我想在不改变颜色图的情况下，沿 x 变量降低图片管的不透明度。这是我的代码：
\documentclass[tikz]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.8}
\usepackage{tikz}
\usetikzlibrary{shadows,
positioning,
decorations,
decorations.text,
decorations.markings,
decorations.pathmorphing,
calc,
fit,
intersections,
shapes,
patterns,
angles,
quotes,}
\begin{document}
\begin{tikzpicture}
\begin{axis}[
axis lines=center,
axis equal image,
view={15}{30},
xlabel={$x$},
xtick=\empty,
xlabel style={anchor=west},
ylabel={$y$},
ytick=\empty,
ylabel style={anchor=west},
zlabel={$\vec{\omega}$},
ztick=\empty,
zlabel style={anchor=south},
domain=0.15:0.4,
y domain=0:2*pi,
xmin=-0.1, xmax=0.65,
ymin=-0.1, ymax=0.6,
zmin=-0.1, zmax=0.4,
mesh/interior colormap={blackgreen}{
color=(white!70!gray) color=(black!50!gray)},
colormap={blueblack}{color=(blue) color=(cyan)},
samples=5,
samples y=15,
%z buffer=sort,
]
\coordinate (0) at (axis cs:0,0,0);
\coordinate (x) at (axis cs:1,0,0);
\coordinate (a) at (axis cs:0.43,0.46,0.043);
\coordinate (a1) at (axis cs:0.55,0.58,0.043);
\coordinate (b) at (axis cs:0.46,0.43,-0.043);
\coordinate (b1) at (axis cs:0.55,0.52,-0.043);
\addplot3[black,fill=white,fill opacity=.5] ({0.07*cos(deg(y))},{0.07*sin(deg(y))},{0});
\addplot3[mark=none,surf,
%point meta rel=per plot,
%point meta=x,
%opacity=(1000/\pgfplotspointmetatransformed),
y domain=-2*pi/3:pi/3] (
{x+0.035*(-cos(deg(y))+1)},
{x+0.035*(+cos(deg(y))+1)},
{0.05*sin(deg(y))});
\node[circle,inner sep=1pt,shade,ball color=red!60!white,white,scale=1.3]
(m) at (axis cs:0.3,0.3,0) {$m$};
\draw[red,-stealth] (0) -- (m) node[black,midway,above] {$r$};
%\addplot3[black,surf,opacity=.1,y domain=pi/3:4*pi/3] (
%{x+0.035*(-cos(deg(y))+1)},
%{x+0.035*(+cos(deg(y))+1)},
%{0.05*sin(deg(y))});
\pic[pic text=$\omega t$,
-stealth,
thick,
draw=orange,
angle eccentricity=0.75,
angle radius=1.1cm]
{angle=x--0--m};
\draw[dashed] (a) -- (a1);
\draw[dashed] (b) -- (b1);
\end{axis}
\end{tikzpicture}
\end{document}
答案1
你可以作弊并在顶部绘制一个褪色的矩形。
\documentclass[tikz]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.16}
\usepackage{tikz}
\usetikzlibrary{shadows,
positioning,
decorations,
decorations.text,
decorations.markings,
decorations.pathmorphing,
calc,
fit,
intersections,
shapes,
patterns,
angles,
quotes,}
\begin{document}
\begin{tikzpicture}
\begin{axis}[
axis lines=center,
axis equal image,
view={15}{30},
xlabel={$x$},
xtick=\empty,
xlabel style={anchor=west},
ylabel={$y$},
ytick=\empty,
ylabel style={anchor=west},
zlabel={$\vec{\omega}$},
ztick=\empty,
zlabel style={anchor=south},
domain=0.15:0.4,
y domain=0:2*pi,
xmin=-0.1, xmax=0.65,
ymin=-0.1, ymax=0.6,
zmin=-0.1, zmax=0.4,
mesh/interior colormap={blackgreen}{
color=(white!70!gray) color=(black!50!gray)},
colormap={blueblack}{color=(blue) color=(cyan)},
samples=5,
samples y=15,
%z buffer=sort,
]
\coordinate (0) at (axis cs:0,0,0);
\coordinate (x) at (axis cs:1,0,0);
\coordinate (a) at (axis cs:0.43,0.46,0.043);
\coordinate (a1) at (axis cs:0.55,0.58,0.043);
\coordinate (b) at (axis cs:0.46,0.43,-0.043);
\coordinate (b1) at (axis cs:0.55,0.52,-0.043);
\addplot3[black,fill=white,fill opacity=.5] ({0.07*cos(deg(y))},{0.07*sin(deg(y))},{0});
\addplot3[mark=none,surf,
point meta rel=per plot,
% point meta=-x-y,
% opacity=(1000/(\pgfplotspointmetatransformed+1)),
y domain=-2*pi/3:pi/3] (
{x+0.035*(-cos(deg(y))+1)},
{x+0.035*(+cos(deg(y))+1)},
{0.05*sin(deg(y))});
\fill[path fading=west,white]
(axis cs:{0.1+0.035*(-cos(deg(-2*pi/3))+1)},{0.05+0.035*(-cos(deg(-2*pi/3))+1)},{0.05*sin(deg(-2*pi/3))})
--
(axis cs:{0.45+0.035*(-cos(deg(-2*pi/3))+1)},{0.35+0.035*(-cos(deg(-2*pi/3))+1)},{0.05*sin(deg(-2*pi/3))})
--
(axis cs:{0.4+0.035*(-cos(deg(2*pi/3))+1)},{0.45+0.035*(-cos(deg(2*pi/3))+1)},{0.05*sin(deg(2*pi/3))})
--
(axis cs:{0.1+0.035*(-cos(deg(2*pi/3))+1)},{0.15+0.035*(-cos(deg(2*pi/3))+1)},{0.05*sin(deg(2*pi/3))})
-- cycle;
\node[circle,inner sep=1pt,shade,ball color=red!60!white,white,scale=1.3]
(m) at (axis cs:0.3,0.3,0) {$m$};
\draw[red,-stealth] (0) -- (m) node[black,midway,above] {$r$};
%\addplot3[black,surf,opacity=.1,y domain=pi/3:4*pi/3] (
%{x+0.035*(-cos(deg(y))+1)},
%{x+0.035*(+cos(deg(y))+1)},
%{0.05*sin(deg(y))});
\pic[pic text=$\omega t$,
-stealth,
thick,
draw=orange,
angle eccentricity=0.75,
angle radius=1.1cm]
{angle=x--0--m};
\draw[dashed] (a) -- (a1);
\draw[dashed] (b) -- (b1);
\end{axis}
\end{tikzpicture}
\end{document}
