Expression Float

Overview

Evaluates a short formula written as text and outputs one number. It can consolidate a calculation that would require several math_op or math_func nodes into one, such as floor(x*4)/4. Use it to tidy a graph when numeric wiring becomes hard to read.

Usage tips

• A single expression is usually clearer for calculations that would need three or more numeric nodes. For one simple operation, math_op makes the intent more visible in the graph.
• You can use time / frame directly in an expression without connecting time_source. For example, sin(time * pi * 2) produces one sine-wave cycle.
• if(condition, a, b) replaces the numeric equivalent of compare + switch with one expression.
• The go-to pixel snap expression is floor(x * number_of_steps) / number_of_steps.

Related nodes

• math_op / math_func — node-based equivalents
• list_map — transform every list item with the same expression engine
• compare / switch — propagate a Bool condition to other types
• float_input — supply variables

Read this first

• The x, y, z, w, vec, and flag used here are not variables created in the variable panel.
• They are input pin names belonging to the Expression node itself.
• You can also enter x, y, z, w, vec_x, vec_y, and flag directly in the Inspector.
• To use a variable created in the variable panel, retrieve it with Variable Ref or a similar node and connect it to the corresponding input pin.
• When a value is connected to an input pin, that value takes priority over the Inspector value.
• Unconnected inputs are treated as follows:
  • x, y, z, w = 0
  • vec = [vec_x, vec_y]
  • flag = false

Available items

• Variables: x, y, z, w, vec, vx, vy, flag, time, frame, total_frames
• Operators: + - * / %, == != < <= > >=, && || !
• Functions: min, max, clamp, abs, floor, ceil, round, sign, sin, cos, tan, sqrt, pow, lerp, vec2, x, y, length, if

Common expressions

• x + y * 2
• sin(time * pi * 2)
• if(flag, x, y)
• length(vec) * 0.5

Detailed examples

Example 1: Simple addition

• Set x to 0.5.
• Set y to 2.
• Set expression = x + y * 2.

value = 4.5

Example 2: Leaving inputs unconnected

• Do not connect any inputs.
• Set expression = x + 1.

In this case, x is treated as 0.

value = 1

Example 3: Using time

• Set expression = sin(time * pi * 2).

As time changes from 0.0 to 1.0, the result completes one sine-wave cycle.

When to use it

• To write a small formula that does not justify arranging several numeric nodes
• To test an expression on its own before putting it in ListMap

Notes

• && / || skip the right side once the result is known, and if(condition, A, B) evaluates only the selected branch.
• Reversed clamp bounds are swapped, sign(0) = 0, and % is the Euclidean remainder in 0 <= result < |right operand|. As with the Math nodes, division or modulo by zero and sqrt of a negative value produce an error.
• This is not intended for long logic or operations with side effects.
• Version 1 is a lightweight escape hatch.
• While editing an expression, even an incomplete intermediate string is evaluated immediately, so an error may appear temporarily.