The PGM trims offset loop geometry to maintain a consistent offset solution. However, the trimmed geometry may have had a constraint or dimension applied to it. In these cases the PGM will also modify the constraint scheme to reflect the new loop geometry.
The first example is an offset loop with a short edge in one corner. The opening part of the animation shows the effect of offsetting inwards without using the PGM's trimming and constraint reallocation technology. Next, the operation is repeated using trimming and constraint reallocation. The short edge is now trimmed out as the offset distance is increased. The PGM repositions the invisible trimmed edge, which still has the dimension applied to it, to pass through the appropriate vertex, as shown.
In the second case there is a circle tangent to an edge in the offset loop. As the offset distance is increased this edge is trimmed at the same time as the two adjacent edges. The PGM moves the invisible trimmed edge onto the untrimmed portion of the offset loop and the constraint continues to be solved.