答案1
这是一个使用名为 的双参数宏的解决方案\ShiftDown
。第一个参数必须是长度——例如,3ex
或7mm
——并且是您希望在括号下方显示的文本。
\documentclass{article}
\usepackage{amsmath} % for '\underbrace' macro
\newcommand\ShiftDown[2]{\raisebox{-#1}{\upshape\scriptsize #2}}
\begin{document}
\[
\underbrace{x+2}_{\text{content}}
\underbrace{x+2}_{\ShiftDown{1.5ex}{content}}
\underbrace{x+2}_{\ShiftDown{3.0ex}{content}}
\underbrace{x+2}_{\ShiftDown{4.5ex}{content}}
\]
\end{document}
答案2
感谢 Bernard——https://tex.stackexchange.com/a/459154/197451
\documentclass[a4paper]{article}
\usepackage{mathtools}
\usepackage{bigstrut}
\begin{document}
\begin{equation}\label{eq:reprojection_error_final}
f=\min_{\hat{P}^i, \hat{X}_j}
\sum_{ij} \Bigl[\underbracket[1.5pt][8pt]{d(\hat{P}^i \hat{X}_j, x^i_j)}_{\text{Projektionsdiff.}} + \underbracket[1.5pt][8pt]{d(L_k^m - L_{k+1}^m ,\hat{X}_k^m - \hat{X}_{k+1}^m)}_{\text{3D-Punkt-Differenz}} + \underbracket[1.5pt][8pt]{d(\hat{X}_0, 0)}_{\text{Ursprungsdiff.}}\Bigr]^2
\end{equation}
\begin{equation}\label{eq:reprojection_error_final}
f=\min_{\hat{P}^i, \hat{X}_j}
\sum_{ij} \Bigl[\underbracket[1.5pt][8pt]{\bigstrut[b]d(\hat{P}^i \hat{X}_j, x^i_j)}_{\text{Projektionsdiff.}} + \underbracket[1.5pt][8pt]{\bigstrut[b]d(L_k^m - L_{k+1}^m ,\hat{X}_k^m - \hat{X}_{k+1}^m)}_{\text{3D-Punkt-Differenz}} + \underbracket[1.5pt][8pt]{\bigstrut[b]d(\hat{X}_0, 0)}_{\text{\clap{Ursprungsdiff.}}}\Bigr]^2
\end{equation}
\end{document}