diff --git a/config.cpp b/config.cpp
index f2673339..a2d4e882 100644
--- a/config.cpp
+++ b/config.cpp
@@ -1762,4 +1762,53 @@ int read_gamemode_args() {
 auto ah_config = addHook(hooks_args, 0, read_config_args) + addHook(hooks_args, 0, read_gamemode_args);
 #endif
 
+unordered_map<string, ld&> params = {
+  {"linewidth", vid.linewidth},
+  {"patternlinewidth", linepatterns::width},
+  {"scale", vid.scale},
+  {"xposition", vid.xposition},
+  {"yposition", vid.yposition},
+  {"projection", vid.alpha},
+  {"sspeed", vid.sspeed},
+  {"mspeed", vid.mspeed},
+  {"ballangle", vid.ballangle},
+  {"yshift", vid.yshift},
+  {"cameraangle", vid.camera_angle},
+  {"depth", geom3::depth},
+  {"camera", geom3::camera},
+  {"wall_height", geom3::wall_height},
+  {"highdetail", geom3::highdetail},
+  {"middetail", geom3::middetail},
+  {"rock_wall_ratio", geom3::rock_wall_ratio},
+  {"human_wall_ratio", geom3::human_wall_ratio},
+  {"lake_top", geom3::lake_top},
+  {"lake_bottom", geom3::lake_bottom},
+  {"rug_model_distance", rug::model_distance},
+  {"star", polygonal::STAR},
+  {"lvspeed", conformal::lvspeed},
+  {"rotation", conformal::rotation},
+  {"mori", conformal::model_orientation},
+  {"topz", conformal::top_z},
+  {"mtrans", conformal::model_transition},
+  {"hp", conformal::halfplane_scale},
+  {"back", backbrightness},
+  {"ipd", stereo::ipd},
+  {"lr", stereo::lr_eyewidth},
+  {"anaglyph", stereo::anaglyph_eyewidth},
+  {"fov", stereo::fov},
+  {"ets", vid.euclid_to_sphere},
+  {"stretch", vid.stretch},
+  {"twopoint", vid.twopoint_param},
+  {"bwidth", vid.binary_width},
+  {"aperiod", anims::period},
+  {"acycle", anims::cycle_length},
+  {"aparabolic", anims::parabolic_length},
+  {"arugangle", anims::rug_angle},
+  {"acradius", anims::circle_radius},
+  {"acspins", anims::circle_spins},
+  {"mobius", vid.skiprope},
+  {"a", anims::a},
+  {"b", anims::b},
+  };
+
 }
diff --git a/hyper.h b/hyper.h
index 3eb746c2..9f51a882 100644
--- a/hyper.h
+++ b/hyper.h
@@ -2061,6 +2061,7 @@ namespace anims {
   void animate_parameter(ld &x, string f, const reaction_t& r);
   void deanimate(ld &x);
   void get_parameter_animation(ld &x, string& f);
+  extern ld a, b;
   }
 
 namespace arg {
@@ -4353,5 +4354,7 @@ struct bandfixer {
 
 inline void delayed_geo_reset() { need_reset_geometry = true; }
 
+extern unordered_map<string, ld&> params;
+
 }
 
diff --git a/screenshot.cpp b/screenshot.cpp
index f1fb76d3..3b410435 100644
--- a/screenshot.cpp
+++ b/screenshot.cpp
@@ -579,6 +579,25 @@ void animator(string caption, ld& param, char key) {
     });
   }
 
+ld a, b;
+
+void list_animated_parameters() {
+  dialog::addHelp(XLAT(
+    "Most parameters can be animated simply by using '..' in their editing dialog. "
+    "For example, the value of a parameter set to 0..1 will grow linearly from 0 to 1. "
+    "You can also use functions (e.g. cos(0..2*pi)) and refer to other parameters; "
+    "parameters 'a' and 'b' exist for this purpose. "
+    "See the list below for parameters which are currently animated (or changed)."));
+  dialog::addBreak(50);
+  for(auto& ap: aps) {
+    string what = "?";
+    for(auto& p: params) if(&p.second == ap.value) what = p.first;
+    dialog::addInfo(what + " = " + ap.formula);
+    }
+  dialog::addBreak(50);
+  dialog::addHelp(parser_help());
+  }
+
 ld animation_period;
 
 void show() {
@@ -727,10 +746,17 @@ void show() {
   else if(among(pmodel, mdHyperboloid, mdHemisphere, mdBall))
     animator(XLAT("3D rotation"), ballangle_rotation, 'r');
   
-  /*
-  animator(XLAT("animate parameter change"), anim_param, 'P');
-  dialog::addSelItem(XLAT("choose parameters to animate"), its(paramstate), 'C');
-  dialog::add_action(next_paramstate); */
+  dialog::addSelItem(XLAT("animate parameters"), fts(a), 'a');
+  dialog::add_action([] () {
+    dialog::editNumber(a, -100, 100, 1, 0, XLAT("animate parameters"), "");
+    dialog::extra_options = list_animated_parameters;
+    });
+
+  dialog::addSelItem(XLAT("animate parameters"), fts(b), 'b');
+  dialog::add_action([] () {
+    dialog::editNumber(b, -100, 100, 1, 0, XLAT("animate parameters"), "");
+    dialog::extra_options = list_animated_parameters;
+    });
 
   dialog::addBoolItem(XLAT("history mode"), (conformal::on || conformal::includeHistory), 'h');
   dialog::add_action([] () { pushScreen(conformal::history_menu); });
diff --git a/util.cpp b/util.cpp
index 876d143a..c89ae0fb 100644
--- a/util.cpp
+++ b/util.cpp
@@ -202,9 +202,10 @@ cld exp_parser::parse(int prio) {
     else if(number == "p" || number == "pi") res = M_PI;
     else if(number == "" && next() == '-') { at++; res = -parse(prio); }
     else if(number == "") at = -1;
-    else if(extra_params.count(number)) res = extra_params[number];
     else if(number == "s") res = ticks / 1000.;
     else if(number == "ms") res = ticks;
+    else if(extra_params.count(number)) res = extra_params[number];
+    else if(params.count(number)) res = params.at(number);
     else if(number[0] >= 'a' && number[0] <= 'z') at = -1;
     else { std::stringstream ss; res = 0; ss << number; ss >> res; }
     }