Is it possible to extract the mathaccent tilde $\tilde{}$ to render on the baseline?

Question

I'm interested in the tilde symbol used for math accents. In the source2e it is defined as follows:

471 \DeclareMathAccent{\tilde}{\mathalpha}{operators}{"7E}

I want to mess around with the symbol alone. For example rotate, translate, scale, etc. (n.b. the symbol is not the same symbol as \sim). Besides doing something funky like using \raisebox on an empty tilde to get the symbol to render on the baseline, is there a way to call on the symbol alone?

I have tried creating a custom "\mytilde"

\DeclareMathSymbol {\mytilde} {\mathalpha} {operators} {"7E}

but the symbol is still floating above the baseline. Any advice is appreciated.

If my suspicions are correct, then the symbol may be constructed to have the "floating" behavior, and that I may have to resort to the funky method.

Answer 1

Yes, the space under the tilde is built into the underlying glyph, so some funk is required. Here, by not only applying a \raisebox, but by putting the result in a box, I can truncate the underhanging space that would otherwise be left over from the \raisebox.

\documentclass{article}
%\DeclareMathAccent{\tilde}{\mathalpha}{operators}{"7E}
\DeclareMathSymbol {\mytilde} {\mathalpha} {operators} {"7E}
\newcommand\bltilde{\setbox0=\hbox{\raisebox{-1.3ex}{$\mytilde$}}\dp0=0pt\relax\box0}
\begin{document}
\fboxsep=-\fboxrule
\fbox{\bltilde} x\bltilde
\end{document}

If it is needed to operate in the smaller math styles:

\documentclass{article}
\usepackage{scalerel}
%\DeclareMathAccent{\tilde}{\mathalpha}{operators}{"7E}
\DeclareMathSymbol {\mytilde} {\mathalpha} {operators} {"7E}
\newcommand\bltilde{\ThisStyle{\setbox0=\hbox{\raisebox{-1.3\LMex}{%
  $\SavedStyle\mytilde$}}\dp0=0pt\relax\box0}}
\begin{document}
\fboxrule=.1pt
\fboxsep=-\fboxrule
\fbox{\bltilde} x\bltilde

$x\bltilde \scriptstyle x\bltilde \scriptscriptstyle x\bltilde$
\end{document}