--- layout: stdlib-reference --- # GetAttributeAtVertex ## Description Get the value of a vertex attribute at a specific vertex. The GetAttributeAtVertex() function can be used in a fragment shader to get the value of the given attribute at the vertex of the primitive that corresponds to the given vertexIndex. Note that the attribute must have been a declared varying input to the fragment shader with the nointerpolation modifier. This function can be applied to scalars, vectors, and matrices of built-in scalar types. ## Signature

T GetAttributeAtVertex<T>(
    T attribute,
    uint vertexIndex)
    where T : __BuiltinType;

vector<T, N> GetAttributeAtVertex<T, N:int>(
    vector<T, N> attribute,
    uint vertexIndex)
    where T : __BuiltinType;

matrix<T, N, M> GetAttributeAtVertex<T, N:int, M:int>(
    matrix<T, N, M> attribute,
    uint vertexIndex)
    where T : __BuiltinType;

## Generic Parameters #### T: \_\_BuiltinType #### N : int #### M : int ## Parameters #### attribute : [T](getattributeatvertex-03ce.html#typeparam-T) #### vertexIndex : uint #### attribute : [vector](../types/vector/index.html)\<[T](../types/vector/index.html#typeparam-T), [N](../types/vector/index.html#decl-N)\> #### attribute : [matrix](../types/matrix/index.html)\<[T](../types/matrix/t-0.html), [N](../types/matrix/index.html#decl-N), [M](../types/matrix/index.html#decl-M)\> ## Availability and Requirements Defined for the following targets: #### hlsl Available in `fragment` stage only. #### glsl Available in `fragment` stage only. #### spirv Available in `fragment` stage only. Requires capability: `spvFragmentBarycentricKHR`.