在 tikz 中使用座標時輸出影像不同

Question

在 tikz-3dplot 中使用命名的 v/s 原始座標時，我得到不同的輸出影像。有沒有辦法列印出座標的值來幫助調試或檢查任何日誌檔案。下面的最小範例：

\documentclass{standalone}
\usepackage{tikz}
\usepackage{tikz-3dplot}
\usepackage{calc}

\begin{document}

    \tdplotsetmaincoords{70}{100}%right hand
    \begin{tikzpicture}[scale=2]
        \def\xmax{2}
        \def\ymax{2}
        \def\dz{0.2}
        \coordinate (M) at (0.5*\xmax,0.5*\ymax,0);
        \draw[fill=green!40!white, opacity = 0.5,tdplot_main_coords]
        ({0},{0},{0}) to [out=30,in=200]
        ({0},{\ymax},{0}) to
        ({\xmax},{\ymax},{0}) to[out=200,in=30]
        ({\xmax},{0},{0}) to
        ({0},{0},{-\dz}) to
         (M) to
        (0,0,0);
        \end{tikzpicture}

    \tdplotsetmaincoords{70}{100}%right hand
    \begin{tikzpicture}[scale=2]
        \def\xmax{2}
        \def\ymax{2}
        \def\dz{0.2}
        \draw[fill=green!40!white, opacity = 0.5,tdplot_main_coords]
        ({0},{0},{0}) to [out=30,in=200]
        ({0},{\ymax},{0}) to
        ({\xmax},{\ymax},{0}) to[out=200,in=30]
        ({\xmax},{0},{0}) to
        ({0},{0},{-\dz}) to
         (0.5*\xmax,0.5*\ymax,0) to
        (0,0,0);
        \end{tikzpicture}

\end{document}

Answer 1

tdplot_main_coords您在定義符號座標時沒有使用M。如果你更換

\coordinate (M) at (0.5*\xmax,0.5*\ymax,0);

經過

\path[tdplot_main_coords] (0.5*\xmax,0.5*\ymax,0) coordinate (M);

兩個結果都匹配。

\documentclass{standalone}
\usepackage{tikz}
\usepackage{tikz-3dplot}

\begin{document}

    \tdplotsetmaincoords{70}{100}%right hand
    \begin{tikzpicture}[scale=2]
        \def\xmax{2}
        \def\ymax{2}
        \def\dz{0.2}
        \path[tdplot_main_coords] (0.5*\xmax,0.5*\ymax,0) coordinate (M);
        \draw[fill=green!40!white, opacity = 0.5,tdplot_main_coords]
        ({0},{0},{0}) to [out=30,in=200]
        ({0},{\ymax},{0}) to
        ({\xmax},{\ymax},{0}) to[out=200,in=30]
        ({\xmax},{0},{0}) to
        ({0},{0},{-\dz}) to
         (M) to
        (0,0,0);
        \end{tikzpicture}

    \tdplotsetmaincoords{70}{100}%right hand
    \begin{tikzpicture}[scale=2]
        \def\xmax{2}
        \def\ymax{2}
        \def\dz{0.2}
        \draw[fill=green!40!white, opacity = 0.5,tdplot_main_coords]
        ({0},{0},{0}) to [out=30,in=200]
        ({0},{\ymax},{0}) to
        ({\xmax},{\ymax},{0}) to[out=200,in=30]
        ({\xmax},{0},{0}) to
        ({0},{0},{-\dz}) to
         (0.5*\xmax,0.5*\ymax,0) to
        (0,0,0);
        \end{tikzpicture}

\end{document}

此calc庫由 自動加載tikz-3dplot，可讓您比較命名節點/座標的螢幕座標。非官方圖書館3dtools允許您檢索用於定義節點/座標的座標，但此時不儲存定義它們的座標系的資訊。