Hi, i'm trying to put a Fur shader in my animation, but 3dgs gives me an error in this lines:

const half4x4 matWorldViewProj; ------ keyword unknown 'const'
const half4x4 matWorld; ------ keyword unknown 'const'
const half4x4 matWorldIT; ------ keyword unknown 'const'

And with the rest of the lines of the script :S
This is a HLSL script, so why this errors?