Maratis forum - when are physics shapes and objects deleted?

Re: when are physics shapes and objects deleted?

dummy@example.com (255) — Tue, 15 Oct 2013 10:31:19 +0000

Still, I consider this not the expected behavior.
If you do a lua function "deleteEntity()" I'm sure you will delete all the associated physics objects, so the same should be with C++.
You can make MScene do this, while the MOEntity code shouldn't need to be touched. I think this would keep a good design/structure.

Re: when are physics shapes and objects deleted?

dummy@example.com (anael) — Sat, 12 Oct 2013 08:52:58 +0000

Yes, in this case you will need to destroy or at least deactivate the physics object manually just before :

MPhysicsProperties * phyProps = plane->getPhysicsProperties();
if(phyProps)
physics->deactivateObject(phyProps->getCollisionObjectId());

Re: when are physics shapes and objects deleted?

dummy@example.com (255) — Sat, 12 Oct 2013 00:49:44 +0000

This is "preparing", "initializing", but I'm talking about deleting an entity or its physics properties. The actual physics objects and shapes are NOT deleted.
I was just guessing, reading the source code, but now I've done a test and it's actually a real bug.

Create a project, create a falling box and a plane with mass 0.00 to stop the falling box.
In your game plugin do

MOEntity* plane = scene->getEntityByName("Plane");
scene->deleteObject(plane);

Run the game, the box will fall and it will soon be stopped by the invisible physics object left by the plane entity.

Re: when are physics shapes and objects deleted?

dummy@example.com (anael) — Fri, 11 Oct 2013 22:33:49 +0000

shapes and objects are automatically deleted by the physics context clear() function
MBulletContext::clear(void)

clear is called by MBulletContext::init, itself called by MScene::preparePhysics

when are physics shapes and objects deleted?

dummy@example.com (255) — Fri, 11 Oct 2013 19:33:20 +0000

I see that MPhysicsContext has deleteShape() and deleteObject() method but I don't see them used anywhere.
If I do

entity->createPhysicsProperties();

physics properties and constraint are SAFE_DELETEd which means

delete pointer;
pointer = NULL;

but the physics shape and object are not deleted.
I then call

scene->prepareCollisionShape(entity);
scene->prepareCollisionObject(entity);

but in these functions there is no deleting of the previous object neither.