Wednesday 5 February 2014

View Range and Phase Filters

A recent problem arose where phase filters are used to show demolished columns. In 3D and section views, everything appeared fine, but in plan, these columns weren't changing appearance as per the phase filter override. The suspected cause was in the view range for the plan and after a bit of head scratching, it was determined that the columns whose tops terminated within the 'View Depth' band of the view range would ignore the phase filter overrides. This has been recreated in the images below:

Projection - No Phase Filter

Projection - Phase Filter Applied

Cut - No Phase Filter

Cut - Phase Filter Applied

View Depth - No Phase Filter

View Depth- Phase Filter Applied

I'm not going to go into a full explanation of how view ranges work, but there are a couple of very good ones by others here and here that helped me get to the bottom of this.