SPIR-V Built-In

RayTminKHR

Minimum T value of a ray
RayTminKHR

A variable decorated with the RayTminKHR decoration will contain the parametric tmin value of the ray being processed. The value is independent of the space in which the ray origin and direction exist. The value is the parameter passed into the pipeline trace ray instruction.

The tmin value remains constant for the duration of the ray query.

Valid Usage

VUID-RayTminKHR-RayTminKHR-04351

The RayTminKHR decoration must be used only within the IntersectionKHR, AnyHitKHR, ClosestHitKHR, or MissKHR Execution Model

VUID-RayTminKHR-RayTminKHR-04352

The variable decorated with RayTminKHR must be declared using the Input Storage Class

VUID-RayTminKHR-RayTminKHR-04353

The variable decorated with RayTminKHR must be declared as a scalar 32-bit floating-point value