As I understand the article right, at: http://www.modwiki.net/wiki/Visportal It says that a world brush will not block the field of view of the player (see right figure on the linked page). Would this mean, that the attached figure is true? (It was created as a illustration of my understanding) And if the Field of view goes through the world brushes, how come a room could be sealed by putting a visportal face into the doorways (if the FOV would still go through the world brushes). It's hard to describe, but I think my understanding of visportals is wrong. ATTACHED FIGURE 1 in comparison to A.F. 2