Community Challenge #5: Break It! ⛓️‍💥

[Ivan]

Wow! Did your kids play it? I’m amazed! Thank you! Do you think if I put in more time and polish this could be accepted by Poki?

[kuyimobile]

Break It: Holey Moly

Made this small game when I was trying to learn Defold’s joints and collision shapes. It’s reminiscent of those funny Japanese hole-in-the-wall TV variety games. The goal is to rearrange the stick figure’s limbs to match the incoming hole shape by clicking and dragging the designated touch points.

Happy playing!

Game: Holey Moly by Kuyi Mobile

Github: GitHub - kuyimobile/Defold-Physics-Challenge: Defold Challenge #5 (Physics) · GitHub

[Pawel]

@Ivan

Wow! Did your kids play it? I’m amazed!

Always! They’re the best playtesters
And believe me, amount of fun they have is astonishing, they’re laughing all the time

[britzl]

@kuyimobile

Happy playing!

The game area is cropped for me:

[Mathias]

Me too on mobile

[kuyimobile]

Oops, sorry! @britzl @Mathias Can you please try again?

[kuyimobile]

So cool to see your kids playing the games!!

[JuLongZhiLu]

very insteresting ! I love to play it.

[Mathias]

Thanks it works fine now! Really nice game, I’ll check the code never used joints before

[jeanstkng]

Tentacle Thing

Hi! tried to do a Carrion-like project, I always wondered how it was done with all the tentacles and particles going through walls. I am pretty sure that it was built using a custom engine so they might have control of every pixel and that’s why even sections of the tentacles are able to collide with walls, tried a lot of ways, static tentacles, tentacle composed by multiple game objects doing some kind of ropes with fixed joints (this crashed many times so I just dropped it). Lastly I just asked an AI if there was a different way and that’s how I ended up with the mesh generated tentacles.

Repo: GitHub - jeanstkng/def-carrion-physics: A Defold Project where I try to mimic Carrion Game Physics with tentacle movement. · GitHub

Game: Tentacle Thing by jeanstkng

[Mathias]

Wow I really love it! Have a “Life” SF movie feel and the bleeding effect is really cool! Need to see the code, is it a shader effect or tile(map) changing? (EDIT: OK I just need to read the readme )

This creature could be a freaking enemy in an action game if you change the sphere to a space-octopus head

I wanted to make a game where the female character use her hair to grab things and hang on the ceil, this could be a good starting point!

[Sam]

I pushed a small update to the “my wagon thing”. Now there is turbo with W and you eventualy can hit the finish. My best score is 10.923 10.859 sec

[Pawel]

Thank you very much for all your submissions!

This time the competition was though and it was very hard for us to decide on the winners (1 vote decided in each category!), so congratulations!

• Best Technical: Tentacle Thing by @jeanstkng

• Best Visual: Wooden Wagon by @Sam

• Best First-time: Flip-Flop Football by @Ivan

Each of you will receive a 25 EUR Steam gift card!
I will contact you via DM here, so please answer

[Sam]

Thank you so much for the award!

I had a blast putting this together.

[Pawel]

When should the next Community Challenge be?

• April
• May
• June
• July
• Later

[Pawel]

Alright, so expect the next challenge pretty soon!

[Mathias]

Hi everybody!

I know this challenge is over since a long time, but I wanted to share the thing that I started with this challenge and that is playable now. I have completely give up the idea to respect any deadline in this matter, but I am still doing it at my own pace! I love theses challenges.

So here is a new version of my Tiny Games!

TinyGames 1.1.0

I will one day make an entry in the dev diaries topics, but when I will be ready.
TinyGames is a mean for me to learn Defold and be a bit more productive…because at the beginning I was creating a new project each time I would try something, but lose much time starting again and again. I couldn’t build up on what I’ve coded before..
So I build this project as a games portal, I have a bootstrap collection and some common libs that I share between games and augment as I learn Defold, then I have a dedicated folder for each games where I can try and learn specific topics in the context of a small game (this would be a good case for LiveUpdate… but in a future version!)

For now I made

• Baveur Vert : a space shooter with a green slobber ghost fighting sushi and food!
  • my first game. I learned inputs mapping, enemy spawning, first GUI hud, defold-events, virtual pad on mobile, gamepad on anbernic console with android version
• Mochi Fight! (comming soon!) : this will be a fighting game of japanese food!
  • I am still working on it, I want to implement a combo system and multiplayer game
  • but it seems it is a harder thing to do that I thought!

But today I present to you my new tiny game, Blob Planet!

I started it with this challenge, this is my first game using physics. First time also using runtime mesh generation and shaders.
So the concept is that you play a space Blob exploring the universe and just eating stuffs to expand and expand and expand! But beware of physical forces that will rip you apart and many dangers!

• Move with arrows (it creates a force towards arrow direction)
• or on mobile just touch the direction you want to go (it create a force towards the touch)
• if you are lost, double-hit rapidly backspace / back on mobile to go to title screen.

This is more a proof of concept than a game.

For now I have:

• Mr. Blob, which is a collection of many objects:
  • a core objects, the center, with a dynamic collisionobject
  • a factory that produces externals nodes around my core with dynamic collisionobjects too
    • every nodes are joint to the core with a physics joint
    • every nodes are joint to their neighbour with a physics joint
  • so the structural integrity depends on theses joints
  • the number of nodes and the radius of joints and the properties of the joints (frequency) are configurable with script properties
  • then over this structure, I generate at runtime a mesh with a vertex on each collision object, it is a fan triangulation
  • so I move objects in fixed_update(), and update mesh vertices/material variables in update()
  • the mesh use a material with a fixed noisy texture, but the texture is used twice with moving uv at different speeds, so it’s kind of organic. I also use 2 tints for light and dark green color, and another glow color (which handles time too) for the rim effect. This is the shader:

#version 140

in mediump vec2 var_texcoord0;
uniform mediump sampler2D tex0;
// uniform 
uniform fs_uniforms
{
	mediump vec4 tint;
	mediump vec4 tint2;
	mediump vec4 glow_color; // glow_color.w = time
};
out vec4 out_fragColor;

void main() {
	// Pre-multiply alpha since all runtime textures already are
	mediump vec4 tint_pm = vec4(tint.xyz * tint.w, tint.w);
	mediump vec4 tint2_pm = vec4(tint2.xyz * tint2.w, tint2.w);
	// 1. Calcul de la distance par rapport au centre (0.5, 0.5)
	// On suppose que  UVs sont bien mappés de 0 à 1 sur le cercle
	vec2 uv = var_texcoord0 - vec2(0.5);
	float dist = length(uv) * 2.0; // 0 au centre, 1 au bord

	// --- texture noise --------------
	float time = glow_color.w;
	// 1. On fait défiler deux couches de bruit à des vitesses différentes
	vec2 uv1 = var_texcoord0 + vec2(time * 0.05, time * 0.03);
	vec2 uv2 = var_texcoord0 - vec2(time * 0.02, time * 0.04);
	float noise1 = texture(tex0, uv1).r;
	float noise2 = texture(tex0, uv2).r;
	// 2. On mélange les deux pour un effet de "liquide" complexe
	float final_noise = (noise1 + noise2) * 0.5;
	dist += (final_noise - 0.5) *0.2; 
	// -------------------------------------
	
	// 2. Création de l'effet "Rim Light" 
	// Plus on est proche du bord (dist = 1), plus c'est brillant
	float rim = pow(dist, 5.0); 

	// 3. Simulation de translucidité
	// On veut que le centre soit un peu plus sombre ou transparent
	float alpha = smoothstep(1.0, 0.0, dist * dist * 0.2); 

	// 4. Mélange final
	vec3 final_color = mix(tint_pm.rgb, tint2_pm.rgb, final_noise); // mix tint and tint2
	final_color = mix(final_color, glow_color.rgb, rim ); // apply rim light effect

	// On multiplie par l'alpha du tint pour le contrôle global
	out_fragColor = vec4(final_color, alpha * tint_pm.a);
}

Now, this is a physics simulations, which mean FORCES!

I have implemented gravity forces, which you see in red because it is a debug build, but I will implement Coulomb (static electric charges) and Lorentz (moving electric charges in a magnetic fields) and any other things for fun gameplay (like vortex stuff!)

I’ve build a physics_manager and a physics_registry lua module.

• physics_registry role is to register physical objects of two kinds:

  • mobile objects that should undergo forces. here Mr Blob
  • “force-zones” that are game objects that produces forces. here the planets.
    • A force-zone defines the function to compute the force for some “physical points”. here gravity.
      • a physical point is an object with at least a position, a mass and a velocity, but also an electric charge or other physical properties.
    • A force-zone must have a trigger collision object that defines the activation of force calculation when mobile objects enter in the zone. I use simple shape, but we can have complicated force-zone shapes by accounting for geometry in the force calculation (like a SDF function in shaders)

• physics_manager role is to handle all global physics, so it defines a physics_world_listener which

  • activate/deactivate registered force-zones when a registered mobile objects enter in the zone (trigger event). So then the mobile object know which zone act upon it.
  • it can also repost physics events as standard on_message() messages to objects that are registered as listeners. When you use a global listener Defold stop forwarding messages automatically, but I still want some decentralised logic to be in game objects scripts. But the script must explicitly register in physics_registry as a listener.
  • in the fixed_update(), loop over all registered mobile objects and compute the forces to apply because of the force zones registered to this object
  • draw debug info for physics

Here each planet has configurable mass for gravity, mass for collisionobject, radius of planet, radius of trigger zone… so you can have a small planet with big gravity mass but a small bullet2d mass!

this is the physics_manager world_listener:

--- Listener for physics events
--- It reposts message to objects that have registry.register_listener(id)
--- It handle auto-registration of force zones triggers to mobile objects (if zone is in registry.register_zone(id) and mobile is in registre.register_mobile(id)
function M.physics_world_listener(self, events)
  for _, event in ipairs(events) do
    if event.type == M.RAY_CAST_RESPONSE then
      -- Handle raycast hit data
      --  pprint(event)
    elseif event.type == M.RAY_CAST_MISSED then
      -- Handle raycast miss data
      -- pprint(event)
    else
      local listener = registry.get_listener(event.a.id)
      local other_listener = registry.get_listener(event.b.id)
      if event.type == M.CONTACT_POINT_EVENT then
        -- Handle detailed contact point data
     --   pprint(event)
        if listener then
          M.repost_contact_point_response(event, false)
        end
        if other_listener then
          M.repost_contact_point_response(event, true)
        end
      elseif event.type == M.COLLISION_EVENT then
        -- Handle general collision data
     --   pprint(event)
        if listener then
          M.repost_collision_response(event, false)
        end
        if other_listener then
          M.repost_collision_response(event, true)
        end
      elseif event.type == M.TRIGGER_EVENT then
        -- Handle trigger interaction data
      --  pprint(event)
        -- mobile and zone auto-registration
        -- mobile zone détection
        M.handle_zone_triggers_registration(event.a.id, event.b.id, event.enter)
        if listener then
          M.repost_trigger_response(event, false)
        end
        if other_listener then
          M.repost_trigger_response(event, true)
        end
      end
    end
  end
end

And the fixed_update() loop:

function M.fixed_update(self, dt)
  for mobile_id, mobile in pairs(registry.mobiles) do
    if mobile then
      local force_points = mobile.fn_get_points()
      local total_forces = {}
      for i = 1, #force_points do
        total_forces[i] = vmath.vector3()
      end
      local has_force = false
      -- On itère sur toutes les zones qui influencent cet objet précis
      for zone_id, zone in pairs(mobile.active_zones) do
        if zone then
          local forces = zone.fn_compute_force(force_points)
          for i = 1, #force_points do
            total_forces[i] = total_forces[i] + forces[i]
            if vmath.length_sqr(total_forces[i]) > 0 then has_force = true end
          end
        end
      end

      -- Une seule application de force par objets mobiles, avec tous les points internes
      if has_force then
        mobile.fn_apply_forces(force_points, total_forces)
      end
    end
  end
end

When I will be more advanced in this code, I will shared this physics_manager module as it could be easily used for other games I think. Or just as an example.

Next steps:

• dissociate mesh points from collision objects of Mr. Blob: I want more vertices on the mesh to smooth it, they will be influences by the collision objects, but not exactly the same. I want to add animation to them too.
• add Blob eating stuff game mechanic: you eat, Blob grows.. and grows… and duplicate? add cores? create a nest? change blob physical properties? electric-blob? magnetic-blob? glueing blob? frozen, rock blob? Eat bad blob and gain their powers!
• many other types of force-zones and other mobile objects (bad blobs, floating stuffs, asteroids stars etc.)
• add a “landing” mechanics on planets so that it becomes more of a plateformer while on ground (ok this gonna be Blob Galaxy soon )
• add a minimap to not get lost in the universe!
• what else?

Well this was a longer post I thought I will do! Maybe it counts as a dev diary ^^
I hope you’ll like Mr. Blob and you could give some feedback about this little game.

As a final note, I want to say that I found Defold to be a truly great engine! I did all this with I found a lot less code I would expect. You have to think about organisation of things a bit first, and think “à la Defold”, but then the engine let you do everything you want in a graceful way. Thanks to all the team working on this thing.

[Pawel]

Blob Planet is awesome! So nice you finished it!