Rasagar/Library/PackageCache/com.unity.shadergraph/Documentation~/Screen-Position-Node.md

Screen Position Node

Description

Provides access to the screen position of the mesh vertex or fragment. The X and Y values represent the horizontal and vertical positions respectively. Use the Mode dropdown control to select the mode of the output value. The available modes are as follows:

• Default - Returns X and Y values that represent the normalized Screen Position. The normalized Screen Position is the Screen Position divided by the clip space position W component. The X and Y value ranges are between 0 and 1 with position float2(0,0) at the lower left corner of the screen. The Z and W values aren't used in this mode, so they're always 0.

• Raw - Returns the raw Screen Position values, which are the Screen Position values before the clip space position W component is divided out. Position float2(0,0) is at the lower left corner of the screen. This mode is useful for projection.

• Center - Returns X and Y values that represent the normalized Screen Position offset so position float2(0,0) is at the center of the screen. The range of the X and Y values is –1 to 1. The Z and W values aren't used in this mode, so they're always 0.

• Tiled - Returns Screen Position offset so position float2(0,0) is at the center of the screen and tiled using frac.

• Pixel - Returns Screen Position in terms of the actual pixel width and height values of the screen. In this mode, position float2(0,0) is at the lower left corner of the screen. Whereas the range of Default mode is always 0 to 1, the range of Pixel mode depends on the screen resolution. The Z and W values aren't used in this mode, so they're always 0.

Ports

Name	Direction	Type	Binding	Description
Out	Output	Vector 4	None	Get the Screen Position of the mesh.

Controls

Name	Type	Options	Description
Mode	Dropdown	Default, Raw, Center, Tiled, Pixel	Select which coordinate space to use for the Screen Position output.

Generated Code Example

The following code examples represent one possible outcome for each mode.

Default

float4 Out = float4(IN.NDCPosition.xy, 0, 0);

Raw

float4 Out = IN.ScreenPosition;

Center

float4 Out = float4(IN.NDCPosition.xy * 2 - 1, 0, 0);

Tiled

float4 Out = frac(float4((IN.NDCPosition.x * 2 - 1) * _ScreenParams.x / _ScreenParams.y, IN.{0}.y * 2 - 1, 0, 0));

Pixel

float4 Out = float4(IN.PixelPosition.xy, 0, 0);