Partial invisibility



A partial invisibility powerup (called blur sphere in the manuals) is an item that appears as a floating red and blue orb with a pulsing eye-like pattern.

Picking up this powerup will grant the player partial invisibility for 60 seconds. The player's sprite (in multiplayer mode) will appear similar to that of the spectre, while the affected player will see their own weapons and hands as partially invisible. When five seconds remain, the weapon will begin blinking, signaling the end of the artifact's effects; the player sprite however remains fully blurred until all 60 seconds elapse. Picking up another partial invisibility item while a previously collected one is still active resets the duration to 60 seconds; any surplus time is lost. For this reason it is best to not collect another sphere until the current one is about to expire.

Monsters firing upon an affected player will have their accuracy reduced, in that their aim is offset by a random angle, causing them to miss more often. This however may cause more experienced players to inadvertently dodge toward incoming projectiles, being accustomed to monsters firing directly forward. Nevertheless, a blur sphere confers a definite advantage against long-range hitscan attacks such as those of zombies or spiderdemons. The partial invisibility is unable to disrupt monster melee attacks, homing missiles, or the arch-vile's flame attack.

Partial invisibility can also be invoked with the cheat code idbeholdi.

In -altdeath mode, partial invisibility and invulnerability spheres do not respawn. Some source ports allow flags to be set to cause them to respawn.

This item is included in the items percentage displayed at the end of each level.

Data
In classic Doom, partial invisibilities are first encountered on these levels:

The IWADs contain the following numbers of partial invisibilities:

Other games and ports


Due to difficulty in rendering the effect, all partial invisibility spheres were removed from the Atari Jaguar map set, and all other ports using its map set do not contain any of this powerup in those maps. Most were replaced with soul spheres.

The Sony PlayStation version restored the powerup to its vanilla appearance but, as with spectres, applies translucency to the player's sprite and weapons. The powerup only occurs in original maps made for the port and in Doom II levels – it was not added back to maps adapted from the Jaguar version.

Doom 64's partial invisibility item has the appearance of a dark red sphere with a central core emitting multiple electric arcs. Like the PlayStation version, the marine will appear slightly translucent.

There is an invisibility powerup in Doom 3, appearing chiefly in multiplayer. It has no effect on monsters, only rendering the player translucent.