The collision layer system in ACTION GAME MAKER utilizes Godot’s system as-is.
By using it effectively, various configurations become possible.
Where to Configure Collisions
Wall Collision
-
GameObject: CollisionObject2D > Collision
-
Tile: TileMapLayer > Tile Settings (TileSet) > Physics Layers
Attack Collision
- AttackArea2D: CollisionObject2D > Collision
Hit Collision
- HitArea2D: CollisionObject2D > Collision
Collision Layer and Collision Mask
The Collision Layer defines which layer an object or tile belongs to.
The Collision Mask defines which layers an object or tile wants to collide with.
Organizing Collision Layer Names
You can assign names to collision layers via Project Settings > General > Layer Names > 2D Physics.
After setting, you can hover your cursor over the layer number to view its name.
Order of Evaluation: Groups and Attributes
- Collision Processing (Collision Layer / Collision Mask)
- Group / Attribute Processing
Evaluation occurs in this order.
Therefore, group/attribute processing does not occur between objects or tiles that do not collide.
Objects That Are Not Pushed
Since Collision Mask is one-way:
If Object A belongs to Layer 1 with a mask of only 1,
and Object B belongs to Layer 2 with a mask of 1 and 2,
Object A cannot detect contact with Object B, but Object B can detect contact with Object A.
In this case, Object A can push Object B, but Object B cannot push Object A.
This is due to a slightly complex concept:
Object A does not recognize a collision with Object B… however, since Object A is actually moving, Object B gets pushed as a result.
On the other hand, Object B recognizes the collision with Object A and attempts to push Object A… but since Object A does not recognize Object B, it does not move even by 1 pixel no matter how hard it is pushed.
Rideable Moving Platforms
By leveraging the above characteristic, if you set the mask of a rideable platform to nothing, you can create an invincible platform that does not shift regardless of what it collides with.