Position(3)

Name

Position - Vertex position

Description

Position

Decorating a variable with the Position built-in decoration will make that variable contain the position of the current vertex. In the last pre-rasterization shader stage, the value of the variable decorated with Position is used in subsequent primitive assembly, clipping, and rasterization operations.

When Position decorates a variable in the Input Storage Class, it contains the data written to the output variable decorated with Position from the previous shader stage.
Valid Usage

  • VUID-Position-Position-04318
    The Position decoration must be used only within the MeshEXT, MeshNV, Vertex, TessellationControl, TessellationEvaluation, or Geometry Execution Model

  • VUID-Position-Position-04319
    The variable decorated with Position within the MeshEXT, MeshNV, or Vertex Execution Model must be declared using the Output Storage Class

  • VUID-Position-Position-04320
    The variable decorated with Position within the TessellationControl, TessellationEvaluation, or Geometry Execution Model must not be declared using a Storage Class other than Input or Output

  • VUID-Position-Position-04321
    The variable decorated with Position must be declared as a four-component vector of 32-bit floating-point values

See Also

No cross-references are available

Document Notes

For more information, see the Vulkan Specification (NOTE: cannot determine Specification page containing this refpage).

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.