problem with fadings and pic

Question

I try to generate several copies of a faded text using the PG 3.0 pic feature but something with the placement went wrong. Only the one at the origin is drawn.

Here is what I have done:

\documentclass[varwidth,margin=5mm]{standalone} 
\usepackage{tikz}
\usetikzlibrary{fadings}

\tikzset{
   myPic/.pic={
  \begin{tikzfadingfrompicture}[name = fading letter]
    \node[text = transparent!0, inner xsep = 0pt, outer xsep = 0pt] {test text};
  \end{tikzfadingfrompicture}
    \node[inner sep = 0pt, outer sep = 0pt] (textnode) {\phantom{test text}}; 
    \shade[path fading = fading letter, left color = blue, right color = green, fit fading = false, opacity=0.5] (textnode.south west) rectangle (textnode.north east);% 
   }
}

\begin{document} 
\begin{tikzpicture}
  \pic at (0,0)    {myPic};

  \pic at (0,2)    {myPic};
\end{tikzpicture}
\end{document}

Any help to solve it is highly welcome.

Answer 1

You need to also shift the fading with fading transform. I added

fading transform={shift={(textnode)}}

to get

\documentclass[varwidth,margin=5mm]{standalone} 
\usepackage{tikz}
\usetikzlibrary{fadings}

\tikzset{
   myPic/.pic={
  \begin{tikzfadingfrompicture}[name = fading letter]
    \node[text = transparent!0, inner xsep = 0pt, outer xsep = 0pt] {test text};
  \end{tikzfadingfrompicture}
    \node[inner sep = 0pt, outer sep = 0pt] (textnode) {\phantom{test text}}; 
    \shade[path fading = fading letter, left color = blue,
     right color = green, fit fading = false, opacity=0.5,
     fading transform={shift={(textnode)}}] (textnode.south west) rectangle (textnode.north east);% 
   }
}

\begin{document} 
\begin{tikzpicture}
  \pic at (0,0)    {myPic};

  \pic at (0,2)    {myPic};
\end{tikzpicture}
\end{document}