Simplify 3D used to have a "random infill" pattern and it was removed. People complained about it because it made weak parts. But there is actually an application for it, which I used.
The random infill pattern allowed me to make optically opaque or transparent (to various degrees) and uniform parts when viewed from the Z direction. With less than 100% infill, now, light shines through as the infill pattern lets it through the voids. However, with random infill I was able to print various percentages of infill, and when held up to the light, the parts varied in transparency but still looked uniform. This allowed me to do cool things with light.
I'd like to see the return of that feature.