VkGeometryInstanceFlagBitsKHR

Possible values of flags in the instance modifying the behavior of that instance are:

typedef enum VkGeometryInstanceFlagBitsKHR {
    VK_GEOMETRY_INSTANCE_TRIANGLE_FACING_CULL_DISABLE_BIT_KHR = 0x00000001,
    VK_GEOMETRY_INSTANCE_TRIANGLE_FLIP_FACING_BIT_KHR = 0x00000002,
    VK_GEOMETRY_INSTANCE_FORCE_OPAQUE_BIT_KHR = 0x00000004,
    VK_GEOMETRY_INSTANCE_FORCE_NO_OPAQUE_BIT_KHR = 0x00000008,
    VK_GEOMETRY_INSTANCE_TRIANGLE_FRONT_COUNTERCLOCKWISE_BIT_KHR = VK_GEOMETRY_INSTANCE_TRIANGLE_FLIP_FACING_BIT_KHR,
} VkGeometryInstanceFlagBitsKHR;

or the equivalent

#define VkGeometryInstanceFlagBitsNV VkGeometryInstanceFlagBitsKHR

• VK_GEOMETRY_INSTANCE_TRIANGLE_FACING_CULL_DISABLE_BIT_KHR disables face culling for this instance.
• VK_GEOMETRY_INSTANCE_TRIANGLE_FLIP_FACING_BIT_KHR indicates that the facing determination for geometry in this instance is inverted. Because the facing is determined in object space, an instance transform does not change the winding, but a geometry transform does.
• VK_GEOMETRY_INSTANCE_FORCE_OPAQUE_BIT_KHR causes this instance to act as though VK_GEOMETRY_OPAQUE_BIT_KHR were specified on all geometries referenced by this instance. This behavior can be overridden by the SPIR-V NoOpaqueKHR ray flag.
• VK_GEOMETRY_INSTANCE_FORCE_NO_OPAQUE_BIT_KHR causes this instance to act as though VK_GEOMETRY_OPAQUE_BIT_KHR were not specified on all geometries referenced by this instance. This behavior can be overridden by the SPIR-V OpaqueKHR ray flag.

VK_GEOMETRY_INSTANCE_FORCE_NO_OPAQUE_BIT_KHR and VK_GEOMETRY_INSTANCE_FORCE_OPAQUE_BIT_KHR must not be used in the same flag.