SPIR-V Built-In
InstanceIndex
Index of an instance
InstanceIndex
Decorating a variable in a vertex shader with the InstanceIndex
built-in decoration will make that variable contain the index of the
instance that is being processed by the current vertex shader invocation.
InstanceIndex
begins at the firstInstance
parameter to
vkCmdDraw or vkCmdDrawIndexed or at the firstInstance
member of a structure consumed by vkCmdDrawIndirect or
vkCmdDrawIndexedIndirect.
Valid Usage
VUID-InstanceIndex-InstanceIndex-04263
The InstanceIndex
decoration must be used only within the
Vertex
Execution
Model
VUID-InstanceIndex-InstanceIndex-04264
The variable decorated with InstanceIndex
must be declared using
the Input
Storage
Class
VUID-InstanceIndex-InstanceIndex-04265
The variable decorated with InstanceIndex
must be declared as a
scalar 32-bit integer value