From e6fb8b69c85894994d649b4c7c59a6a1fa606c34 Mon Sep 17 00:00:00 2001 From: David Luevano Alvarado Date: Tue, 29 Aug 2023 04:17:09 -0600 Subject: add godot layer notes --- live/blog/g/flappybird_godot_devlog_2.html | 10 +- live/blog/g/godot_layers_and_masks_notes.html | 164 ++++++++++++++++++++++++++ live/blog/index.html | 1 + live/blog/rss.xml | 26 +++- live/blog/sitemap.xml | 8 +- live/blog/tag/@english.html | 1 + live/blog/tag/@gamedev.html | 1 + live/blog/tag/@gdscript.html | 1 + live/blog/tag/@godot.html | 1 + 9 files changed, 209 insertions(+), 4 deletions(-) create mode 100644 live/blog/g/godot_layers_and_masks_notes.html (limited to 'live/blog') diff --git a/live/blog/g/flappybird_godot_devlog_2.html b/live/blog/g/flappybird_godot_devlog_2.html index b7a5047..d4f764b 100644 --- a/live/blog/g/flappybird_godot_devlog_2.html +++ b/live/blog/g/flappybird_godot_devlog_2.html @@ -116,7 +116,7 @@

Porting to Godot 4

-

Disclaimer: I started the port back in Godot 4.0 something and left the project for a while, then opened the project again in Godot 4.1, and it didn’t ask to convert anything so probably nowadays the conversion is better.

+

Disclaimer: I started the port back in Godot 4.0 something and left the project for a while, then opened the project again in Godot 4.1, and it didn’t ask to convert anything so probably nowadays the conversion is better. Godot’s documentation is pretty useful, I looked at the GDScript reference and GDScript exports and that helped a lot.

General changes

These include the first changes for fixing some of the conflicting code to at least make it run (no gameplay) as well as project settings adjustments.

+ + + + Next + + @@ -299,7 +305,7 @@ AudioServer.set_bus_mute(_bus, true) # false to unmute

By David Luévano

Created: Sun, Aug 27, 2023 @ 23:28 UTC

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Modified: Mon, Aug 28, 2023 @ 00:37 UTC

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Modified: Tue, Aug 29, 2023 @ 10:14 UTC

Tags: english, gamedev, gdscript, godot

diff --git a/live/blog/g/godot_layers_and_masks_notes.html b/live/blog/g/godot_layers_and_masks_notes.html new file mode 100644 index 0000000..f13805e --- /dev/null +++ b/live/blog/g/godot_layers_and_masks_notes.html @@ -0,0 +1,164 @@ + + + + + + +Godot layers and masks notes -- Luévano's Blog + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
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Godot layers and masks notes

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The first time I learned about Godot’s collision layers and masks (will refer to them just as layers) I thought I understood them only to find out that they’re a bit confusing when trying to figure out interactions between objects that are supposed to detect each other. On my last entry where I ported the FlappyBird clone to Godot 4.1 I stumbled upon an issue with the bird not colliding properly with the pipes and the ceiling detector not… well, detecting.

+

At the end of the day the issue wasn’t that the layers weren’t properly setup but rather that the API to change the state of the collision layers changed between Godot 3 and Godot 4: when calling set_collision_layer_value (or .._mask) instead of specifying the bit which starts at 0, the layer_number is required that happens to start at 1. This was a headache for like an hour and made me realise that I didn’t understand layers that well or else I would’ve picked the error almost instantly.

+

While researching I found two really good short explainations that helped me grasp the concepts better in the same post, the first a bit technical (by Bojidar Marinov):

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  • If enemy’s mask and object’s mask are set to 0 (i.e. no layers), they will still collide with the player, because the player’s mask still includes their respective layers.
    • +
  • Overall, if the objects are A and B, the check for collision is A.mask & B.layers || B.mask & A.layers, where & is bitwise-and, and || is the or operator. I.e. it takes the layers that correspond to the other object’s mask, and checks if any of them is on in both places. It will then proceed to check it the other way around, and if any of the two tests passes, it would report the collision.
    • +
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And the second, shorter and less technical but still powerful (in the same post linking back to Godot 3.0: Using KinematicBody2D):

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    +
  • collision_layer describes the layers that the object appears in. By default, all bodies are on layer 1.
    • +
  • collision_mask describes what layers the body will scan for collisions. If an object isn’t in one of the mask layers, the body will ignore it. By default, all bodies scan layer 1.
    • +
+

While the complete answer is the first, as that is how layers work, the second can be used like a rule: 1) the layer is where the object lives, while 2) the mask is what the object will detect.

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By David Luévano

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Created: Tue, Aug 29, 2023 @ 10:10 UTC

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+

Tags: +english, gamedev, gdscript, godot

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+ +
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+ +
+ + + Contact + + + + + Donate + + + + + RSS + + +
+ + + Created with pyssg + + +
+ + Copyright 2023 David Luévano Alvarado + + +
+ + \ No newline at end of file diff --git a/live/blog/index.html b/live/blog/index.html index 62e68e7..6b32ad9 100644 --- a/live/blog/index.html +++ b/live/blog/index.html @@ -88,6 +88,7 @@

Articles

    2023

    +
  • Aug 29 - Godot layers and masks notes
  • Aug 27 - Porting the FlappyBird clone to Godot 4.1 devlog 2
  • Aug 20 - Set up a pastebin alternative with PrivateBin and YOURLS
  • Jul 24 - Set up a media server with Jellyfin, Sonarr and Radarr
    • diff --git a/live/blog/rss.xml b/live/blog/rss.xml index 82a3256..e646e8e 100644 --- a/live/blog/rss.xml +++ b/live/blog/rss.xml @@ -22,6 +22,30 @@ Luévano's Blog https://blog.luevano.xyz + + Godot layers and masks notes + https://blog.luevano.xyz/g/godot_layers_and_masks_notes.html + https://blog.luevano.xyz/g/godot_layers_and_masks_notes.html + Tue, 29 Aug 2023 10:10:06 GMT + English + Gamedev + Gdscript + Godot + Some notes I took regarding Godot's confusing collision layers and masks. + The first time I learned about Godot’s collision layers and masks (will refer to them just as layers) I thought I understood them only to find out that they’re a bit confusing when trying to figure out interactions between objects that are supposed to detect each other. On my last entry where I ported the FlappyBird clone to Godot 4.1 I stumbled upon an issue with the bird not colliding properly with the pipes and the ceiling detector not… well, detecting.

    +

    At the end of the day the issue wasn’t that the layers weren’t properly setup but rather that the API to change the state of the collision layers changed between Godot 3 and Godot 4: when calling set_collision_layer_value (or .._mask) instead of specifying the bit which starts at 0, the layer_number is required that happens to start at 1. This was a headache for like an hour and made me realise that I didn’t understand layers that well or else I would’ve picked the error almost instantly.

    +

    While researching I found two really good short explainations that helped me grasp the concepts better in the same post, the first a bit technical (by Bojidar Marinov):

    +
      +
    • If enemy’s mask and object’s mask are set to 0 (i.e. no layers), they will still collide with the player, because the player’s mask still includes their respective layers.
      • +
    • Overall, if the objects are A and B, the check for collision is A.mask & B.layers || B.mask & A.layers, where & is bitwise-and, and || is the or operator. I.e. it takes the layers that correspond to the other object’s mask, and checks if any of them is on in both places. It will then proceed to check it the other way around, and if any of the two tests passes, it would report the collision.
      • +
    +

    And the second, shorter and less technical but still powerful (in the same post linking back to Godot 3.0: Using KinematicBody2D):

    +
      +
    • collision_layer describes the layers that the object appears in. By default, all bodies are on layer 1.
      • +
    • collision_mask describes what layers the body will scan for collisions. If an object isn’t in one of the mask layers, the body will ignore it. By default, all bodies scan layer 1.
      • +
    +

    While the complete answer is the first, as that is how layers work, the second can be used like a rule: 1) the layer is where the object lives, while 2) the mask is what the object will detect.

    ]]>     +     Porting the FlappyBird clone to Godot 4.1 devlog 2 https://blog.luevano.xyz/g/flappybird_godot_devlog_2.html @@ -60,7 +84,7 @@

Porting to Godot 4

-

Disclaimer: I started the port back in Godot 4.0 something and left the project for a while, then opened the project again in Godot 4.1, and it didn’t ask to convert anything so probably nowadays the conversion is better.

+

Disclaimer: I started the port back in Godot 4.0 something and left the project for a while, then opened the project again in Godot 4.1, and it didn’t ask to convert anything so probably nowadays the conversion is better. Godot’s documentation is pretty useful, I looked at the GDScript reference and GDScript exports and that helped a lot.

General changes

These include the first changes for fixing some of the conflicting code to at least make it run (no gameplay) as well as project settings adjustments.