I'd say a hack is a technique with caveats that let's you work around a limitation. Ray tracing is still too computationally expensive so the current raster pip

I'd say a hack is a technique with caveats that let's you work around a limitation. Ray tracing is still too computationally expensive so the current raster pipeline is all a hack to work around that fact. It's also an incredibly well established and close to ground truth hack but there are lots of caveats where things go astray. Off the top of my head transparency is still largely problematic.