface overflows a sharp edge.

 

 

Process Cliff End sub-option is not applicable to chamfers

 

Notch

Rounding is constructed in such a way that the element affected by the overflow is ignored. The rounding surface is not deformed in this case, and the surfaces of the notched element are trimmed or extended to the rounding.

 

 

Notch option is applicable both to Roundings and Chamfers.

 

 

In some case when Notch option is mandatory for creating a blend it might be applied automatically and independently of Overflow Processing checkboxes condition.

 

Inside Tight Corners

Some portions of model subjected to blending might be represented by surfaces with so small curvature radius that the blending ball of the specified radius cannot roll through while maintaining contact with sidewalls. In such a case, the system can use special processing for providing blending with the specified radius in the curved zone:

•Tight blends – in this case, the system will process curved zones using the fastest algorithm. The algorithm assumes that surfaces in these zones are created solely by blends of constant radius. If a type of an original surface is different and a blend cannot be created, an error is output.

•Tight faces – the system processes curved zones, assuming, that a zone of small curvature radius fully extends through some face of a sidewall.

•Tight partial – this is the most complex, but also versatile, algorithm. It allows processing cases, when a zone of small curvature radius covers a portion of a sidewall of a blend. In this case, a blend surface is additionally subdivided in order to provide correct processing.

 

Disabling unnecessary complex options allows to lower a time required for model regeneration.

 

Here are the examples of using different inside tight corners processing options: