How access to BLENDWEIGHTS and BLENDINDICES

In 2019.1 Shaders: Added support for BLENDWEIGHTS and BLENDINDICES semantics in vertex shaders.

but how we can access to that data in vertex shader?

i try do so:

struct vertex
{
float4 vertex : POSITION; // The vertex position in model space.
...
float4 weights : BLENDWEIGHT;
float4 idx : BLENDINDICES;
};

but data is empty...

 

up

 

float4 weights : BLENDWEIGHTS;
int4 idx : BLENDINDICES;

 

Has to be uint4 on metal

 

Man, you saved my day!