Sprites are used for certain structures or for decoration. Every character in Baldi's Basics Plus uses sprites for their design and are never a 3D model in-game.
All sprites are front-facing 2D sprites, meaning 2D sprites that constantly face the camera. The only non front-facing 2D sprites are 1st Prize, The Test, Baldi's Bus and the "NO" signs seen in Baldi's Basics Plus Early Access.
In the original Schoolhouse, there are papers, sheets with pencils, and notebooks (not to be confused with the objective notebooks) found laying on desks inside the Classrooms. The Player can see a stickman on the paper but it can't be for sure. The notebooks on the table cannot be picked up, unlike the other notebooks that the Player needs to collect. The rest of them are simply real photos with backgrounds cropped out.
A full view of this large globe (via hacking).
Inside the Principal's Office and a few Faculty Rooms, there are earth globes. The size of the globes vary, some are a normal size but in one Faculty Room, there is an unusually giant one seeming to clip through the floor, as seen in the original Schoolhouse. The globes are also used in the Super Schoolhouse, but only in the Full Game Early Demo
Papers
Pencils and Post-it Notes
Notebooks
Globe
Room Decorations
Schoolhouse
Tree-like plants in brown pots are seen in some Hallways, Faculty Rooms and Exits.
The "EXIT" signs are used for Schoolhouse's exits. There is also another "EXIT" sign in a Faculty Room with a Swinging Door Lock, right above a massive globe.
The balloons are used for the party event at the Principal's Office, appearing in multiple sorts of colors: Orange, green, blue, and purple.
In Baldi's Basics Birthday Bash, these balloons can be seen almost everywhere in the Schoolhouse. The balloons can be pushed and even slow the Player's movement when trying to pass them. Updated in the Full Game Early Demo, the collision is removed and makes the Player able to pass through the balloons more easily. Furthermore, a single red balloon is hidden, and can be found at the Outdoor Areas from the Schoolhouse's west wing when using hacks. If observed carefully, the number 99 written backwards is located on the left side.
In the Cafeteria, there are multiple identical restaurant-based lunch meals on every table. The tray seems to have a drink, some load of fries, and some bread or a burger inside of what looks like some tin foil.
In Baldi's Office, the Player can find a modeled banana above Baldi's desk. Not much is known about this banana or why it is in Baldi's Office. There is also a banana on one of the tables in the Playground area only in the Full Game Early Demo.
Super Schoolhouse
There are also completely 3D-modeled trees in the Playground area, being the only plant life so far to be a 3D model, however it appears as a 2D billboarded sprite.
There are photo-realistic trees littered around the whole forest in the camping field trip, having grayish wood and light green leaves. On rare occasions, a tree with the number 99 on the trunk will spawn. There are also "NO" signs found in the deeper areas.
The balloons floating around the halls is probably a reference to Sonic's Schoolhouse, in which there was a minigame that involved popping balloons (which resemble the balloons seen here) to get items to open doors.
The balloons' sprites are not obscured when the fog event triggers. This may be a development oversight.
The 3D-modeled tree is first seen in the animated gif where Baldi gives a thumb up when Baldi's Basics Classic is downloaded 100,000 times. This was later used in the Full Game Early Demo.
The plants in the original Schoolhouse and the trees from the camping field trip contain some small transparent holes, due to the effect when removing backgrounds.
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