title: Plotly not displaying correctly in RStudio Viewer
body: <p>I am using the <code>plotly</code> package for the first time to generate 3D plots. Although I am following the tutorial, the plot points don't appear in the RStudio Viewer. Just an empty grid. <a href="https://i.stack.imgur.com/I5OCk.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/I5OCk.jpg" alt="enter image description here" /></a></p>
  <pre><code>library(plotly)
  packageVersion('plotly')
  #[1] ‘4.6.0’
  
  mtcars$am[which(mtcars$am == 0)] &lt;- 'Automatic'
  mtcars$am[which(mtcars$am == 1)] &lt;- 'Manual'
  mtcars$am &lt;- as.factor(mtcars$am)
  
  p &lt;- plot_ly(mtcars, x = ~wt, y = ~hp, z = ~qsec, color = ~am, colors = c('#BF382A', '#0C4B8E')) %&gt;%
    add_markers() %&gt;%
    layout(scene = list(xaxis = list(title = 'Weight'),
                        yaxis = list(title = 'Gross horsepower'),
                        zaxis = list(title = '1/4 mile time')))
  </code></pre>
  <p>However, when I open the plot in a web browser, the points show up fine.</p>
  <p>I see a similar question here: <a href="https://stackoverflow.com/questions/34214546/plotly-in-rstudio-viewer">Plotly in RStudio viewer</a></p>
  <p>But after updating to the latest version of RStudio the points still do not appear. I am using R version 3.3.3</p>