wxGUI/animation: add note about comp region

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@57871 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/animation/g.gui.animation.html

@@ -38,6 +38,11 @@ To display 3D view animation follow these steps:
 <br>
 </center>
 
+<h2>NOTE</h2>
+The Animation Tool follows the computational region settings,
+so please be sure your computational region is set to the geographic extent of maps you are animating.
+You can change the computational region (using <a href="g.region.html">g.region</a>)
+and then reload the maps to update the animation.
 
 <h2>TODO</h2>
 <ul>