Test/Library/PackageCache/com.unity.shadergraph@8b7e693cdbfe/Documentation~/Expression-Node.md

Expression node

Use the Expression node to specify a complex mathematical expression as a string instead of using multiple Math nodes.

Note

Unity injects the provided expression into the shader code as HLSL and validates it through preview shader compilation. Ensure that the provided expression conforms to HLSL syntax.

Input ports

The number and type of input ports automatically adjust to the values of the node controls. Unity adds an input port for each variable in the expression in the text field.

Output port

Name	Type	Description
Out	Depends on the selected Type in the node controls.	The value resulting from the expression specified in the text field.

Controls

Name	Description
Type	Specifies the data type to use for all input and output ports of the node. The options are: Vector 1 Vector 2 Vector 3 Vector 4
(Text field)	Use this field to specify the mathematical expression. The field supports the following: Math operators: +, -, *, /, and parentheses. HLSL intrinsic functions: for example, frac and saturate. Vector swizzling: for example, a.xw. Vector construction: float2(x, y).

Example

If you specify the expression:

a + b * c / 2

• Unity adds three input ports to the node: A, B, and C.
• If you input 1, 2, and 10, the node calculates 1 + 2 * 10 / 2 and outputs the result to the Out port.

Note: If you use Shader Graph math nodes instead, the example requires three separate nodes: Divide, Multiply, and Add.

Additional resources

[!includenodes-example-samples]