Don't get overwhelmed by the number and variety of BBs.

You probably will not use the majority of them.

Here is a very selective list of BBs that you are most likely to use for their related purposes. This cuts the list of BBs to about a fifth of what's available. As you study the BBs within Virtools, cross reference with this list to help narrow down choices or determine if you are doing something with more advanced needs. BBs that are in italics are a little more sophisticated than the others, but still fall into this basic list. Note the longest list is in the Logics category, as these have the most to do with programming logic - like conditional statements, loops, and number generation.

3D Transformations
Animation Play Animation 3D Entity designate an object's imported animation and the duration to play it
Basic Rotate User-defined axis and speed, must loop for continuous rotation
Set Euler Orientation set specific rotation value on X, Y, and Z angles
Set Position set specific X,Y,Z position
Translate user defined axis and distance, loop for continuous motion
Constraint Look At aligns X,Y,or Z axis of object to point at a target, loop for continuous aiming
Mimic make one object do the same as another object, but with a decay value
Object Keep On Floor V2 whatever is making the object move, it will stay on the declared floor objects
Curve Curve Follow make an object follow a curve as a path, over a given duration
Position on Curve user-defined position along the path, provides more control
Movement Move To easy way to move an object from its current position to a destination over time
Cameras
Montage Set As Active Camera Switch from one camera to another
Characters
Constraint Enhanced Character Keep On Floor whatever is making the character move, it will stay on the declared floor objects
Movement Character Controller basic way to invoke animations based on joystick messages
Character Go To makes character use walk animation to go to a user-defined destination
Unlimited Controller extensive custom control over character animation playback through messaging
Collisions
3D Entity Collision Detection a one-shot test to see if a target object has intersected with any obstacles
Object Slider restricts an object from passing through user-defined obstacles
Controllers
Joystick Joystick Waiter outputs and output values for all the joystick movements and buttons
Keyboard  Key Event activates on a single key down AND/OR key up
Switch On Key user-defined set of keys trigger multiple outputs, simultaneously too
Mouse Mouse Waiter settings allow detection of any mouse button or movement
Interface 
Fonts Create System Font sets up a font for use by other 2D or 3D text display BBs
Screen 2D Picking returns object under a 2D coordinate such as the mouse position
Text  2D Text needs Create System Font and a 2D Frame to display
Text Display doesn't need anything additional
Logics 
Attribute  Has Attribute any object can have a built-in or user-created attribute to read
Set Attribute an attribute is referred to by name and can be almost any data type
Calculator     Get Component extract the "X", "Y", or "Z" values independently
Identity set the value of a variable
Op Same as "Parameter Operators" but has Ins and Outs like other BBs
Random any data type can be output within a min and max range
Set Component put three components into X,Y,Z vector
Groups   Get Nearest In Group what is closest in 3D space to the referenced target object
Group Iterator loops through all the entities in a group as found in the level editor
Is In Group returns if true or not - Is the seleceted object in the designated group?
Interpolator Interpolator powerful means to blend between two values of any data type
Loops     Bezier Progression from one float value to another for a given time along a user-defined curve
Counter do loop for however many times you specify
Delayer pause for any duration
Linear Progression from one float value to another for a given time
Timer loops until the user-defined time runs out, unless restarted before times up
Message   Broadcast Message send a built-in or user-defined message to the entire system
Send Message send a built-in or user-defined message to a specified object
Wait Message listen for a message until it arrives - default is "on click"
Streaming        Binary Memory sets a boolean output to true or false depending on one of two inputs
Binary Switch if boolean is true then output on #1, otherwise on #2
Keep Active output continuously triggers until the reset input is activated
Nop means "No Operation". Handy for branching logic or watching links to debug
Parameter Selector output from a list of possible values based on which input is activated
Random Switch one of any number of outputs activated when the input is activated
Sequencer each time the input is activated the next output in sequence is activated
Switch On Parameter test an incoming value to see if it matches any user-defined values
Test  Proximity distance between 3D objects - true or false threshold and enter/exit threshold
Test if / else test with greater than, less than, equal to, >=, <=
Narratives 
Script Management Activate Script scripts don't have to be active when the scene starts. This will activate it
Deactivate Script If the car blew up, maybe it shouldn't be driving around any more
Particles 
ParticleSystem (Shape Type) ParticleSystem the most parameters you will see on any BB, and the settings as well
Sounds
Basic  Play Sound Instance best for playing sounds fully loaded in memory that can overlap each other
Wave Player best for playing continuous sound like music that streams from the hard drive
Visuals
Shadows Shadow Stencil of the various shadow systems, this is the easiest but also most cpu intensive
Show-Hide   Hide hide any object
Show show any object
Show Mouse Cursor hide the mouse cursor