VEX Global Variables and Channels 1

What are global variables in VEX?

• Variables defined in functions
• Predefined variables available in any context
• User-defined variables
• Variables that control rendering

Answer explanation

Global variables in VEX are predefined and available in any context.

Which of these is a global variable in VEX?

• @P
• N
• Cd
• @N

Answer explanation

'N' is a global variable representing the surface normal.

How do you create a custom parameter in VEX?

• By declaring a global variable
• By using ch() function
• By creating a new node
• By writing a Python script

Answer explanation

The ch() function is used to reference custom parameters in VEX.

What does the ch() function do in VEX?

• Changes a variable
• Creates a channel reference
• Modifies global variables
• Accesses shader settings

Answer explanation

The ch() function creates a channel reference for custom parameters.

Which global variable holds point positions?

• @Cd
• P
• N
• @ptnum

Answer explanation

'P' is a global variable that holds point positions.

How do you access a custom float parameter in VEX?

• chf()
• ch()
• chv()
• chp()

Answer explanation

The ch() function is used for accessing custom parameters, including floats.

What is @ptnum in VEX?

• A predefined variable for the total number of points
• A global variable for the current point number
• A custom parameter
• A local variable for geometry attributes

Answer explanation

@ptnum is a global variable representing the current point number.

How can you use custom parameters to control geometry?

• By using Python scripts
• By linking parameters with ch()
• By writing shaders
• By modifying the SOP network

Answer explanation

Custom parameters are linked to geometry attributes via ch() in VEX.

What type of variable is P in VEX?

• Custom
• Global
• Local
• Temporary

Answer explanation

P is a global variable representing the position of points in VEX.

Which of these functions is used to access vector parameters in VEX?

• ch()
• chv()
• che()
• chn()

Answer explanation

The chv() function is used to access vector parameters in VEX.