[Port] [6000.3] docg-7313: Explain how a lower dimension T input value is mapped to the components of A and B

Author: ocarrere

Packages/com.unity.shadergraph/Documentation~/Lerp-Node.md

@@ -4,16 +4,26 @@
 
 Returns the result of linearly interpolating between input **A** and input **B** by input **T**.
 
-For example, when the value of input **T** is 0 the return value is equal to the value of input **A**, when it is 1 the return value is equal to the value of input **B** and when it is 0.5 the return value is the midpoint of the two inputs **A** and **B**.
+Unity calculates the output as:
+
+A + T × (B − A)
+
+The value of input **T** acts as a weight factor applied to the difference between **B** and **A**:
+
+- When **T** is `0`, the output equals **A**.
+- When **T** is `1`, the output equals **B**.
+- When **T** is `0.5`, the output is the midpoint between **A** and **B**.
+
+The Lerp node uses Dynamic Vector slots, so **A**, **B**, and **T** always resolve to the same component count, which matches the smallest connected vector (larger vectors truncate). Scalars promote to the resolved size by duplicating their value across components.
 
 ## Ports
 
 | Name | Direction | Type           | Description |
 |:-----|:----------|:---------------|:------------|
-| A    | Input     | Dynamic Vector | First input value  |
-| B    | Input     | Dynamic Vector | Second input value |
-| T    | Input     | Dynamic Vector | Time value. Typical range: 0 to 1. Though you can use values outside of this range they may cause unpredictable results. |
-| Out  | Output    | Dynamic Vector | Output value |
+| **A**    | Input     | Dynamic Vector | First input value  |
+| **B**    | Input     | Dynamic Vector | Second input value |
+| **T**    | Input     | Dynamic Vector | Time value. Typical range: 0 to 1. Though you can use values outside of this range they may cause unpredictable results. |
+| **Out**  | Output    | Dynamic Vector | Output value |
 
 ## Generated Code Example
 

Packages/com.unity.shadergraph/Documentation~/Node.md

@@ -40,3 +40,5 @@ Right clicking on a **Node** will open a context menu. This menu contains many o
 **Nodes** interact with the Shader Graph Window's Color Modes. Colors are displayed on nodes underneath the text on the node title bar. See [Color Modes](Color-Modes.md) for more information on available colors for nodes.
 
 <image>
+
+Unity applies each component of T as a weight factor to each component to A and B. If T has fewer components than A and B, Unity casts T to the required number of components. Unity copies the values of the original components of T to the added components.