britzl:
nother thing which will likely happen this year is that we start to move the 2d and 3d physics engines into their own extensions. Initially as internal extensions, but eventually they might become external extensions. Splitting up the physics into a 2d and 3d api will allow us to more rapidly add physics engine specific features and terminology into each api.
So physics will became an API, it would be like we use now the 3d Bullet but for 2d and 3d?
britzl
July 5, 2025, 7:33pm
22
Yes, thereās already an API for Box2D:
There will at some point be an equivalent API for 3D physics
1 Like
What physics does Defold use by default?
I am asking because of this issue here:
opened 04:45AM - 02 Jul 25 UTC
bug
engine
editor
physics
**Describe the bug (REQUIRED)**
Box2D Version 3 does not build on Windows
**To ⦠Reproduce (REQUIRED)**
Create an appmanifest with Box2D Version 3 selected and attempt to build on Windows.
**Defold version (REQUIRED):**
1.10.2
Some of the sample output
```
lld-link: error: undefined symbol: void * __cdecl b2Alloc(int)
>>> referenced by D:\a\defold\defold\engine\physics\src\physics\box2d_defold\box2d_defold_physics.cpp:629
>>> libphysics_2d_defold.lib(box2d_defold_physics.cpp.4.o):($LN9)
>>> referenced by D:\a\defold\defold\engine\physics\src\physics\box2d_defold\box2d_defold_physics.cpp:629
>>> libphysics_2d_defold.lib(box2d_defold_physics.cpp.4.o):($LN9)
>>> referenced by D:\a\defold\defold\tmp\dynamo_home\ext\include\box2d_defold\Box2D\Collision\Shapes\b2GridShape.h:21
>>> libphysics_2d_defold.lib(box2d_defold_physics.cpp.4.o):($LN4)
>>> referenced 1 more times
```
From what I got, you will remove the 2D Physics interary from Defold to stay only in the component, is this? I like the idea tbh, the minimalism of Defold is what got meā¦
britzl
July 8, 2025, 8:27am
24
For 2D physics Defold uses Box2D v 2.x. For 3D physics it uses Bullet.
You can opt in to Box2D v 3.x using an app manifest. You can also use an app manifest to opt-out of any physics if your game doesnāt need it.
1 Like
Thx I knew this was possible but didnāt know the wayā¦
Where I can get help compiling the Engine, I was wanting to help the coding but culd not compile with the python ./scripts/build.py build_engine -- --verbose
It prompts that graphics_ddf.cpp is being created more than once. I just wanted to add support to isometric tilemaps like in tiledā¦
Sorry if this is not the best place to postā¦
britzl
July 8, 2025, 3:49pm
26
Please join our Discord server and head to the source-code channel.
1 Like