SScissorRectBox

A ScissorRectBox is a widget that clips all its children using a scissor rect that matches it clipping rect in LAYOUT SPACE (the way it is provided in OnPaint). This ensures that any child widgets with render transforms do not "bleed out" of this parent container.

there is a significant performance impact to using one of these widgets because any widgets inside this one end up in a separate set of batches using that scissor rect. Keep in mind that this widget will use the LAYOUT clipping rect to clip children, since hardware clipping rects do not support non-aligned rectangles. If a render transform is applied to this widget itself, the results will not be as expected.

This class is provided as a STOPGAP for design-time widgets (like the UMG designer itself) until a more robust clipping solution can be put in place.