Improved action mechanics

So, I’ve made some improvements in the action-interaction system. It has been a long-needed update. In different games player is able to perform different actions, not only just run, jump and shoot. Well, honestly, a major part the gameplay nowadays is built around actions and interactions, so inadequate and ineffective solutions are unacceptable. This leads us to a completely new domain of problems: we need a separate mechanism for performing character’s actions. The concept is simple: there are some actions, each can be performed by the character. An action has certain properties, like it’s relationship with animation — an action may or may not have an animation, and it’s relationship with character state and other actions — an action may or may not have effects on the game pawn (except the animations effect). Thus, we come to a fairly easy solution — the LBBasicCharacaterController, which is capable of performing actions, which means the ability to play animations and change pawn’s states (virtually, of course). Basically, we’ll be working only with current character’s logic, leaving all underlying activity to the basic character controller. So, we’re interested in only in these methods:

function HandleActionStart(int startedaction)
{ }
function HandleActionStop(int stoppedaction)
{ }
function HandleAnimNotify(int actioncode, int actiondata, 
ActionNotifyTypes notifytype)
{ }

Which do handle action start, action end and animation notifies, which may or may not trigger during the action animation. If we don’t need any character-specific logic or we just want a Garry’s Mod-styled animation player, we can just use the editor. For the designer it’s really simple — all what’s required is to fill out the Character Action List in the editor, which contains all the necessary data.

char_interact_params_1_1.PNG

For example, here I’ve made four basic actions: touch, pick up, put down, carry, three last interactions I’ve been describing earlier, the touch action and the appropriate interaction I’ll describe later. Also I’ve made some auxiliary actions, which really don’t have any effect in the game, except they do play animation. All options of this actions are shown below, for example, them options of the touch action mean that this action is controlled by the certain animation: the action starts with the animation and ends with this animation, also it may have activation restrictions and switch links. What is activation restriction? It’s simple — the action cannot be performed from any actions (state-actions), except these. And the switch link is a type of  a bridge between the actions — upon its finish, the action can be automatically switched to another one. Well, I’ve made some comments (been trying my best) in sources on GitHub.

char_interact_params_1_2

Next thing, what is required — the proper animation, set up and linked to the LBBlendByAction animnode, which blends all animations. There’s also a default node, which is used to blend out, when the default action is active.

animtree_nodes_1_1.PNG

Thus, all, what’s required now is to call a needed action by the SetParamInt() function with param name ‘BeginAction‘ and param value containing the action code. Also, this can be performed from any sub-system, but I’ve chosen Kismet and its keyboard events.

kismet_nodes_4

Well, let’s test this functionality. I’ve made some random (though interdependent) animation sequences (though craggy) for the character, then plugged them into the new action system. There’s a state-action, which defines character’s state — the ‘Sit_Tie_Idle‘ action. There are also two gateway-actions — the ‘Sit_Tie_In‘ as an entrance into this state and the ‘Sit_Tie_Out‘ as an exit. And there are two actions, performed exclusively from the ‘Sit_Tie_Idle‘ state — the ‘Sit_Tie_Gym_1‘ and the ‘Sit_Tie_Gym_2‘.

Now we can make our character do different things. For example, we can watch our strange character doing its strange exercises (some kind of gym, maybe?). However, everything happens in the right order, for example, it can’t just start walking or jumping from a stretched pose, it has to stand up first.

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Improved action mechanics

Some test run on a new level

Just made a test run on a level I’ve made recently. Playing with ground-walking bipedal character (xw_char), which is capable of walk, run and jump. Also, there’s a good, smooth camera plugged in, which can be attached to almost everything.

Yes, now we’re able to jump. I’ve decided to make ground characters able to jump. Why not, it’s qute fair in comparison with other characters, which can fly or event teleport (but can’t walk, lol). However jump system needs some fix.

There’s also another interactive actor – the way-pointer (mg_char). Most of the time the player just follows this actor. When the player is too far away it stops moving, and when the player is close – it speeds up (such a hackneyed idea).

Well, let’s look, how it all works all together. However, it turned out to be quite hard to use keyboard instead ot the joystick (okay, gamepad).

Some test run on a new level

Movement mechanics

Almost the first time doing serious bipedal movement mechanics and animation. Let’s make a first step into the complex character animation (or not). Anyway, here’s the workflow. Honestly, once I’ve been involved in such an affair… And things did not go very well, but that was then. Anyways, now is the first real attempt to create an acceptable bipedal character movement animation and mechanics. First, I’ve made a complete redesign of an old version of movement mechanic, which was a special pawn and was very hard to use. Well, now it looks shiny and new, now this code goes to a new separate mechanism — LBCharacterWalkMovementMechanism, which is now based on LBCharacterMovementMechanism (empty at the moment, lol) and conains all the code, needed for performing pawn movement and blending the animation. It also has all parameters, which are used to regulate pawn’s speed and acceleration.

walk_movement_mechanism

It has the forward speed parameter and a forward speed coefficient to handle forward speed, same to the sidestep (strafe?) speed. Also it has accel rate, which is used to speed the pawn up, when it wants to run. Another important thing here is the angular speed, which is represented by angular speed parameter and an angular speed coefficient, which are used to handle pawn’s rotation. Also it has move direction, which is used to point the desired movement direction. It’s worth noting, that pawn rotation is quite an interesting task itself (later on this). Second, I’ve made several frames of animation for the character, the walker (xw_char). It wasn’t easy, because someone’s left in it’s feet only one bone. Maybe it was even me. Anyways, there are two fairly appropriate animations sequences:

Simple walk animation:

xenowalker_walk_gifxenowalker_walk_gif_side

Simple run animation:

xenowalker_run_gifxenowalker_run_gif_side

Other intermediate and supportive animations are quite crappy to be shown here. It should be noted that I used the walk and run cycle tutorials by Richard Williams as a reference (found all over the internet) for my walk and run animations. As a result, we’ve got the following animtree:

Where BlendByAngSpeed node does blending between middle, left and right turn sequences and BlendByFwdSpeed node does blending between walk and run sequences. Also, while blending between walk and run is quite a simple task, but blending between rotations seems to be more complex. Using unique animation sequences turned out be the best way to solve this problem, others, like using direct bone rotations may cause weired effects in my animtree during blending between states, for example. Finally, we’ve got the result, let’s see how does it look all together:

Walk and run animations in game:

Turn and turn in place animations in game:

However, complex tests reveal some flaws, like minor body jerking and leg rattling, also there’s still no jump and sidestep implementation. And ofcourse, the camera is terrible, but controlling with joystick (gamepad) partially solves the problem. Nevertheless, in general it looks not too bad.

Movement mechanics

Inventory mechanics

Well, it’s up. Time to test some inventory mechanics. Start with an LBPawn (xc_char), which has been already set up. The character itself doesn’t seem to have any hands, so it uses its mouth to pick up objects. It’s quite a complex task to make a correct body and neck bend animation (it’s still not correct). Well, handling hand animations is even hareder. But in future I’ll think about it. Maybe.

To handle all interactions the pawn interactable controller is used (LBPawnInteractableController), which is a part of mechanism system. All actions are set in the editor by setting names of corresponding animations.

pawn_action_list

All animation names are linked to animtree nodes, and the slider node (blendbyaction) is controlled from the code.

animtree_example

For example, the slider for drop down action is set to child number five on activation of interaction number six (full code).

else if (value == 6)
 {
  //activate interaction: Drop down
  if (curaction != 0)
   return; 
  if (!CheckInteractioConditions(3))
  {
   LogError("proc: ActivateInteraction() return: [CheckInteractioConditions(3)] returned false!"); 
   return; 
  }
  blendbyaction.SetActiveChild(6, 0.5);
  actionseqs[5].SetPosition(0.0, false);
  actionseqs[5].PlayAnim(false, 0.8, 0.0); 
 }

Yes, slider control is hard-coded in the mechanism, it’s a shame, I know. Then, the animation is played. It fires animation notifies, which are set in the begining, the middle, where the action is performed and in the very end. Each one of them calls its own part of code (full code).

else if (notifynode.NodeName == 'Interaction_DropDown')
 {
  if (notifytype == AnimNotifyTypes_ActionStart)
  {
  curaction=6;
  }
  else if (notifytype == AnimNotifyTypes_PerformAction)
  {
   PerformInteraction(3);
  }
  else if (notifytype == AnimNotifyTypes_ActionEnd)
  {
   blendbyaction.SetActiveChild(0, 0.5);
   curaction=0;
  }
 }

The PerformInteraction function performes the real work: sets all properties of invoked objects. In this case it just tells the held object’s mechanism that it’s free to go.

All inventory objects are equipped with LBAttachMechanism.( I don’t use the default attach system, because it’s a total hemorrhoid). And the pawn has its counterpart – the LBInventoryPawnMechanism, which does all the work.

inv_mech.png

It has a modifiable parameter – a socket, where all inventory is attached (in our case – a mouth). When needed, the parameter of this mechanism (InventoryMechanism) is set to certain actor. After several checks it adds this actor to inventory or doesn’t add this actor because it’s impossible. It could be implemented with one interaction from pawn controller mechanism.

SetTargetParam(parent, InventoryMechanism, 'AddObject', otheractor);

The other actor is selected from all actors in specified area in LBAreaCheckingMechanism based on the distance from the center of this area. It’s still not the best solution, because each time it uses an iterator, wich iterates through many objects in the level. I’m not using the default collision-overlapping system, because it’s a total hemorrhoid and moreover it’s a slow solution too.

Well, this was a first step towards a complex interaction system. It’s interesting, because many modern games do have quite a simple interaction systems. Even RPG games are tend to have more and more plain character-static world interaction system, but I think you can prove me wrong. Well, the result is shown below – the character is now able to pick up and put down any objects in the level.

 

Inventory mechanics