Navigating and Embedding the Interactive Plots
This function opens an interactive Open GL window rendered by rgl.
If save==TRUE and close_after_save==TRUE, the window will be
closed after the function call. Otherwise, it is kept open and the following
information applies:
To navigate the plot, left click and drag the cursor to rotate. Use the
scroll wheel or right click and drag to zoom. Press the scroll wheel and drag
to change the field-of-view. Execute snapshot to save the
current window as a .png file. Execute rgl.close to close
the window. rgl.viewpoint can be used for programmatic
navigation.
The Open GL window can be embedded as an htmlwidget in an R Markdown document
using one of two methods. The first is executing rglwidget
in the chunk where the plot is made. This first method should work within
both the RStudio IDE and a knitted .html file. The second method is
executing setupKnitr at the start of the document and
then using the chunk option webgl=TRUE in the chunk where the plot is
made. The second method is specifically for knitted .html files. Although
the first method is the newest approach and is recommended by others, we
used the second method in the ciftiTools vignette because the first
is not compatible with htmlpreview. For both methods, the window still
needs to be open to render the widget. Also for both methods, you will
probably need to tweak the image dimensions e.g.
fig.width=8, fig.height=5 in the chunk options, because it uses the
defaults from RMarkdown/Knitr instead of what makes sense based on the
dimensions of the Open GL window.
For view_xifti_surface, if length(idx) > 1, this function will
automaticaly return an htmlwidget using the first method, but with a
playwidget wrapper to add a slider to control which
column index is being displayed. All the meshes will be rendered on top of
one another in the Open GL window, so only the widget will be useful for
viewing the data interactively. Since it uses the first method, it will not
be visible with htmlpreview. No additional call to
rglwidget is necessary, but rgl.close
must be called in a following chunk to close the Open GL window.