Hi Mike, yup transparency in the display has been on the wishlist for quite some time.

It's not particularly easy to add - the way video cards work it's not possible to just set a single attribute and get proper object transparency, the polygons that you want to make transparent need to be sorted from back to front and sent to the video card to be drawn in that back to front order. So it's something that could easily have poor performance unless it is done quite carefully.

- Michael