[Tex/LaTex] Smooth curved arrow through multiple nodes tikz (beamer)

beamertikz-arrowstikz-pgf

I'm trying to draw a curved arrow that passes through multiple nodes. This is for a beamer presentation. The idea of the frame is to pose the audience a question, tell them the answer, and then gradually go through a roadmap of the steps involved as follows:

I have three questions:

How to draw the blue arrow (more aesthetically pleasing)? By this, I mean, smaller arrow head, arrow should be incident onto the 'Answer' node. And the nodes should be "above" the arrow, as in, the arrow should be "sent behind" the nodes.
How to reveal a part of the arrow along with the stops along the roadmap. i.e, (part of arrow+Stop 1+Comment 1) appear on first click (slide 2).
Reveal the 'question' and 'answer' first, then the roadmap. But currently the positioning of the 'answer' is relative to the roadmap and beamer doesn't reveal it until the end. What am I doing wrong here?

I am looking to move forward with minimum code-disruption. Thank you. A MWE is attached.

\documentclass[usenames, dvipsnames]{beamer}
\usepackage{tikz}
\usepackage{amsmath}
\usetikzlibrary{automata,fit, backgrounds,shapes,arrows,calc,positioning}

\begin{document}

% Define block styles
\tikzstyle{block} = [rectangle, draw, fill=blue!20, 
    text width=5em, text centered, rounded corners, minimum height=4em]
\tikzstyle{wideblock} = [rectangle, draw, fill=blue!20, 
    text width=8em, text centered, rounded corners, minimum height=4em]
\tikzstyle{greenblock} = [rectangle, draw, fill=ForestGreen!20, 
    text width=8em, text centered, rounded corners, minimum height=4em]
\tikzstyle{plainblock} = [rectangle, draw, fill=blue!05, 
    text width=8em, text centered, rounded corners, minimum height=4em]
\tikzstyle{line} = [draw, -latex']

\begin{frame}{How we got to the answer}
\resizebox{0.8\linewidth}{!}{%
\begin{tikzpicture}[node distance = 7cm, auto]
\linespread{1}
\node[wideblock,text width=16em](main_ques){Question?};
%first stop along the road-map
\onslide<2->\node[plainblock, yshift=-1cm, right of = main_ques](map1){Stop 1};
\onslide<2->\node[plainblock, right of = map1](map1_comment){Comment 1}; 
\onslide<2->\path[line](map1) -- (map1_comment);
%second stop along the road-map
\onslide<3->\node[plainblock, yshift=-3cm, right of = map1, node distance = 2cm](map2){Stop 2};
\onslide<3->\node[plainblock, right of = map2](map2_comment){Comment 2}; 
\onslide<3->\path[line](map2) -- (map2_comment);
%third stop along the road-map
\onslide<4->\node[plainblock, yshift=-3cm, node distance = 2cm, right of = map2](map3){Stop 3};
\onslide<4->\node[plainblock, right of = map3](map3_comment){Comment 3}; 
\onslide<4->\path[line](map3) -- (map3_comment);
%fourth stop along the road-map
\onslide<5->\node[plainblock,yshift=-1cm, node distance = 2cm, below of = map3](map4){Stop 4};
\onslide<5->\node[plainblock, right of = map4](map4_comment){Comment 4}; 
\onslide<5->\path[line](map4) -- (map4_comment);
%fifth stop along the road-map
\onslide<6->\node[plainblock,yshift=-3cm, node distance = 2cm, left of = map4](map5){This is a really really long sentence};
\onslide<6->\node[plainblock, right of = map5](map5_comment){comment 5}; 
\onslide<6->\path[line](map5) -- (map5_comment);
%Sixth stop along the road-map
\onslide<7->\node[plainblock,yshift=-3cm, node distance = 2cm, left of = map5](map6){Stop 5};
\onslide<7->\node[plainblock, right of = map6, text width = 12em](map6_comment){This is a very long comment that requires a bigger text box}; 
\onslide<7->\path[line](map6) -- (map6_comment);
%This is the answer that should appear on the first slide itself.
\node[greenblock, yshift=-1cm, left of = map6](ans){Answer};
\path[line](main_ques) -- (ans);
\end{tikzpicture}}
\end{frame}
\end{document}

Best Answer

The current code doesn't draw an arrow for me at all. I've updated the deprecated syntax (mostly - annotated elsewhere), added a curve with hobby, corrected the overlay specifications so that they are scoped properly and created overlay-specific clippings for the new arrow, which is drawn behind the nodes with a smaller arrow head than that pictured. Adjust to suit.

\documentclass[usenames, dvipsnames]{beamer}
\usepackage{tikz}
\usepackage{amsmath}
\usetikzlibrary{arrows,calc,backgrounds,positioning,hobby,arrows.meta}% arrows is deprecated, too

\begin{document}

% Define block styles
\tikzset{% \tikzstyle is deprecated
  block/.style = {rectangle, draw, fill=blue!20, text width=5em, text centered, rounded corners, minimum height=4em},
  wideblock/.style = {rectangle, draw, fill=blue!20, text width=8em, text centered, rounded corners, minimum height=4em},
  greenblock/.style = {rectangle, draw, fill=ForestGreen!20, text width=8em, text centered, rounded corners, minimum height=4em},
  plainblock/.style = {rectangle, draw, fill=blue!05, text width=8em, text centered, rounded corners, minimum height=4em},
  line/.style = {draw, -latex'},
}

\begin{frame}{How we got to the answer}
  \resizebox{0.8\linewidth}{!}{%
    \begin{tikzpicture}[node distance = 7cm, auto]
      \linespread{1}
      \node[wideblock,text width=16em](main_ques){Question?};
      %first stop along the road-map
      \onslide<2->{\node[plainblock, yshift=-1cm, right of = main_ques](map1){Stop 1};
        \node[plainblock, right of = map1](map1_comment){Comment 1};
        \path[line](map1) -- (map1_comment);}
      %second stop along the road-map
      \onslide<3->{\node[plainblock, yshift=-3cm, right of = map1, node distance = 2cm](map2){Stop 2};
        \node[plainblock, right of = map2](map2_comment){Comment 2};
        \path[line](map2) -- (map2_comment);}
      %third stop along the road-map
      \onslide<4->{\node[plainblock, yshift=-3cm, node distance = 2cm, right of = map2](map3){Stop 3};
        \node[plainblock, right of = map3](map3_comment){Comment 3};
        \path[line](map3) -- (map3_comment);}
      %fourth stop along the road-map
      \onslide<5->{\node[plainblock,yshift=-1cm, node distance = 2cm, below of = map3](map4){Stop 4};
        \node[plainblock, right of = map4](map4_comment){Comment 4};
        \path[line](map4) -- (map4_comment);}
      %fifth stop along the road-map
      \onslide<6->{\node[plainblock,yshift=-3cm, node distance = 2cm, left of = map4](map5){This is a really really long sentence};
        \node[plainblock, right of = map5](map5_comment){comment 5};
        \path[line](map5) -- (map5_comment);}
      %Sixth stop along the road-map
      \onslide<7->{\node[plainblock,yshift=-3cm, node distance = 2cm, left of = map5](map6){Stop 5};
        \node[plainblock, right of = map6, text width = 12em](map6_comment){This is a very long comment that requires a bigger text box};
        \path[line](map6) -- (map6_comment);}
      %This is the answer that should appear on the first slide itself.
      \node[greenblock, yshift=-1cm, left of = map6](ans){Answer};
      \path[line](main_ques) -- (ans);
      \begin{scope}[on background layer]
        \onslide<2->
        \only<2>{\clip (current bounding box.north west) rectangle (map1.south east);}
        \only<3>{\clip (current bounding box.north west) rectangle (map2.south east);}
        \only<4>{\clip (current bounding box.north west) rectangle (map3.south east);}
        \only<5>{\clip (current bounding box.north west) rectangle (map4.south east);}
        \only<6>{\clip (current bounding box.north west) rectangle (map5.south -| current bounding box.east);}
        \only<7>{\clip (current bounding box.north west) rectangle (map6.south -| current bounding box.east);}
        \only<8>{\clip (current bounding box.north west) rectangle (current bounding box.south east);}
        \draw [blue!50!cyan, line width=1.5pt, -{Triangle[width=2.5mm,length=2.5mm]}] (main_ques.east) to [curve through=($(map1)!.5!(map2)$) ($(map3)!.5!(map4)$) ($(map5)!.5!(map6)$)] (ans.east);
      \end{scope}
    \end{tikzpicture}%
  }
\end{frame}
\end{document}

Note to editors: Please do NOT convert my image to, or replace it with, a GIF. If I wanted it to be animated, I'd have created one myself. Thank you.

Related Solutions

[Tex/LaTex] Rotate a node but not its content: the case of the ellipse decoration

The source of the difficulty is that ellipses are constructed in a particular way in TikZ. They are paths that start from the x-axis and proceed counter-clockwise around their centre. The vast majority of the time, the exact parametrisation doesn't matter. You appear to have found the one situation where it does!

In the actual question, you only want to be able to mirror the ellipse, and so draw it starting from the negative x-axis (the title of the question suggests a more flexible approach). That's actually not too hard since we can exploit the symmetry of the ellipse. The key is to provide it with a negative x-radius, since then it will start from the negative x-axis (and proceed clockwise, but we could correct for that by negating the y-radius as well). To do this, we interrupt the call from the node shape to the drawing command and flip the sign of the x-radius. The simplest way to do this is to redefine the \pgfpathellipse macro to do the negation and then call the original macro. The following code does this.

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{decorations,shapes,decorations.markings}
\makeatletter
\let\origpgfpathellipse=\pgfpathellipse
\def\revpgfpathellipse#1#2#3{%
  #2%
  \pgf@xa=-\pgf@x
  \origpgfpathellipse{#1}{\pgfqpoint{\pgf@xa}{0pt}}{#3}}
\makeatother

\tikzset{
  reversed ellipse/.style={
    ellipse,
    reverse the ellipse%
  },
  reverse the ellipse/.code={
    \let\pgfpathellipse=\revpgfpathellipse
  }
}
\begin{document}
\begin{tikzpicture}
\node[ellipse,
  draw,
  postaction={
    decorate,
    decoration={
      markings,
      mark=at position 1 with {
        \arrow[line width=5pt,blue]{>}
      }
    }
  }
] at (0,0) {hello world};

\node[reversed ellipse,
  draw,
  postaction={
    decorate,
    decoration={
      markings,
      mark=at position 1 with {
        \arrow[line width=5pt,blue]{>}
      }
    }
  }
] at (0,-2) {hello world};
\end{tikzpicture}

\end{document}

Here's the result:

rotated ellipse

(the arrow got clipped, but you can see where it lies)

[Tex/LaTex] How to define the default vertical distance between nodes

I don't really get the question so I hope this is what you wanted. If you include a full document (such that we copy paste and see the problem on our systems) things are much more easier.

Here, you can change the default setting within a scope but your block style had a node distance which was resetting every time it is issued. I've made it 2mm such that we can see the difference easier.

\documentclass[tikz]{standalone}
\usetikzlibrary{arrows,shapes.geometric,positioning}

\begin{document}
\begin{tikzpicture}[decision/.style={diamond, draw, text width=4.5em, text badly centered, node distance=3.5cm, inner sep=0pt},
                    block/.style   ={rectangle, draw, text width=6em, text centered, rounded corners, minimum height=4em, minimum height=2em},
                    cloud/.style   ={draw, ellipse, minimum height=2em},
                    line/.style    ={draw,-latex'},
                    node distance = 1cm, 
                    auto]
    \node [block] (1st) {1st};
    \node [block, right= of 1st]  (2nd1) {2nd1};
\begin{scope}[node distance=2mm and 10mm]%Here we change it for everything inside this scope
    \node [block, above= of 2nd1] (2nd2) {2nd2};
    \node [block, below= of 2nd1] (2nd3) {2nd3};
    \node [block, right= of 2nd1] (3rd1) {3rd1};
    \node [block, above= of 3rd1] (3rd2) {3rd2};
    \node [block, above= of 3rd2] (3rd3) {3rd3};
\end{scope}
    \node [block, below= of 3rd1] (3rd4) {3rd4};
    \node [block, below= of 3rd4] (3rd5) {3rd5};

    \path [line] (1st) -- (2nd1);
    \path [line] (2nd1) -- (2nd2);
    \path [line] (2nd1) -- (2nd3);
    \path [line] (2nd2) -- (3rd3);
    \path [line] (2nd1) -- (3rd1);
    \path [line] (1st) -- (2nd1);
\end{tikzpicture}
\end{document}

enter image description here

Best Answer

Related Solutions

[Tex/LaTex] Rotate a node but not its content: the case of the ellipse decoration

[Tex/LaTex] How to define the default vertical distance between nodes

Related Question