2.6 KiB
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 usingfrac. -
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);