diff --git a/app/core/gimpcontext.c b/app/core/gimpcontext.c
index 06b24c0483..5b2318a609 100644
--- a/app/core/gimpcontext.c
+++ b/app/core/gimpcontext.c
@@ -2491,7 +2491,6 @@ GimpDynamics *
 gimp_context_get_dynamics (GimpContext *context)
 {
   g_return_val_if_fail (GIMP_IS_CONTEXT (context), NULL);
-  g_return_val_if_fail (GIMP_IS_DYNAMICS (context->dynamics), NULL);
 
   return context->dynamics;
 }
@@ -2504,7 +2503,6 @@ gimp_context_set_dynamics (GimpContext           *context,
   g_return_if_fail (! dynamics || GIMP_IS_DYNAMICS (dynamics));
   context_find_defined (context, GIMP_CONTEXT_PROP_DYNAMICS);
 
-  printf("setting&OK\n");
   gimp_context_real_set_dynamics (context, dynamics);
 }
 
@@ -2565,7 +2563,6 @@ static void
 gimp_context_real_set_dynamics (GimpContext           *context,
                                 GimpDynamics          *dynamics)
 {
-  g_return_val_if_fail (GIMP_IS_DYNAMICS (dynamics), NULL);
 
   if (! standard_dynamics)
     {
diff --git a/app/core/gimpdynamics.c b/app/core/gimpdynamics.c
index c2637f3830..8d922e4188 100644
--- a/app/core/gimpdynamics.c
+++ b/app/core/gimpdynamics.c
@@ -844,7 +844,6 @@ gimp_dynamics_notify (GObject    *object,
 
   GimpDynamics *options = GIMP_DYNAMICS (object);
 
-
 }
 
 GimpData *
@@ -880,7 +879,7 @@ gimp_dynamics_get_standard (void)
 }
 
 gdouble
-gimp_dynamics_get_output_val (GimpDynamicsOutput *output, GimpCoords coords)
+gimp_dynamics_get_linear_output_val (GimpDynamicsOutput *output, GimpCoords coords)
 {
   gdouble total = 0.0;
   gdouble factors = 0.0;
@@ -898,10 +897,17 @@ gimp_dynamics_get_output_val (GimpDynamicsOutput *output, GimpCoords coords)
       total += (1.0 - coords.velocity);
       factors++;
     }
+
+  if (output->random)
+    {
+      total += g_random_double_range (0.0, 1.0);
+      factors++;
+    }
+
   if (factors > 0)
     result = total / factors;
 
-  //printf("Dynamics queried. Result: %f, vel %f, f: %f, t: %f \n", result, coords.velocity, factors, total);
+  printf("Dynamics queried. Result: %f, factors: %f, total: %f \n", result, factors, total);
   return result;
 }
 
diff --git a/app/core/gimpdynamics.h b/app/core/gimpdynamics.h
index 3b4901186e..523bfa3200 100644
--- a/app/core/gimpdynamics.h
+++ b/app/core/gimpdynamics.h
@@ -90,6 +90,6 @@ GimpData           * gimp_dynamics_new   (const gchar *name);
 
 GimpData           * gimp_dynamics_get_standard     (void);
 
-gdouble            gimp_dynamics_get_output_val (GimpDynamicsOutput *output, GimpCoords coords);
+gdouble            gimp_dynamics_get_linear_output_val (GimpDynamicsOutput *output, GimpCoords coords);
 
 #endif  /*  __GIMP_DYNAMICS_OPTIONS_H__  */
diff --git a/app/paint/gimpbrushcore.c b/app/paint/gimpbrushcore.c
index 58563960da..057409301e 100644
--- a/app/paint/gimpbrushcore.c
+++ b/app/paint/gimpbrushcore.c
@@ -403,11 +403,11 @@ gimp_brush_core_start (GimpPaintCore     *paint_core,
 
       if (core->dynamics)
         {
-          core->scale *= gimp_dynamics_get_output_val(core->dynamics->size_dynamics, *coords);
+          core->scale *= gimp_dynamics_get_linear_output_val(core->dynamics->size_dynamics, *coords);
 
-          core->angle += gimp_dynamics_get_output_val(core->dynamics->angle_dynamics, *coords);
+          core->angle += gimp_dynamics_get_linear_output_val(core->dynamics->angle_dynamics, *coords);
 
-          core->aspect_ratio *= gimp_dynamics_get_output_val(core->dynamics->aspect_ratio_dynamics, *coords);
+          core->aspect_ratio *= gimp_dynamics_get_linear_output_val(core->dynamics->aspect_ratio_dynamics, *coords);
         }
     }
 
@@ -756,11 +756,11 @@ gimp_brush_core_get_paint_area (GimpPaintCore    *paint_core,
 
       if (core->dynamics)
       {
-        core->scale *= gimp_dynamics_get_output_val(core->dynamics->size_dynamics, *coords);
+        core->scale *= gimp_dynamics_get_linear_output_val(core->dynamics->size_dynamics, *coords);
 
-        core->angle += gimp_dynamics_get_output_val(core->dynamics->angle_dynamics, *coords);
+        core->angle += gimp_dynamics_get_linear_output_val(core->dynamics->angle_dynamics, *coords);
 
-        core->aspect_ratio *= gimp_dynamics_get_output_val(core->dynamics->aspect_ratio_dynamics, *coords);
+        core->aspect_ratio *= gimp_dynamics_get_linear_output_val(core->dynamics->aspect_ratio_dynamics, *coords);
 
       }
     }
diff --git a/app/paint/gimppaintbrush.c b/app/paint/gimppaintbrush.c
index c23a6f7a0d..6c85253df4 100644
--- a/app/paint/gimppaintbrush.c
+++ b/app/paint/gimppaintbrush.c
@@ -131,7 +131,7 @@ _gimp_paintbrush_motion (GimpPaintCore    *paint_core,
 
   paint_appl_mode = paint_options->application_mode;
 
-  grad_point = gimp_dynamics_get_output_val(brush_core->dynamics->color_dynamics, *coords);
+  grad_point = gimp_dynamics_get_linear_output_val(brush_core->dynamics->color_dynamics, *coords);
 
   /* optionally take the color from the current gradient */
   if (gimp_paint_options_get_gradient_color (paint_options, image,
@@ -176,9 +176,9 @@ _gimp_paintbrush_motion (GimpPaintCore    *paint_core,
                     area->bytes);
     }
 
-  opacity *= gimp_dynamics_get_output_val(brush_core->dynamics->opacity_dynamics, *coords);
+  opacity *= gimp_dynamics_get_linear_output_val(brush_core->dynamics->opacity_dynamics, *coords);
 
-  hardness = gimp_dynamics_get_output_val(brush_core->dynamics->hardness_dynamics, *coords);
+  hardness = gimp_dynamics_get_linear_output_val(brush_core->dynamics->hardness_dynamics, *coords);
 
   /* finally, let the brush core paste the colored area on the canvas */
   gimp_brush_core_paste_canvas (brush_core, drawable,