Da Vinci Code objects

The Da Vinci Code Objects are objects that appear in some of Halo 3 's levels. These object are textured with a UV-unwrapped image (used to help artists paint textures onto 3D models). The image consists of a grid, with each tile containing a letter from a to p in alphebetical order, each line repeats the one above albeit shifted right by one letter. The name was likely inspired from the texture's slight visual similarity to the "cryptex" featured in Dan Brown's The Da Vinci Code.

Easter Eggs
pJ1stsjBs8w FlH2da82JMM On Sandtrap and Sandbox, spherical objects have been found. These objects, dubbed "easter eggs" and also known as "Da Vinci Eggs", are located near or inside large, tower-like Forerunner structures, and in both levels serve to keep the player from exiting the level.

Sandtrap
In Sandtrap, the Eggs fire orange beams into the sand whenever a player tries to exit the map; these beams activate Brute Landmines that are buried along the level's perimeter. The beams themselves are harmless, unlike the beams on Sandbox. In both cases, the Eggs' kills are attributed to The Guardians.

To get a closer look at the Eggs in Sandtrap, you'll need to use Pan Cam to exit the map in Theater and fly to any of the towers. The eggs will be near the top-right of the towers.

Sandbox
In Sandbox, the Eggs fire subtler but more powerful beams directly at escaping players, killing such players almost instantly. The beams on Sandbox are also much more accurate, as they were meant to target specific players. However, unlike the beams on Sandtrap, Sandbox's beams can be blocked by Bubble Shields and most Forge Objects. These beams are very similar to the projectiles fired by a Gauss Warthog.

To see the eggs, two players must cooperate. One player (Person A) must, while in Edit Mode, exit the map from the Sky Bubble by spawning a Teleporter outside of the map. Person A must then fly to a tower (but watch out for kill barriers) and spawn a turret against the light in the tower. A second player (Person B) must then man the turret and have Person A pick the turret up. Person A should drag Person B up the wall while B is still against it. Towards the middle of the light, the Easter Egg can be seen.

Da Vinci Cube
byt-R7iMyEo On Heretic, an untextured cube is hidden inside each of the lifts at the center of the map. To reach one of these "Da Vinci Cubes", a player must place a Machine Gun Turret against the top of the lift. They should then proceed to use the Forge Turret Glitch to enter the small compartment that holds the cube.

The Da Vinci Cubes power their respective lifts; overloading the map will cause the cubes to vanish, disabling the accompanying lifts. There are only three known Da Vinci Cubes on Heretic, and their purpose is unknown -- lifts on other maps, like Sandtrap and Valhalla, do not appear to require such cubes. It is possible, however, that Da Vinci Cubes exist on those maps and simply haven't been found. Interestingly, the Cubes are noticeably smaller than the Easter Eggs on Sandtrap and Sandbox.

Da Vinci Towers
ld2agaDDe2g In the Halo 3 Campaign level The Covenant, the Time Travel Glitch can be used to reveal three Da Vinci Towers hidden outside of the level boundaries. The towers do not appear in normal gameplay, but seem to be glitched or altered copies of the shield-generating towers that the level's objectives center around. Most of the towers' surfaces are untextured, and the non-solid towers don't appear to serve any purpose.

Although it is possible to see a half texture half Da Vinci letters on the outside of the tower.

First get to the part of the level where your enroute to the third tower by hornet. Then destroy the other two hornets. Then fly to the ledge between the AA wraith and abandon the Hornet there because you need a banshee to perform it.Wait for a chance to hijack one, this may take a few trys due to after a few come to within that distance they ignore you and they tend to boost near the player. After that go the horseshoe shaped arch between the second and third towers and go to the top of the cliff of the mainland,go almost directly away from the water and keep boosting until you hit an invisible wall.then go up a little, after that you must face up a little the entire time then back to the coast then pass the second tower to the first. After hitting an invisible wall you can look down and see canyon between where the level started to the first tower. Go into the missing area of it then go up the canyon and above the lake go up as much as possible then go to the highest accessable area of the first tower.

There you will find the other side of the Da Vinci tower partially under a regular texture.

It is possible that Bungie created two versions or layers of the normal shield-generating towers. The outer layer is immutable, but the inner layer (the "da Vinci" layer) will vanish if the shield generators in the towers are disabled. It is entirely possible that the Da Vinci Towers are projecting the beams that power the shields, which would explain why disabling the shields removes the towers.

Trivia

 * In Halo 3: ODST, in Kizingo Boulevard (Level), there is a large rectangle SW of mombasa island outside and on the floor of the level map . This rectangle is a "Da Vinci" rectangle that has no strategic placement and located is surrounded by a void. A void contains no textures and no solids and is empty hence it is called a void.
 * More untextured DaVinci Code Objects can be seen in the Halo 3 ViDoc Et Tu Brute?.