fix add-text behavior (#582)

* fix add-text behavior

* fix Result animation

* avoid double text for animation

* avoid double text for animation; fix test

Author: akaszynski

ansys/mapdl/reader/cyclic_reader.py

@@ -1595,9 +1595,12 @@ def animate_nodal_solution(
         movie_filename=None,
         **kwargs,
     ):
-        """Animate nodal solution.  Assumes nodal solution is a
-        displacement array from a modal solution.
+        """Animate nodal solution.
 
+        Assumes nodal solution is a displacement array from a modal solution.
+
+        Parameters
+        ----------
         rnum : int or list
             Cumulative result number with zero based indexing, or a
             list containing (step, substep) of the requested result.
@@ -1617,8 +1620,8 @@ def animate_nodal_solution(
             Shows the phase at each frame.
 
         add_text : bool, optional
-            Includes result information at the bottom left-hand corner
-            of the plot.
+            Includes result information at the top left-hand corner of the
+            plot. Set font size with the ``font_size`` parameter.
 
         interpolate_before_map : bool, optional
             Leaving this at default generally results in a better plot.
@@ -1629,9 +1632,27 @@ def animate_nodal_solution(
             A single loop of the mode will be recorded.
 
         kwargs : optional keyword arguments, optional
-            See help(pyvista.plot) for additional keyword arguments.
+            See :func:`pyvista.plot` for additional keyword arguments.
+
+        Examples
+        --------
+        Generate a movie of a mode shape while plotting off-screen.
+
+        >>> from ansys.mapdl.reader import read_binary
+        >>> rst = read_binary("academic_rotor.rst")
+        >>> rst.animate_nodal_displacement(
+        ...     (3, 2),
+        ...     displacement_factor=0.02,
+        ...     movie_filename="movie.mp4",
+        ...     off_screen=True
+        ... )
 
         """
+        # Avoid infinite while loop by ensure looping is disabled if off screen
+        # and writing a movie
+        if movie_filename and kwargs.get("off_screen", False):
+            loop = False
+
         if "nangles" in kwargs:  # pragma: no cover
             n_frames = kwargs.pop("nangles")
             warnings.warn(
@@ -1675,6 +1696,7 @@ def animate_nodal_solution(
             scalars = (complex_disp * complex_disp).sum(1) ** 0.5
 
         # initialize plotter
+        font_size = kwargs.pop("font_size", 16)
         text_color = kwargs.pop("text_color", None)
         cpos = kwargs.pop("cpos", None)
         off_screen = kwargs.pop("off_screen", None)
@@ -1697,9 +1719,8 @@ def animate_nodal_solution(
 
         # setup text
         if add_text:
-            text_actor = plotter.add_text(
-                " ", font_size=20, position=[0, 0], color=text_color
-            )
+            # results in a corner annotation actor
+            text_actor = plotter.add_text(" ", font_size=font_size, color=text_color)
 
         if cpos:
             plotter.camera_position = cpos
@@ -1740,8 +1761,9 @@ def q_callback():
                 plot_mesh.points[:] = orig_pt + complex_disp_adj
 
                 if add_text:
-                    text_actor.SetInput(
-                        "%s\nPhase %.1f Degrees" % (result_info, (angle * 180 / np.pi))
+                    text_actor.set_text(
+                        2,  # place in the upper left
+                        f"{result_info}\nPhase {np.rad2deg(angle):.1f} Degrees",
                     )
 
                 plotter.update(1, force_redraw=True)

ansys/mapdl/reader/rst.py

@@ -2979,7 +2979,9 @@ def _plot_point_scalars(
             Increases or decreases displacement by a factor.
 
         add_text : bool, optional
-            Adds information about the result when rnum is given.
+            Adds information about the result when rnum is given. Control the
+            font size with the ``font_size`` parameter and text color with
+            ``text_color``.
 
         overlay_wireframe : bool, optional
             Overlay a wireframe of the original undeformed mesh.
@@ -3090,7 +3092,7 @@ def _plot_point_scalars(
         # remove extra keyword args
         kwargs.pop("node_components", None)
         kwargs.pop("sel_type_all", None)
-
+        font_size = kwargs.pop("font_size", 16)
         if overlay_wireframe:
             plotter.add_mesh(self.grid, style="wireframe", color="w", opacity=0.5)
 
@@ -3117,10 +3119,11 @@ def _plot_point_scalars(
             else:
                 plotter.open_movie(movie_filename)
 
-        # add table
         if add_text and rnum is not None:
             result_text = self.text_result_table(rnum)
-            plotter.add_text(result_text, font_size=20, color=text_color)
+            if not animate:
+                # avoid adding twice
+                plotter.add_text(result_text, font_size=font_size, color=text_color)
 
         # camera position added in 0.32.0
         show_kwargs = {}
@@ -3164,6 +3167,13 @@ def exit_callback(plotter, RenderWindowInteractor, event):
                     lambda render, event: exit_callback(plotter, render, event),
                 )
 
+            # setup text
+            if add_text:
+                # results in a corner annotation actor
+                text_actor = plotter.add_text(
+                    " ", font_size=font_size, color=text_color
+                )
+
             first_loop = True
             cached_normals = [None for _ in range(n_frames)]
             while self._animating:
@@ -3184,8 +3194,10 @@ def exit_callback(plotter, RenderWindowInteractor, event):
                             copied_mesh.point_data["Normals"][:] = cached_normals[j]
 
                     if add_text:
-                        phase = angle * 180 / np.pi
-                        plotter.add_text(f"{result_text} \nPhase {phase} Degrees")
+                        text_actor.set_text(
+                            2,  # place in the upper left
+                            f"{result_text}\nPhase: {np.rad2deg(angle):.1f} Degrees",
+                        )
 
                     # at max supported framerate
                     plotter.update(1, force_redraw=True)
@@ -3311,6 +3323,7 @@ def _animate_point_scalars(
         # screenshot = kwargs.pop('screenshot', None)
         # interactive = kwargs.pop('interactive', True)
         text_color = kwargs.pop("text_color", None)
+        font_size = kwargs.pop("font_size", 16)
 
         kwargs.setdefault("smooth_shading", True)
         kwargs.setdefault("color", "w")
@@ -3360,7 +3373,9 @@ def _animate_point_scalars(
         if text is not None:
             if len(text) != len(scalars):
                 raise ValueError("Length of ``text`` must be the same as ``scalars``")
-            plotter.add_text(text[0], font_size=20, color=text_color)
+            text_actor = plotter.add_text(
+                text[0], font_size=font_size, color=text_color
+            )
 
         # orig_pts = copied_mesh.points.copy()
         plotter.show(
@@ -3391,7 +3406,7 @@ def q_callback():
                 copied_mesh.active_scalars[:] = data
 
                 if text is not None:
-                    plotter.add_text(text[i])
+                    text_actor.set_text(2, text[i])  # place in the upper left
 
                 # at max supported framerate
                 plotter.update(1, force_redraw=True)